2021 CEDAR Workshop Virtual Poster Session

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Lightning detection in radio spectrograms based on convolutional neural networks

A. Kundrát, V. Maslej-Krešňáková, Š. Mackovjak, P. Butka

Abstract

Current measuring devices could detect lightning strokes thousands of kilometers away. It results from measurements of electromagnetic pulses in a very low frequency (VLF) range below 30 kHz. By subsequent analysis, it is possible to locate lightning stroke and characterize properties of the environment between lightning stroke and detector. Machine learning techniques can significantly simplify the detection and analysis of those pulses recorded in spectrograms. The goal of this bachelor thesis is to get acquainted with the basics of convolutional neural networks (CNN) and with their usage in the detection of specific events (electromagnetic pulses) on figures (spectrograms).

Presented by

Adrian Kundrat <adrian.kundrat@student.tuke.sk>

Institution

Technical University of Košice, Department of Cybernetics and Artificial Intelligence

Keywords

deep learning, neural network, object detection, spectrogram, lightning stroke, dispersion, tweek

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Available June 23, 3:30-5 PM Mountain time

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Observing Non-Migrating Diurnal Tides from Geostationary Orbit with GOLD

Christopher Krier, Scott England, and the GOLD Science Team

Abstract

One pathway to troposphere-thermosphere coupling is the upward propagation of non-migrating tides. At present, there is a gap of observational constraints on these tides in middle thermosphere temperature and their impact on thermospheric composition is not well understood. From geostationary orbit above the mouth of the Amazon River, the Global Scale Observations of the Limb and Disk (GOLD) mission provides valuable daytime images of neutral temperature and the ratio of atomic oxygen to molecular nitrogen column densities (O/N2). Here we use a novel approach to deduce the dominant non-migrating diurnal tides from the combined temperature-O/N2 dataset. In this poster, we provide results from application to GOLD data, and we assess the impact of ionospheric contamination by O+ radiative recombination on the deduced tides.

Presented by

Christopher Krier

Institution

Virginia Tech

Keywords

Tides, thermosphere, temperature, composition, airglow

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Available June 23, 3:30 - 5:00 PM Mountain Time

Jing Liu

Abstract

Presented by

Jing Liu

Institution

Shandong University at Weihai

Keywords

Global Responses of Gravity Waves and Zonal Mean Winds to the Madden-Julian Oscillation and the Latitudinal Dependence of Their Relations using MERRA-2

Jintai Li 1，2, Xian Lu1, and Jens Oberheide1

Abstract

Using 17 years of Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) data, significant responses of GW variances and zonal winds to the Madden-Julian Oscillation (MJO) are identified globally during boreal winter, and their relations are examined for the first time. The relative anomalies of GW variances range from -4% (phase 7) to 8% (phase 4) in tropics, and -20% (phase 1) to 20% (phase 5) in the northern polar region (NPR). The absolute anomalies of zonal winds are from -3–3 m/s and -4–8 m/s in tropics and NPR, respectively. The vertical and latitudinal structures of GW and wind responses to MJO phases show coherent patterns, suggesting their correlation. Further analysis implies that the MJO modulation of GWs likely drives that of zonal winds around low- and mid-latitude stratopause region, while in NPR, an opposite scenario (wind responses to MJO drive GW responses) is observed.

Presented by

Jintai Li <jli23@alaska.edu>

Institution

1, Clemson University 2, Geophysical Institute, University of Alaska Fairbanks.

Keywords

Gravity Wave, MJO, MERRA-2, Polar Vortex, Coupling

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Available June 23rd, 3:30pm - 5:00pm Mountain Time (MT)

Volcano-Generated Ionospheric Disturbances: Comparison of GITM-R Simulation with GNSS Observation

Justin Tyska, Yue Deng, Cissi Y. Lin, Shun-Rong Zhang

Abstract

Geophysical events such as earthquakes, tsunamis, and volcanic eruptions can create disturbances in the ionosphere-thermosphere (IT) system by propagation of the developed acoustic-gravity waves (AGWs). These disturbances can be observed by ground based and spaceborne Global Navigation Satellite Systems (GNSS) and used to analyze various properties of the initial perturbation such as localization [1], wavelength [2], and total energy content [3]. The focus of this study is to simulate ionospheric Total Electron Content (TEC) variations induced by volcanic eruption using a global circulation model and to subsequently compare the simulated results to GNSS data. Unlike tsunamis and earthquakes, volcanic eruption is more or less like a point source at a fixed geographic location causing relatively localized perturbation. Simulations using the Global Ionosphere-Thermosphere Model with local mesh refinement (GITM-R) are performed to capture mesoscale subtleties in the regions near the volcano [4]. GITM’s lower boundary is at ~100 km altitude, thus an analytical AGW propagation model is used in conjunction with a volcanic source model to specify GITM’s lower boundary. The simulated TEC variations are compared to GNSS data to demonstrate GITM’s ability to resolve mesoscale acoustic-gravity waves signals induced by volcanic eruptions as well as attempts to link TEC waveform characteristics to volcanic source parameters.

Presented by

Justin Tyska

Institution

University of Texas at Arlington

Keywords

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Available Wednesday, June 23rd, 1pm-3pm

Model for Acoustic Gravity wave Numerical Simulation in Planetary atmospheres

Sarthak Srivastava, Amal Chandran

Abstract

Presented by

Sarthak Srivastava

Institution

Nanyang Technlogical University

Keywords

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Available Tuesday, 22-Jun, 15:30-1700 MT

Thermospheric Traveling Atmospheric Disturbances in Austral Winter from GOCE and CHAMP

Shuang Xu, Sharon L. Vadas, Jia Yue

Abstract

In this study, we analyze the thermospheric density data provided by the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) during June–August 2010–2013 at ~260 km altitude and the Challenging Minisatellite Payload (CHAMP) during June–August 2004–2007 at ~370 km altitude to study high latitude traveling atmospheric disturbances (TADs) in austral winter. We extract the TADs along the satellite tracks from the density for varying Kp, and linearly extrapolate the TAD distribution to Kp=0; we call these the geomagnetic “quiet time” results here. We find that the quiet time spatial distribution of TADs depends on the spatial scale (along-track horizontal wavelength ) and altitude. At z~260 km, TADs with ≤330 km are seen mainly around and slightly downstream of the Southern Andes-Antarctic region, while TADs with >800 km are distributed fairly evenly around the geographic South pole at latitudes ≥60˚S. At z~370 km, TADs with ≤330 km are relatively weak and are distributed fairly evenly over Antarctica, while TADs with >330 km make up a bipolar distribution. For the latter, the larger size lobe is centered at ~60˚S, and is located around, downstream and somewhat upstream of the Andes/Antarctic Peninsula, while the smaller lobe is located over the Antarctic continent at 90˚–150˚E. We also find that the TAD morphology for Kp≥2 and >330 km depends strongly on geomagnetic activity, likely due to auroral activity, with greatly enhanced TAD amplitudes with increasing Kp.

Presented by

Shuang Xu <xushuang9999@gmail.com>

Institution

Hampton University, Department of Atmospheric and Planetary Sciences

Keywords

traveling atmospheric disturbance, gravity waves, thermosphere, secondary wave generation

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Available June 23, 15:30-16:30 MDT

Assimilative Modeling of the Day-to-Day Variability of the Equatorial Electrojet and its Longitudinal Dependence Using Ground- and Space-Based Magnetometer Data

Chuan-Ping Lien [1], Tomoko Matsuo [1], Astrid Maute [2], Claudia Stolle [3]

Abstract

The equatorial electrojet (EEJ) is an important manifestation of ionospheric electrodynamics. The day-to-day changes of EEJ result from E-region dynamo processes primarily driven by highly variable atmospheric tides propagating from the lower atmosphere. The extent of day-to-day tidal variability is not well understood due to the sparse spatiotemporal coverage of measurements, and inadequately modeled lower- and middle-atmosphere dynamics. In this study, observations of ground-level magnetic perturbations are utilized to constrain the magnitude and phase of tidal waves specified as lower boundary conditions in the Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM), with the help of an ensemble transform technique. TIE-GCM ensemble simulations are driven by realistic magnetospheric and wave forcing specified by AMGeO analysis and MERRA meteorological reanalysis, respectively, and the 3D Dynamo Model is used as part of forward modeling of ground-level magnetic perturbations. Modeled EEJ is validated with CHAMP magnetometer data. A case study designed for solar minimum March conditions showcases the use of routinely available ground-based magnetometer data for improving the model’s ability to reproduce the observed characteristics of day-to-day changes of the EEJ.

Presented by

Chuan-Ping Lien

Institution

[1] University of Colorado Boulder, CO, USA, [2] High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO, USA, [3] German Research Centre for Geosciences, Potsdam, Germany

Keywords

EEJ, Ionospheric Electrodynamics, Data Assimilation

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Available June 23 3:30pm - 5:00pm MT

FAST TEAMS in situ measurements of plasma convection

E J Lund[1], K Zhao[2], N Nowrouzi[1], L M Kistler[1], N Kitamura[3]

Abstract

Cold plasma has historically been difficult to measure in situ with particle detectors due to issues such as spacecraft charging, spacecraft motion, and low energy resolution in the range of interest. While most spacecraft tend to charge positively due to photoelectron emission, the Fast Auroral Snapshot (FAST) mission was observed to have relatively low charge most of the time and to charge negatively. FAST was equipped with the Time-of-flight Energy Angle Mass Spectrometer (TEAMS), which measured H+, He+. and O+ distributions at energies of 1-12000 eV. The energy and angle resolution of TEAMS was sufficient to measure the difference between the O+ ram velocity and the spacecraft velocity. This difference is due to convection of the plasma. Since our measurement does not rely on electric field data, we can compute 2-D convection velocities without using axial electric field measurements. This data product will be included in CDF files we are providing to NSSDC for community use.

Presented by

Eric Lund <Eric.Lund@unh.edu>

Institution

[1]Space Science Center, University of New Hampshire, Durham, USA; [2]Nanjing University of Information Science and Technology, China; [3]University of Tokyo, Japan

Keywords

Plasma convection, particle measurements, data set, FAST

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Available 2021-06-22/15:30 to 17:00 MDT

John Haiducek

Abstract

LightDA is a flexible and parallel software library to support data assimilation. The core library provides generic interfaces for defining model states, observation types, forward operators, localization weights, and assimilation filters. New components can be added at runtime without re-compiling the core library. LightDA has been tested on a simple 1-D advection solver, and efforts are in progress to create componets for assimilating total electron content observations into the SAMI3 (SAMI3 is Another Model of the Ionosphere) model.

Presented by

John Haiducek

Institution

US Naval Research Laboratory

Keywords

Data assimilation, ionosphere, SAMI3

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Available June 24, 1530-1700 MDT

pysat Instrument for CHAIN network

Jonathon Smith

Abstract

The Canadian High Arctic Ionospheric Network (CHAIN) is dedicated to the understanding of planetary environments that are affected by variable solar output. The Python Satellite Data Analysis Toolkit (pysat) is a package providing a simple and flexible interface for downloading, loading, cleaning, managing, processing, and analyzing scientific measurements. Although pysat was initially designed for in situ satellite observations, it now supports many different types of ground- and space-based measurements. The effort here is to create a module to include CHAIN data in the pysat penumbra. The results of this effort will make the use of CHAIN data easier to fold into science utilizing other datasets already included in pysat. Additionally, inclusion in pysat forces the data collection, storage, and access to be made consistent with the rest of the pysat ecosystem. This consistency trivializes use of CHAIN data for scientists who are new to the CHAIN data.

Presented by

Jonathon Smith

Institution

NASA Goddard Space Flight Center

Keywords

pysat, CHAIN, ionosphere, high-latitude, GPS, irregularity, pyHC, software

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Available June 23 15:30-17:00

Reprocessing of data from Fabry-Perot interferometers (FPI) belonging to the IGP network of optical instruments

Juan Carlos Barbaran Meza

Abstract

IGP network of optical instruments has two types of observation instruments: Fabry-Perot Interferometers (FPI) and All-Sky imagers (ASI). The FPI can obtain two-dimensional interferograms that are used to study phenomena in the upper atmosphere, like winds and temperatures of neutral winds. Since the implementation of the FPI network (2015) a processing technique based on Gaussian fits has been used. A recent improvement of this technique has been released, and some new enhancements are available, like interlocks in the selection of data, or automatic modelling of optical defects. Given that the new processing technique has potentially the ability to generate better products, reprocessing of the IGPs optical database is being evaluated. First, the two methods need to be compared. In this work we present an analysis of the two methods in comparison, showing differences, advantages, and possible improvements to implement.

Presented by

Juan Carlos Barbaran Meza <roj-cielo01@igp.gob.pe>

Institution

Instituto geofísico del Perú

Keywords

Fabry-Perot Interferometers, neutral winds

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Available June 25th 9-10 am PET

Calibration of Swarm-E (e-POP) suprathermal electron imager (SEI) flux

Jun Liang

Abstract

Presented by

Jun Liang

Institution

University of Calgary, Canada

Keywords

Suprathermal electron imager, electron precipitation flux

Yang Pan, Mingwu Jin, Shunrong Zhang, Yue Deng

Abstract

Total electron content (TEC) measures the plasma environment and plays an important role in studying the ionosphere. However, the incompleteness of the global TEC maps from the Massachusetts Institute of Technology (MIT)- TEC database due to the limited coverage of the ground stations curbs the study of the TEC especially on the ocean part. The generative adversarial network (GAN) has been applied in image completion. We apply two GAN models, deep convolutional (DC)-GAN and spectral-normalized patch (SNP-GAN) learning the distribution of Internaltional Global Navigation Satellite System (IGS)-TEC data. It shows that SNP-GAN outperforms DCGAN qualitatively and quantitatively, and the potential in identifying meso-scale TEC structure with upscaled resolution.

Presented by

Yang Pan <yang.pan@mavs.uta.edu>

Institution

University of Texas at Arlington, Department of Physics

Keywords

Total Electron Content, Neural Networks

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Available 15:30PM to 17:00PM MDT June 23rd 2021

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An undergraduate-to-graduate bridge program: Significant Opportunities in Atmospheric Research and Science (SOARS)

Astrid Maute1, McArthur Jones Jr,., Kadidia Thiero (SOARS Program lead & PI)

Abstract

The Significant Opportunities in Atmospheric Research and Science (SOARS) (https://soars.ucar.edu/) is an undergraduate-to-graduate bridge program designed to broaden participation of historically underrepresented communities in atmospheric and related sciences. The SOARS program is funded by the National Science Foundation, and others. The program is built on a strong mentoring program during a summer research experience at the National Center for Atmospheric Research (NCAR) and other Boulder research institutions, such as NOAA ESRL, CU Boulder, etc. SOARS Protégés participate in professional development and workshops such as scientific communication and writing, data science and computer science, in addition to conducting original research guided by a research mentor(s). Writing mentors, computing mentors, community mentors, as well as peer mentors support the Protégé through the summer months. The cohorts of SOARS Protégés form a supportive community during the year which is facilitated by the SOARS program. Additionally, over 90% of the SOARS Protégées advance to graduate school, and many have entered the works force with at least an MS degree. Conference travel, tuition assistance, and year-long mentoring are features that support students. With this poster we would like to raise the awareness amongst students and faculty of the SOARS program in the upper atmosphere research community, and encourage deserving undergraduate to apply to the program.

Presented by

Astrid Maute

Institution

National Center for Atmospheric Research, US Naval Research Laboratory, University Corporation of Atmospheric Research

Keywords

undergrad-to-graduate bridge program

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Available 15:30 - 17:00

Creating opportunities for student training and citizen science using ScintPi

Isaac Wright, Josemaria G. Socola, and Fabiano S. Rodrigues

Abstract

Advances in space sciences can benefit from the engagement and training of undergraduate students and participation of citizen scientists. Therefore, as a physics undergraduate student we were assigned a project with two main objectives: (#1) To learn more about research in space sciences while developing transferable skills, and (#2) to develop resources for the assembly, maintenance, and visualization of data of a low-cost GPS-based ionospheric scintillation monitor - ScintPi (Rodrigues and Moraes, 2019) that would assist citizen science initiatives. Here, we present our contribution to these goals consisting of the development of a data processing pipeline for ScintPi sensor data and resources for citizen scientists interested in constructing and processing data from ScintPi.

Presented by

Isaac Wright <igw180000@utdallas.edu>

Institution

The University of Texas at Dallas, W. B. Hanson Center for Space Sciences

Keywords

Ionosphere, Sensors, Scintillation

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Available Wednesday, June 23 3:30pm to 5:00pm MT

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CROWDSOURCING IONOGRAM SCALING: A CITIZEN SCIENCE PROJECT

Stephany Ccanto, Enrique Rojas, Amanada Vilchez, Marie Suazo, Alessandro Strobbe

Abstract

Citizen science (CS) is defined as a form of research collaboration or data gathering performed by non-experts or untrained individuals. CS projects benefit scientists by providing resources for data processing, gathering, pattern recognition, etc. On the other hand, for volunteers, CS represents the democratization of science, and the opportunity to be involved in local issues as well as a strong public education aspect. In this work, we will use zoouniverse.org to create a CS project using data from Jicamarca Radio Observatory’s ionosonde. Participants will use a built-in draw tool to identify the ordinary and extraordinary lines from an ionogram power image, which then can be used for parameter estimation. Furthermore, we will describe our plans for data management and public engagement. We hope this work will motivate our community to use CS projects both as a scientific and an outreach approach.

Presented by

Stephany Ccanto Mayhua <cjun.ccanto.mayhua.stephany@gmail.com>

Institution

Peruvian University of Applied Sciences, Cornell University, Ciencia Ciudadana Peru, Sociedad Secular Humanista del Perú

Keywords

Citizen Science, Zooniverse, Ionogram Scaling

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Available June 24th 3:30-5:30pm MDT

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Resolving the Spatial/Temporal Ambiguity of the EIA and ETA Using a LEO CubeSat Swarm Configuration

Anton Buynovskiy, David Fitzpatrick, Zoe Lee, Scott Palo, Jeffrey Thayer, Marcin Pilinski

Abstract

SWARM-EX is an NSF-funded CubeSat mission in which 3 identical formation-flying satellites will make in-situ measurements in LEO to address outstanding aeronomy questions related to the evolution of the Equatorial Ionosphere Anomaly (EIA) and Equatorial Thermosphere Anomaly (ETA). To address these aeronomy questions, SWARM-EX will have two main science payloads: a Langmuir Probe from ASTRA LLC to measure the plasma density, and the Flux-Probe-Experiment (FIPEX) from Stuttgart Institute of Space Systems to measure the neutral atmosphere. SWARM-EX will also perform several secondary measurement demonstrations to explore the use of CubeSat swarms as novel, distributed instruments. This poster will explore the primary science questions dealing with the ionospheric-thermospheric features and also focus on the development of FIPEX and the Langmuir Probe that will be used to make the desired in-situ measurements.

Presented by

Anton Buynovskiy <anbu4369@colorado.edu>

Institution

University of Colorado Boulder

Keywords

SWARM, EIA, ETA, TIDs, TADs, ionosphere, thermosphere, Langmuir Probe, FIPEX

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Available June 23rd, 2:30pm-5pm MST

Abstract

It has been over a year since measurements of mesosphere and lower thermosphere (MLT) winds have been obtained with the SIMONe Peru radar. This modern multistatic specular meteor radar, placed on the central coast of Peru, has its transmitter located at the Jicamarca Radio Observatory (11.95° S, 76.87° W, dip angle 1°). This work will show some results of the climatology of diurnal and semidiurnal tides obtained from the analysis of zonal and meridional mean winds that have been estimated at heights between 80-100 km using one year of data (Nov 2019 - Oct 2020). The monthly and seasonal variation of tide amplitudes will be described. From the results we have seen that diurnal tides are more intense than semidiurnal tides, which is typical at low latitudes and that diurnal tide is more intense in August and September. These and others results will also be described in this work.

Presented by

José Suclupe

Institution

¹Radio Observatorio de Jicamarca, Instituto Geosfísico del Perú, Lima, Perú.

Keywords

Diurnal and semidiurnal tides, equatorial MLT region

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Available June 23rd 15:30-17:00 MDT

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Estimation of ionospheric electron densities from 150 km echoes

Kevin Luyo, Enrique Rojas, Marco Milla

Abstract

The 150 km echoes are strong coherent radar echoes observed with equatorial ionospheric radars that have been studied for 60 years, nevertheless, the exact physical mechanism that produces them is still a matter of debate. Mounting evidence suggests that the gaps in these echoes correspond to heights where the local upper hybrid frequency is a multiple of the gyrofrequency. In this work, we use this relation to estimate electron densities from historical SNR data collected with the Jicamarca radar operating in JULIA (Jicamarca Unattended Long-term Investigations of the Ionosphere and Atmosphere) mode. The analysis was applied to SNR maps with a single gap. We compared these estimates with IRI and SAMI2 outputs. Furthermore, we will show some preliminary results of density estimates obtained by assimilating the 150 km radar data and ionograms measured with digisonde.

Presented by

Kevin Luyo

Institution

Universidad Nacional del Callao

Keywords

JULIA, 150 km echoes, gap, electron density

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Available June 23 3:30-5 MT

Space weather effects on the Brazilian equatorial and low-latitude ionospheric Maximum Usable Frequency (MUF) during the Saint Patrick’s Day geomagnetic storm

Onyinye Gift Nwankwo, Claudia M N Candido, and Fabio Becker-Guedes

Abstract

In this work, we present a study of the Brazilian equatorial and low-latitude ionospheric response during the Saint Patrick’s Day geomagnetic storm. This ICME-driven storm was considered to be the first intense storm of solar cycle 24 and presented a long-duration main phase. Ionospheric parameters such as h’F, hmF2, foF2, and MUF, taken from Digisondes installed at Sao Luís (dip latitude 5°S) and Campo Grande (dip latitude 22.3°S) were analyzed. The results showed two sharp F-layer uplifts in the local morning and afternoon, associated with Prompt Penetration Electric Field, during which there was decreasing MUF in comparison to the quietest periods in both regions. This work may contribute to a better understanding of the effects of space weather events on HF, and long-distance radio communications through the ionosphere.

Presented by

Onyinye Gift Nwankwo <nwankwo.gift@inpe.br>

Institution

National Institute for Space Research (INPE), Brazil/ Department of Space Geophysics

Keywords

Geomagnetic storm, Equatorial and Low-latitude Ionosphere, Maximum Usable Frequency, Radio Communication.

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Available June 23rd 3:30-5pm MDT

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Validation of IVM Ion Density from the COSMIC-2 Mission

Qian Wu1,2, N. Pedatella1,2, J. Braun1, M. Chou1

Abstract

COSMIC-2 IVM (Ion Velocity Meter) instrument measures in-situ ion densities, The TGRS (Tri-GNSS Radio Occultation System) receiver observes slant TEC, which can be used to derive electron density profiles. Since COSMIC-2 has 6 satellites and each has an IVM instrument, validating all 6 instruments for consistency will e invaluable for future studies of global scale structures in the ionosphere arising from the tides and planetary waves. The in-situ electron density can be derived from the TGRS slant TEC data when the observational geometry is such that the GNSS-to-LEO ray-path is aligned with COSMIC-2 satellite velocity in the forward or backward diredtions. We will present the results of the comparison and describe the correction applied to the IVM ion density.

Presented by

Qian Wu

Institution

1COSMIC/UCAR, 2HAO/NCAR, Boulder, CO

Keywords

Equatorial Ionosphere, measurement calibration

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Available June 23, 15:30PM to 17:00 PM

Modeling Studies of the Morphology of Equatorial F-region Plasma Drifts

Sam Shidler and Fabiano S. Rodrigues

Abstract

The equatorial ExB plasma drifts are an important parameter for controlling the structure and morphology of ionospheric plasma at low magnetic latitudes. Additionally, the behavior of the plasma drifts have been linked to the stability of the ionosphere and the generation of plasma irregularities. Here we present the results of two modeling studies examining the local time versus height variability of the quiet-time equatorial F-region ExB plasma drifts during equinox high solar flux conditions. Both models rely on a two-dimensional field line integrated description for the low-latitude ionospheric electrodynamics. Additionally, we focus on results in the Peruvian longitude sector to facilitate a comparison of model drifts with mean drifts derived from long-term observation made by the Jicamarca incoherent scatter radar (ISR).

Presented by

Sam Shidler <sas141430@utdallas.edu>

Institution

University of Texas at Dallas, William B. Hanson Center for Space Sciences

Keywords

Plasma Drifts, Modeling, Ionosphere

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Available June 23rd 3:30pm - 5:00pm MT

Thermospheric Winds Over Huancayo, Peru

Sovit Khadka(1), Andrew Gerrard(1), Mariangel Fedrizzi(2,3), Patrick Dandenault(4), and John Meriwether(1)

Abstract

We used ground-based optical measurement and simulated results to study the climatology of the equatorial thermospheric winds. The continual 24-hour observations of winds were made using the Second‐generation, Optimized, Fabry‐Perot Doppler Imager (SOFDI), located near the geomagnetic equator at Huancayo, Peru. A comparative analysis of the observed SOFDI 630-nm OI emission data at around 250 km altitude and corresponding wind results from several empirical and physics-based models will be presented for July 2014, August 2014, and June 2015. Additionally, we discuss the mechanism of wind variability based on the overall agreement results between the observed and modeled wind data.

Presented by

Sovit Khadka

Institution

(1)New Jersey Institute of Technology, Newark, NJ, USA, (2)University of Colorado, Boulder, CO, USA, and (3)Space Weather Prediction Center, NOAA, Boulder, CO, USA, (4)Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA

Keywords

Equatorial Thermosphere/Ionosphere, SOFDI, Observed and Modeled Wind

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Available 17:30 - 19:00 EDT

Investigations of oxygen dayglow emission variability over low latitudes under the influence of equatorial electrodynamic processes

Sunil Kumar and Duggirala Pallamraju

Abstract

Earth’s upper atmosphere (UA) over low latitudes is primarily influenced by equatorial electrodynamics. The dynamics of UA and ionosphere thermosphere coupling processes can be investigated by measuring dayglow emissions. Capability to measure dayglow emissions at different wavelengths using a multi-wavelength imaging spectrograph using echelle grating, MISE, over a large field-of-view gives us a unique opportunity to investigate the UA behaviour over large spatial extents. In the present work, influence of equatorial electrodynamics over off-equatorial and low-latitudinal regions in Indian longitudes is described using OI 630.0 nm and OI 777.4 nm dayglow emissions. The spatial range of coverage of optical data is from 4⁰-18⁰ magnetic latitude. The dayglow data during Jan-Feb 2020 is analyzed and latitudinal and altitudinal variation in the UA processes is investigated. The details of these results will be presented.

Presented by

Sunil Kumar

Institution

Physical Research Laboratory, Ahmedabad, India

Keywords

Keywords: OI630.0nmdayglow,OI777.4nmdayglow,Equatorialelectrojet, Equatorial ionization anomaly, High-resolution spectrograph, Upper atmospheric dynamics

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Available June 22,23,24th 15:30 - 17:00 MDT

Equatorial Plasma Depletions Observed in 135.6 [nm] Airglow from High Earth Orbit

Vincent James Adkins

Abstract

135.6 nm airglow provides information about O+ during the post-sunset hours. Structures that form during this timeframe can be viewed as variations in airglow brightness, but the observations can only be made from orbit as the 135.6 nm light is quickly absorbed below the middle thermosphere. Low Earth orbit is used to view these structures in higher resolution, but typically provides instruments with a relatively small field-of-view compared to the size of ionospheric structures, whereas high earth orbit can be used to view the same structures across several hours and over a large region of the Earth. We have observations of this nature from IMAGE-FUV SI-13 during solar maximum and we now also have more recent observations from GOLD during the current solar minimum. Here, we present an automated method looking at GOLD data and an example observation with a focus on size, spacing, and drift speeds of the equatorial spread-F bubbles (plasma bubbles) detected.

Presented by

Vincent Adkins <vja9999@vt.edu>

Institution

Virginia Polytechnic Institute and State University: Department of Aerospace Engineering

Keywords

GOLD, Spread-F, Plasma Bubble, Plasma Depletion

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Available June 23rd, 1530-1430 (MT)

The relation between hmF2 and radio occultation scintillation amplitude index RO-S4 index observed using FORMOSAT-7/COSMIC-2

Yi Duann, Loren Chang, Chi-Kuang Chao, Jann-Yenq Liu, Tung-Yuan Hsiao, Shih-Ping Chen

Abstract

The data from the FORMOSAT-7/COSMIC-2 (F7/C2) primary Tri-GNSS Radio-occultation System (TGRS) space weather products: relative total electron content (TEC), scintillation amplitude index (S4), and electron density (Ne) profile have been released. This study focuses on the correlation of F7/C2 radio occultation scintillation amplitude (RO-S4) index below 500 km and the height of peak electron density in F2-layer (hmF2), and the relation with the occurrences of equatorial plasma bubbles (EPBs) due to plasma uplift. Chou et al. (2020) indicates that the casual relationship of EPBs and the hmF2 should be examined in more detail. Ghosh et al. (2020) presents that the hmF2 elevated to higher altitudes by pre-reversal enhancement (PRE) around evening terminator due to eastward electric field at the magnetic equator, while the electron density (Ne) in the F-region shows negative correlation with peak PREs that could be driven by fountain effect.

Presented by

Yi Duann

Institution

Center for Astronautical Physics and Engineering, National Central University, Taoyuan, Taiwan

Keywords

FORMOSAT-7/COSMIC-2, F-region, RO-S4, hmF2, EPB

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Available June 23rd 15:30-17:00 MDT

▼ IRRI Back to top

Abstract

We present an imaged-based convolutional long short-term memory (convLSTM)-based machine learning algorithm to predict storm-time ionospheric irregularities. The images are GNSS-derived rate of TEC change index (ROTI) maps. Unlike existing methods that are either focused on irregularities at individual locations or treat the irregularity prediction as a classification problem, the convLSTM architecture forecasts an entire regions’ storm-time ionospheric irregularity occurrence and intensity values. We implemented the convLSTM model with a custom loss function (convLSTM-Lc) that includes two weighted loss functions and a dynamic penalty on difference between the truth and the predicted values. The convLSTM-Lc is trained with real ROTI data collected during Jan 1-Aug 7, 2015 from GNSS receivers located in (45-90N, 0-180W). Test results after Oct 20 in 2015 show that the convLSTM-Lc algorithm can forecast irregularity structures more accurately than a convLSTM model that implements conventional loss functions. The improvement is particularly evident in prediction of ROTI maps with up to a 30-minute lead time. The model also significantly outperforms the persistence model according to statistical classification metrics with a lead time of up to 60 minutes. Furthermore, though predictive capability of both convLSTM-Lc and the persistence model degrade over the increasing prediction lead time, the degradation speed for convLSTM-Lc is lower than that of the persistence model.

Presented by

LEI LIU

Institution

Ann and H. J. Smead Aerospace Engineering Sciences Department, University of Colorado Boulder, Boulder, CO, USA

Keywords

High-resolution Simulations of Primary Gradient Drift Instability in Polar Cap Patches

M. Redden, M. Zettergren, L. Lamarche, K. Deshpande, M. Hirsch

Abstract

Patches of high-density plasma (100-1000 km scales) are commonplace in the polar cap F-region ionosphere. For northward IMF conditions they typically separate from the dayside cusp ionosphere and propagate across the polar cap; often destabilizing along the way and producing radio scintillation. This work presents new high-resolution simulations of primary gradient-drift instability (GDI) in polar cap patches with the focus on understanding how these mesoscale features cascade to Fresnel scales responsible for scintillation. The GEMINI ionospheric model (https://github.com/gemini3d) is used to better understand the fundamental plasma instability physics occurring on small scales, as well as the geophysical importance of such structures (e.g., their influence on radio signals). Specifically, this work examines thermal effects (encapsulated in diamagnetic drifts, species diffusion across the background B-field, and temperature-sensitive chemical processes) on GDI progression, particularly in the nonlinear stage of the instability.

Presented by

Mark Redden

Institution

Embry-Riddle Aeronautical University

Keywords

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Off-Great-Circle Propagation in the Undisturbed Ionosphere and its Effect on OTHR

T. G. Cameron, R. A. D. Fiori, T. Thayaparan

Abstract

Over the Horizon Radar (OTHR) is a surveillance technique where High Frequency (HF) radio propagation is used to locate long range targets by utilizing the ionosphere as a reflecting surface. HF radio propagation is highly sensitive to ionospheric conditions; accurately determining a target’s position requires knowledge of the propagation paths used to reach the target. In the absence of localized electron density structures such as polar cap patches, HF radio propagation is assumed to follow an on-great-circle propagation path. In this study, off-great-circle propagation in an undisturbed ionosphere is investigated with a high latitude ionosphere model (E-CHAIM), a numerical ray-tracer, and data from an HF transmitter network. Large-scale east-west ionospheric gradients in the morning and evening sectors are shown to deflect northward directed HF radio waves by up to 15°. The implication for both OTHR operation, and for OTHR frequency and look angle determination is considered.

Presented by

Taylor Cameron

Institution

Natural Resources Canada

Keywords

HF Radio, OTHR

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Available June 24, 15:30-17:00 MDT

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▼ ITIT Back to top

Diego Yupanqui (1,2), Marco Milla (1), Karim Kuyeng (1), Eladio Ocaña (2) and Ernesto Oré (2)

Abstract

In this work, we are conducting a comparison of different methods to solve a one-dimensional aperture-synthesis radar imaging problem based on simulations. For this purpose, we are going to consider the geometry of the Jicamarca ionospheric radar. These methods are going to be applied to the generation of images of field-aligned plasma irregularities in the equatorial ionosphere, particularly, to the case of Spread-F phenomena. The methods used in the comparison goes from a direct Fourier inversion and a simple numerical integration, to more elaborated algorithms, such as, Capon’s method and Maximum entropy method. We are also going to include in the comparison, the compressed sensing technique using the Haar and dab4 basis, in this case, we are assuming that the brightness function of the spread-F echoes has a sparse representation. In the simulations of the radar measurements, we are considering Gaussian shape brightness functions. The different methods will be compared based on some metrics of the reconstructed images.

Presented by

Diego Yupanqui <diego.yupanqui@jro.igp.gob.pe>

Institution

(1) Radio Observatorio de Jicamarca, Instituto Geofísico del Perú, Lima, Perú, (2) Universidad Nacional de Ingeniería, Lima, Perú

Keywords

Radar imaging, inverse problem, Spread-F, compressed sensing, wavelets

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Available June 24th 3:30pm - 5:00pm Mountain Time (MT)

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ITIT11: Ionosphere-Thermosphere Response to Pronounced High-Speed Streams observed by Ocean-Based TEC receivers and Swarm-C

Federico Gasperini, Irfan Azeem, and Geoff Crowley

Abstract

In the declining phase of the solar cycle the polar coronal holes on the Sun expand and form non-axisymmetric extensions toward the equator. These extensions enhance the occurrence of high-speed solar wind streams (HSS) and related co-rotating interaction regions (CIR) in the low-latitude heliosphere, and cause moderate, recurrent geomagnetic activity affecting the ionosphere and thermosphere (IT). A combination of Vertical Total Electron Content (VTEC) measurements from two equatorial Global Positioning System (GPS) receivers hosted on ocean surface buoys, dawn and dusk total mass density observations from the Swarm-C satellite near 460 km, and output from the Whole Atmosphere Community Climate Model with thermosphere and ionosphere eXtension (WACCM-X) reveal the impact of prominent quasi-9-day recurrent geomagnetic activity driven by three sequences of HSS/CIR events during December 2018 - February 2019. Satellite and terrestrial observations indicate a significant response in thermospheric neutral density and equatorial TEC associated with these HSS/CIR events. The maximum TEC and neutral density response is found to persist for several days after the onset of the activity. The results suggest that CIR/HSS events can have significant effects on the IT for several days after the CIR has ended, with effects that during solar minimum are comparable to those of coronal mass ejections (CME) events.

Presented by

Federico Gasperini

Institution

ASTRA LLC

Keywords

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Available June 24, 3:30-5:00 PM MDT

Plasma density irregularities associated with resonant Alfvén waves in the lower auroral ionosphere

Hassan Akbari, Rob Pfaff, Jim Clemmons, Henry Freudenreich, Doug Rowland, Anatoly Streltsov

Abstract

During the 'Auroral Jets' experiment from Poker Flat, Alaska on March 2, 2017, two NASA sounding rockets were simultaneously launched into the active auroral ionosphere. The rockets were equipped with instrumentation to measure DC and AC electric fields, magnetic fields, energetic electrons, plasma density, and neutral winds and achieved apogees of 190 and 330 km. A prominent feature of the electric and magnetic field observations is the presence of localized, large-amplitude (±40 mV/m and ±100 nT), small-scale Alfvén wave structures at altitudes as low as 150 km in the vicinity of up- and down-ward current regions. We interpret the oscillations as representing standing waves associated with the ionospheric Alfvén resonator formed between the ionosphere and the lower magnetosphere. The electric field components of the Alfvén waves reveal signatures of wave steepening in correlation with electron precipitation and large variations of the background plasma density. The signatures are discussed in the context of nonlinear evolution of the ionospheric feedback instability associated with small-scale currents.

Presented by

Hassan Akbari

Institution

NASA GSFC, University of New Hampshire, Embry–Riddle Aeronautical University

Keywords

Abstract

The airglow acts as a display of processes in the thermosphere-ionosphere system. By detection of the airglow intensities, it is possible to monitor the variations of constituents' densities in various altitudes. For this purpose, we have started AMON (Airglow MONitoring) program in Slovakia, Central Europe. The program consists of a multi-wavelength all-sky airglow camera, a network of high sensitive photometers, and a GNSS receiver for the detection of ionospheric parameters. To identify the sources of detected variations, we employed advanced machine learning techniques to extract needed information from publicly available solar, space weather, and atmospheric data. The main highlights of the AMON program will be presented in the form of a poster.

Presented by

Simon Mackovjak

Institution

[1] Slovak Academy of Sciences (SK), [2] Technical University of Košice (SK), [3] Vihorlat Observatory (SK), [4] University of Turin (IT), [5] Charles University (CZ)

Keywords

airglow, machine learning

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Available during whole CEDAR workshop

Understanding the neutral wave characteristics in the daytime thermosphere using radio technique

Subir Mandal and Duggirala Pallamraju

Abstract

Knowledge of spatial and temporal characteristics of gravity waves (GWs) present in the thermosphere is crucial for a comprehensive understanding of the coupling between the different regions of the Earth’s atmosphere. However, the lack of conventional optical measurements limits such information, especially in the daytime. We have developed a new method to derive GW characteristics in the daytime thermosphere using digisonde measurements. We have analyzed two years of data over a low-latitude location, Ahmedabad, India. By monitoring the height variations of multiple isoelectron density contours, it is noted that, on occasions, downward phase propagation is seen (upward propagation of GWs). Such downward phase propagation and the presence of a common period (phase offsets caused by a common source) have been used to ascertain GW activity. We estimate vertical phase speeds and wavelengths of these GWs. Using such methodology, new and insightful results on the daytime upper atmospheric wave dynamics have been obtained, e.g.,: i) vertical propagation of GWs is present in only 41% of days, ii) vertical scale sizes, propagation speeds, and number of GWs present in the daytime thermosphere increase with solar flux, and iii) vertical propagation of GWs shows seasonal variation with maxima in equinoxes and minima in summers.

Presented by

Subir Mandal <subir@prl.res.in>

Institution

Physical Research Laboratory, Ahmedabad, India

Keywords

Gravity waves, Vertical propagation of gravity waves, daytime thermosphere, digisonde, isoelectron density contours

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Available Time: 15:30-17:00 MDT ; Dates: 22, 23, and 24 June 2021;

Evaluating Multi-Satellite Density Consistencies to Improve Gas-Surface Interaction Modeling in Helium-Rich Atmospheres

Valerie Bernstein, Marcin Pilinski, Timothy Minton

Abstract

Both laboratory experiments and satellite measurements indicate that Low Earth Orbit gas-surface interactions may change based on the incident angle and mass of impinging particles. Most widely-used drag coefficient models do not fully incorporate these dependencies. As such, existing drag coefficient model errors may be altitude dependent, with greater errors at higher altitudes near the oxygen-to-helium transition region. This can lead to biases in orbit-derived density datasets and models. We investigate multi-satellite density consistencies to infer how drag coefficient models can be improved in helium-rich atmospheric regimes. In these comparisons, the satellites have different geometries in order to evaluate the consistency of gas-surface interaction assumptions associated with incident particle angle and mass. We provide theoretical and orbital data-driven evidence to support implementing quasi-specular gas-surface interaction modeling at higher, helium-rich altitudes.

Presented by

Valerie Bernstein <valerie.bernstein@colorado.edu>

Institution

University of Colorado Boulder, Department of Aerospace Engineering Sciences

Keywords

Thermosphere, density, aerodynamic drag

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Available June 24th, 3:30 - 5:00pm mountain time

▼ ITMA Back to top

Validation of multistatic meteor radar analysis using realistic mesospheric dynamics from UA-ICON model: Reliability of gradients and vertical velocities

Harikrishnan Charuvil Asokan, Jorge L. Chau, Juan Federico Conte, Raffaele Marino, Juha Vierinen, Gerd Baumgarten, Sebastian Borchert

Abstract

Specular meteor radars (SMRs) are a major ground-based instrument to study the mesosphere and the lower thermosphere (MLT) dynamics. The recently developed multistatic approach of SMRs allows maximising the number of measurements from different viewing angles, hence enabling the estimation of horizontal wind fields and their second-order statistics (power spectrum, momentum fluxes). We have installed the operational versions of these techniques in Germany, Peru and Argentina, called SIMONe (Spread-spectrum Interferometric Multistatic meteor radar Observing Network) systems. Here, we present a validation study of multistatic meteor radar analysis by using virtual radar systems on the upper-atmosphere extension of the ICOsahedral Non-hydrostatic (UA-ICON) general circulation model with a horizontal grid spacing of 5 km. This particular study is focusing on the estimates of gradients and vertical velocities with these multistatic systems.

Presented by

Harikrishnan Charuvil Asokan

Institution

Leibniz-Institute of Atmospheric Physics at the Rostock University, Kühlungsborn, Germany

Keywords

Meteor Radar, Mesosphere and lower thermosphere, vertical wind, vertical velocity, MLT

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Available June 24th 15:30 - 17:00pm Mountain Time (MT)

JRO digital receiver modernization using ADCs with high-speed JESD204B data interface and FPGAs

Joaquin Verastegui, John Rojas, Isaac Tupac, David Caceres, Luis Gonzales

Abstract

The latest data acquisition system running at the Jicamarca Radio Observatory for the main radar has been used for more than five years now. Although there are no major inconveniences on the performance there have been some problems with internal interferences which are usually unpredictable and related to the PCB design, the noise floor can be different between channels too. So there are some chances of improvement developing a new approach. We propose a new design based on a high-speed JESD204B data interface; the digital signal processing and custom acquisition logic will be implemented inside an FPGA capable of managing the JESD204B high-speed interface. This will give us the flexibility of implementing digital blocks inside the FPGA to improve the performance of the receivers, we will gain scalability to perform on a much higher bandwidth and the PCB will be very much simplified which will reduce the manufacturing costs, design time, and development time.

Presented by

JOAQUIN VERASTEGUI <jverastegui@igp.gob.pe>

Institution

Jicamarca Radio Observatory

Keywords

Acquisition System, FPGA, JESD204B, PCB design, HDL design.

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Available June 24th 15:30-17:00 MDT

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Modeling and Testing Petite-Ion Probe Instrument Performance for the KiNET-X Sounding Rocket Mission

Magdalina Moses, Kristina Lynch, Grace Kwon, Peter Delamere, Philip Erickson, Don Hampton, Shunrong Zhang

Abstract

The Kinetic-scale energy & momentum transport experiment (KiNET-X) will investigate kinetic-scale ionospheric plasma transport for a known input energy & momentum by measuring ionospheric perturbations from sounding rocket barium releases. The diagnostic payload carries 12 Petite-Ion Probes (PIPs). Four PIP pairs are part of the rocket’s main payload. Two instrument packages (Bobs) deployed in flight each carry two PIPs, one viewing in the ram direction and one looking out the side. PIPs determine plasma parameters by using a swept screen voltage to select energies of ions entering the detector. PIP gain choice is critical to observe the ionosphere which KiNET-X perturbes, so we modeled PIP observations for various gains over the predicted rocket trajectory through model ionospheres (IRI & ISRIM). Ultimately, we set the Bobs’ ram-looking PIP gain at 40mV/nA and side PIP gain at 330mV/nA. We lowered the gains of two PIP pairs on the main payload to 40mV/nA, leaving the rest at 320mV/nA.

Presented by

Magdalina Moses

Institution

Dartmouth College, Department of Physics and Astronomy

Keywords

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Available June 24 3:30-5 PM

Development of JROMAG-M103 Magnetometer for geomagnetism studies in Peru

Ricardo Rojas, Oscar Veliz

Abstract

Since 2007 a three-axis fluxgate magnetometer has been in development and under continuous improvement at Jicamarca Radio Observatory of the Geophysical Institute of Peru. It is based on the Fluxgate Mag-03 magnetic detector by Bartington Instruments. The JROMAG-M103 was developed to meet specific requirements of sensitivity, resolution, robustness, among others. This magnetometer, called JROMAG-M103, is being used in several geomagnetic monitoring networks, from different research institutions in South America. This poster presents the design aspects and technical specifications of the magnetometer and introduces further improvements that will be included in future versions.

Presented by

Oscar Veliz <oveliz@igp.gob.pe>

Institution

Instituto Geofisico del Peru

Keywords

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Available June 25th 9-11 am PET

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A Multi Tracer Analysis to Study the Chemical Composition Changes associated with the 2019 Sudden Stratospheric Warming Dynamics using SOFIE Observations

Saswati Das, Brentha Thurairajah, Scott M. Bailey

Abstract

The Arctic winter of 2019 observed by the Solar Occultation for Ice Experiment (SOFIE) indicates a strong descent of air rich in Nitric Oxide (NO) but with poor concentrations of Water (H2O) and Methane (CH4) from the lower - thermosphere to the stratosphere. The Sudden Stratospheric Warming(SSW) that occurred on 2 January 2019 triggered the transport. We analyze this SSW-triggered occurrence by continuously tracking it from early January until the end of April 2019. The northern hemispheric dynamics show similarities to descents from 2004, 2006, 2009, and 2013. We study the NOx (NO + NO2) descent to the stratosphere, where it catalytically reacts with Ozone (O3) at these altitudes. We analyze the impact of the SSW event on the secondary daytime O3 layer in terms of spatial and temporal variation. Finally, using SOFIE observations for NO, H2O, and CH4, we calculate the 2019 descent rate and understand the dynamics and chemical composition changes triggered by the 2019 SSW event.

Presented by

Saswati Das

Institution

Virginia Polytechnic Institute and State University

Keywords

SOFIE, Sudden Stratospheric Warming, Atmospheric Transport, Secondary Ozone Maximum, Chemical Composition Changes

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Available June 24, 3:30 pm -5:00 pm, MT

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▼ LTVI Back to top

Analysis of ionospheric long-term trends sensitivity to factors involved in their estimation

Ana G. Elias, Blas F. de Haro Barbas, Bruno S. Zossi, Mariano Fagre, Zenon Saavedra, and Franco D. Medina

Abstract

Ionospheric long-term trend values can depend on several factors based on the estimation method. In the case of experimental data these factors can be filtering process, inappropriate selection of data, EUV proxy used, period analyzed, among many others. In the case of values obtained from modeling they can be quality of input parameters, models chosen for needed variables, and adequacy of model assumptions. A sensitivity analysis can give estimates of these factors effect since it is used to investigate how the variation in an “output” can be attributed to variations in the “input factors”. This work is a continuation of a previous work, where a sensitivity analysis of F2 layer trend values was partially made. We deepen this analysis and expand it to ionospheric conductivity and currents in an attempt to elucidate the joint roles of the anthropogenic effect and of the Earth's magnetic field secular variation: their magnitudes, their “competition”, and their possible interaction.

Presented by

Ana G. Elias

Institution

FACET, Universidad Nacional de Tucuman

Keywords

Ionosphere, long-term trends, geomagnetic secular variation, climate change

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Available June 22, 1 PM - 5 PM Mountain Time

The effects of volcano emissions on geocoronal hydrogen Balmer-alpha emission in the southern hemisphere

Arianna Ranabhat, Susan Nossal, L. Matthew Haffner, Olivia Barr, Edwin J. Mierkiewicz, Carey Woodward

Abstract

We are investigating how the solar cycle, a major source of natural variability in the upper atmosphere, affects atmospheric hydrogen Balmer-alpha emissions. The hydrogen emissions may also be affected by large scale volcano aerosols. Hydrogen in the upper thermosphere and exosphere is a byproduct of lower atmospheric chemical reactions of H2O, CH4, H2, OH, and CH2O [Brasseur and Solomon, 2005]; volcanoes can emit H20 into the stratosphere, potentially affecting these hydrogen emissions. We used data taken by the Wisconsin H-alpha Mapper Fabry-Perot interferometer (WHAM) stationed in Cerro Tololo, Chile, to measure atmospheric Balmer-alpha emission during the solar cycle. Using the Voigt-fit spectral fitting code, I found Balmer-alpha emission areas of data with dates coinciding with the Puyehue Cordón Caulle eruption in June 2011.

Presented by

Arianna Ranabhat

Institution

University of Wisconsin, Madison - Department of Physics

Keywords

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Available June 23, 3:30 - 5 PM

Investigation of the Variability in OI 630 nm Nightglow Emission over Low-latitude Thermosphere

Sovan Saha and Duggirala Pallamraju

Abstract

Airglow emissions act as good tracers to understand the behaviour of the altitudinal region from where they originate. High Throughput Imaging Echelle Spectrograph is used to observe OI 630 nm nightglow emissions over Mt Abu (16 Mag-N), which emanate from around 250 km altitude. A photochemical model has been developed by which we can estimate nighttime OI 630 nm emission (correlation with observed emission > 0.9) using measured electron density, as input. Various kind of emission variability like monotonic decrement in emissions after sunset, post-sunset emission enhancement, latitudinal emission variation, movement of plasma bubble signatures in the spectral image etc. have been observed during a period of five years of observation (2013 to 2017). Equatorial electrodynamics, neutral winds have been investigated to find the cause of such variations. Independent measurements from other instruments like digisonde, imager, have used to establish the results, will be discussed in detail.

Presented by

Sovan Saha

Institution

Physical Research Laboratory, Ahmedabad, India

Keywords

OI 630 nm nightglow, Thermospheric winds, Optical Spectrometer, Digisonde, OI 630 nm photochemical model, Ionosphere-thermosphere coupling

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Available June 22, 23, 24 15:30-16:30 MDT

Multidecadal hydrogen variability

Nossal, Mierkiewicz, L. Qian, Woodward, Haffner, McInerney, S. Solomon, H.-L. Liu, Ranabhat

Abstract

Ground-based Fabry-Perot observations of Balmer α emissions taken from Northern mid-latitudes span multiple solar cycles, facilitating investigation of decadal scale variations, including natural variability in the hydrogen response to solar geophysical changes. We will discuss the extended Northern hemisphere hydrogen emission data set in the context of hydrogen variability on shorter timescales, WACCM-X model simulations, future plans to extend the data set, and longer-term observations of hydrogen-containing molecules at altitudes below.

Presented by

Susan Nossal

Institution

University of Wisconsin, Department of Physics

Keywords

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▼ LTVM Back to top

MLT summer length defined by mean zonal wind features observed for more than one solar cycle at mid- and high-latitudes in the northern hemisphere.

Juliana Jaen¹, Toralf Renkwitz¹, Peter Hoffmann¹†, Maosheng He¹, Yosuke Yamazaki², Christoph Jacobi³, Chris Hall⁴, Masaki Tsutsumi⁵, Vivien Matthias⁶, Jorge L. Chau¹.

Yingfei Chen, Xinzhao Chu, Shunrong Zhang, Chihoko Y. Cullens, Zhibin Yu, Z. Xu, W. Huang, J. Jandreau, T. J. Immel and Arthur D. Richmond

Abstract

Following the discovery of thermosphere-ionosphere metal (TIMt) neutral layers in the 100–200 km (Chu et al., 2011), many more TIMt layers have been reported in the polar and low-latitude regions, most of which occurred irregularly. This study presents the first lidar observations of regular occurrence of mid-latitude thermosphere-ionosphere Na (TINa) layers over Boulder, Colorado. TINa layers up to 150 km detected by high-sensitivity Na lidar exhibit dusk and dawn layers with downward phase, which is consistent with the semidiurnal tidal phase. One or more layers occasionally appear around local midnight and are likely related to strong TIDs (Traveling Ionospheric Disturbance) observed in TEC (Total Electron Content). The increase in volume mixing ratio above the turning point of the Na density slope (~105–110 km) suggests that the dawn/dusk layer is produced in situ by neutralizing converged Na+ layers. These new discoveries will provide new insights into plasma-neutral coupling.

Presented by

Yingfei Chen

Institution

University of Colorado Boulder

Keywords

Midlatitude, Metal layers, Thermosphere-ionosphere Na (TINa), ICON Hough Mode Extension tidal winds, TIDs (Traveling Ionospheric Disturbance)

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Available June 22th 3:30-5 PM Mountain time

▼ METR Back to top

Meteoroid Orbit Determination from HPLA Radar Data

Jared Blanchard, Nicolas Lee, Sigrid Close

Abstract

HPLA Radars have revolutionized meteor science by increasing the accuracy of position and velocity measurements of meteoroids as they burn up in the atmosphere. A single position and velocity vector is sufficient information to fully determine orbital characteristics in a restricted two-body problem. This computation is essential to identify interstellar particles. However, various perturbations influence the meteor on its way to Earth, meaning we don't have the full story at the time of radar observation. In this work we model the effects of important perturbations on the orbital elements of observed meteoroids. We compare the uncertainties in our perturbation models with the uncertainties in the radar observations themselves, showing how many interstellar particles may be mistaken for sun-bound objects.

Presented by

Jared Blanchard

Institution

Stanford University, Department of Aeronautics and Astronautics

Keywords

Uncertainty Propagation, Meteors, Radar, Orbit Determination, Interstellar

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Available June 22, 3:30-5:00 PM MT

High-Resolution Simulation of Plasma Formation Around a Small Ablating Meteoroid

Trevor Hedges, Sigrid Close, Meers Oppenheim, Glenn Sugar

Abstract

Meteor plasma head echos are frequently observed by radar, but to meaningfully deduce meteoroid properties, a plasma density distribution must be assumed. 3D electrostatic particle-in-cell simulations are used to predict this density distribution, including the effects of background fields. Previous results by Sugar et al. (2019) demonstrate that fields can cause electron density variations of up to 10% in the near-meteoroid region. Recent computational advances enable larger domain sizes that extend farther from the meteoroid and mitigate boundary effects. In this poster, we present results with 1024 grid cells in each dimension, improving from 512 cells in previous simulations. The transition from meteor head to trail is more broadly resolved, along with asymmetries in the electron density profile that result from field interactions and become more pronounced farther from the meteoroid. The results will enable more physically accurate interpretation of meteor head echo radar results.

Presented by

Trevor Hedges

Institution

Stanford University, Boston University

Keywords

Meteoroid, Meteor, Ablation, Plasma, Atmosphere, Ionosphere

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Available June 22nd, 15:30-17:00 MT

▼ MITC Back to top

A Statistical Study on the Inner Magnetospheric Signatures of Subauroal Ion Drift (SAID) and Subauroral Polarization Streams (SAPS)

Abdelaziz Hussein, Toshi Nishimura, Phil Erickson, Bea Gallardo-Lacourt, Vassilis Angelopoulos

Abstract

Recently, a new type of optical emission in Earth’s upper atmosphere called Strong Thermal Emission Velocity Enhancement (STEVE) was observed and is found to be associated with narrow ion flows (1°-2° in latitude) called Subauroral Ion Drifts (SAID). SAID are a special case of wider (3°-5° in latitude) ion flows called Subauroral Polarization Streams (SAPS). To understand the atmospheric emission, we must explore the generation mechanism of SAID. We conducted a statistical study on the inner magnetospheric signatures of SAID and SAPS using NASA’s THEMIS and VAP to understand the plasma conditions producing the ion flows. We found 40 SAID events and 44 SAPS events using THEMIS, 57 SAPS events found using VAP. A superposed epoch analysis showed that both SAPS and SAID flow channels reside between the hot ion and electron flux boundaries. The separation between the hot ion and electron boundaries proved to be an important factor in determining the type of ion stream being produced

Presented by

Abdelaziz Hussein

Institution

Boston University, Center for Space Physics

Keywords

Subauroral Polarization Streams, Subauroral Ion Dirfts, SAPS, SAID, Strong Thermal Emission Velocity Enhancement, STEVE, Magnetosphere-ionosphere coupling

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Available June 22nd 15:30 - 17:00 MT

Reconstructing Sequence of events, timing, and hemispheric asymmetries associated with isolated substorms

Bhagyashree Waghule, Delores Knipp

Abstract

Substorms occur when Earth’s magnetosphere extracts energy from the solar wind and dissipates it. This manifests on the nightside as invisible current systems. The sudden appearance of the ionospheric current has been conceptualized as 'substorm current wedge (SCW)’ in a region of enhanced conductivity. In order to further understand this phenomena and its linkage to nightside FACs, a superposed epoch analysis is performed on AMPERE derived FACs during the substorm cycle. The analysis is based on a list of substorm onsets identified with magnetometer data from SuperMAG published by Ohtani and Gjerloev (2020). The substorms were segregated based on the AL index with limits on substorm intensity ranging from 300-800 nT. We selected 27 onset instances within 2 weeks of equinoxes between 2011 and 2017 to minimize seasonal asymmetry. We will demonstrate hemispheric asymmetries in the FACs, time lags after substorm onset, and the variability of the Region 1 and Region 2 currents in the SCW.

Presented by

Bhagyashree Waghule <bhagyashree.waghule@colorado.edu>

Institution

University of Colorado Boulder

Keywords

Substorm, Field Aligned Currents, Ionosphere, Magnetosphere, Data Visualization

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Available June 22, 2021 from 3.30 PM to 5 PM MT

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The Influence of Whistler Mode Chorus Waves on Diffuse Electron Aurora and Ionospheric Conductance

Dillon Gillespie, Hyunju K Connor, Qianli Ma, Xiao-chen Shen, Doğacan S. Öztürk, Xiao-Jia Zhang

Abstract

Aurora precipitation is the second major energy source after solar irradiation that ionizes the Earth’s upper atmosphere. Diffuse electron aurora caused by the wave – particle interaction in the inner magnetopause waves takes over 60% of total auroral energy flux, strongly contributing to the ionospheric conductance and thus to the ionosphere – thermosphere dynamics. This poster quantifies the impact of Chorus waves on the diffuse electron aurora and the ionospheric conductance during quiet, medium, and strong geomagnetic activities. We derive the energy spectrum of diffuse electron aurora directly from the THEMIS wave statistics and inner-magnetosphere plasma conditions under a quasi-linear theory. Then, we calculate the height-integrated conductance from the wave-driven aurora spectrum using an electron impact ionization model of Fang et al. [2010] and the MSIS thermosphere model. Finally, we compare our results to the Ovation Prime aurora precipitation/conductance model.

Presented by

Dillon Gillespie <dmgillespie@alaska.edu>

Institution

University of Alaska, Fairbanks, AK; University of California Los Angeles, Boston University

Keywords

Space Physics, Magnetosphere-Ionosphere-Thermosphere coupling, Diffuse Aurora Precipitation, Chorus waves, Ionospheric Conductance

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Available June 22, 3:30pm-5:00pm MDT

Polar cap plasma transport during geomagnetic superstorm

Dimitry Pokhotelov, Isabel Fernandez-Gomez, Claudia Borries

Abstract

Positive plasma anomalies appear during the main phase of geomagnetic storms at (sub)auroral latitudes, extending across the polar cap as tongue of ionisation (TOI). Physical mechanisms of TOI, including electrodynamic plasma transport and neutral wind forcing, are simulated with TIE-GCM during the superstorm of Nov. 2003. The simulations are compared with TEC observations and GNSS tomography. The electrodynamic transport (vertical ExB component in particular) is identified as the main mechanism controlling TOI anomaly during great storms (Dst < -300 nT). This makes the choice of high-latitude convection model critical for simulations.

Presented by

Dimitry Pokhotelov

Institution

Institute for Solar-Terrestrial Physics at German Aerospace Centre (DLR)

Keywords

Polar cap, geomagnetic storm, plasma convection

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Available Tues 15:30 - 17:00

Antarctic SuperDARN Observations of Medium Scale Traveling Ionospheric Disturbances

Francis Tholley (1), Nathaniel Frissell (1), Joseph B. H. Baker (2), J. Michael Ruohoniemi (2), William Bristow (3)

Abstract

Medium Scale Traveling Ionospheric Disturbances (MSTIDs) are quasi-periodic variations of the F-region ionosphere with periods of 15 to 60 minutes and horizontal wavelengths of a few hundred kilometers. MSTIDs are typically associated with atmospheric gravity waves (AGWs). Statistical studies of MSTIDs using Super Dual Auroral Radar Network (SuperDARN) radars in the Northern Hemisphere have shown strong correlation with Polar Vortex activity, while a study of MSTIDs using the Antarctic Falkland Islands SuperDARN radar showed populations of MSTIDs with signatures suggestive of both solar wind‐magnetosphere coupling sources and lower neutral atmospheric winds sources. The sources of the MSTIDs are still not well understood, and there are limited studies of MSTIDs using SuperDARN radars in the Southern Hemisphere. We present initial results of MSTID observations of using Antarctic SuperDARN radars, including the radar at McMurdo Station.

Presented by

Francis Tholley

Institution

University of Scranton

Keywords

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Available June 22 5:30 PM - 7:00 PM EST

Watch Presentation

A Multi-Resolution Data Assimilation Model for High-Latitude Electric Fields

Haonan Wu, Xian Lu

Abstract

High-latitude ionospheric electric field modeling has long been investigated, among which the best-known technique is SuperDARN spherical harmonic fitting (SHF). Here we propose a new data assimilation framework to retrieve electric potential over the polar region using SuperDARN line-of-sight (LOS) ion drifts and certain background electric potential models. This new technique is based on a multi-resolution Gaussian process model (Nychka et al., 2015) and use the curl-free condition of electric field to extend the application from scalar to vector. Our tests indicate that the model has the capability of simulating both the global and local electric field. The fitting error decreases with increasing resolutions which means that more information in the input data is captured with more basis functions. We further perform a multi-level basis function testing case and the result shows that with appropriate setup of the basis functions, the model can even simulate the input field better with reducing computing burden. Our fitting results also show conformity with total electron content (TEC) measurements.

Presented by

Haonan Wu <haonanw@g.clemson.edu>

Institution

Clemson University

Keywords

Data Assimilation, IT Coupling, Electric Field

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Available Jun 22, 23 3:30-5pm, MST

FAC Contributions from Hall Conductance Gradients in Non-Sheet-Like Auroral Arcs

Jules van Irsel, Edward W. McManus, Meghan Burleigh, Kristina A. Lynch, Matthew D. Zettergren

Abstract

A horizontal slice of FAC in the auroral ionosphere is fed by perp. flow shear as well as gradients in Pedersen and Hall conductances (Eq. 6.12 in Kelley, 2009), yet for sheet-like arcs the Hall term is often ignored. This is because only the along-arc component of the Hall conductance gradient contributes to the FAC and for sheet-like arcs the gradients are across-arc. We look at the limitations of this assumption by using fluid-electrodynamic model runs provided by GEMINI (Zettergren & Semeter, 2012) with along-arc structure as well as E-W motion. We investigate arcs with a steep bend which can provide enough disturbance in both the E field and Hall conductance gradient directions for the Hall term in Eq. 6.12 to become non-negligible. Also, WTSs contain a trailing ionospheric density signature which alters the conductivities such that the Hall conductance gradients can also no longer be ignored. This added FAC makes up a non-sheet like structure which may be a feature in WTSs.

Presented by

Jules van Irsel

Institution

Dartmouth College

Keywords

Field-aligned current, Hall conductance, Westward traveling surge

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Available June 23 ,2021 17:45 - 19:00 EDT

Investigating Ionosphere-Thermosphere Coupling in the Nightside Auroral Oval

Katherine Davidson, Ying Zou, Mark Conde, Roger Varney, Stephen Mende

Abstract

Ionosphere-Thermosphere coupling is an important mechanism for dissipating the large amount of energy deposited into the high-latitude ionosphere from the magnetosphere. During periods of high geomagnetic activity, a convective electric field causes sudden changes in plasma velocity, which drives neutral winds through ion-neutral collisions. Thermospheric winds are known to follow, but generally lag behind and exhibit a velocity much smaller than the ionospheric convection. Therefore, in the current study we investigate ion-neutral coupling as a function of geomagnetic activity levels by using PFISR and SDI data for ion velocity and neutral wind velocity. Event selection requires clear sky conditions and exhibits a sudden change in ion velocity. The time and magnitude of the neutral wind response to changes in ion velocity are compared to the SYM-H and AE index of those events, which gives a measure of the ion-neutral coupling efficiency as a function of geomagnetic activity.

Presented by

Katherine Davidson

Institution

Department of Space Science, The University of Alabama in Huntsville, Huntsville, AL, USA

Keywords

IT Coupling

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Available June 22nd 3:30pm - 5:00pm

Probing the Density Profile of the Thermosphere Using Loss Cone Measurements

L. A. Davis and J. H. Clemmons

Abstract

A novel method for remotely sensing thermospheric parameters and the response of the high-latitude thermosphere to differing levels of solar and geomagnetic activity will be presented and discussed. This method utilizes the loss cone structure formed from charged particles precipitating onto the upper atmosphere to probe thermospheric density as a function of altitude. The dependence of the loss cone structure on incident particle energy can be mapped to different mirror point altitudes, thus yielding an altitudinal profile of the thermosphere. The principles of this method are illustrated by employing models for the thermosphere, the magnetic field near Earth, and the precipitating particle distributions. Density profiles calculated using this method for different periods of a modeled geomagnetic storm are shown and demonstrate new insights into the high-latitude thermosphere this method could provide. This method is explored in further detail using particle distribution measurements gathered by the Fast Auroral Snapshot Explorer (FAST) mission.

Presented by

Lance Davis

Institution

University of New Hampshire

Keywords

Loss Cone, FAST, Thermosphere, Density, Profile, Coupling, Novel, Method

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Available June 22nd, 3:30pm - 5:00pm Mountain Time (MT)

Watch Presentation

Overview and Simulations of the KiNET-X Sounding Rocket Mission

Nathan P Barnes, Peter A Delamere, Peter A Damiano, Drew A Coffin, Donald L Hampton, Mark Conde, Robert F Pfaff, Kristina A Lynch, Marc Lessard, Robert Michell, Miguel Folkmar Larsen

Abstract

We summarize an active plasma barium release experiment, KiNET-X, that will test our understanding of energy and momentum coupling at kinetic scales. KiNET-X is motivated by the unexpected cross-field "skidding" result of the Combined Release and Radiation Effects Satellite (CRRES) ionospheric barium release experiments [Delamere et al., 2000]. Other past active plasma experiments (e.g., APEX North Star [Pfaff et al., 2004]) showed the presence of parallel electric fields that are believed to facilitate this effect, however KiNET-X is the first to include both multipoint in-situ measurements in the Alfven wing and high resolution ground based optical observations. Using KiNET-X combined with computer modeling we seek to understand: 1) how momentum transport is affected by ion kinetic-scale physics, 2) how electromagnetic energy is converted into plasma kinetic and thermal energy, 3) the interplay between fluid- and kinetic-scales, and 4) how electrons are energized during the pickup process.

Presented by

Nathan Barnes

Institution

University of Alaska Fairbanks

Keywords

KiNET-X

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Available June 22 at 3:30 EDT

Yu Hong1, Yue Deng1, Qingyu Zhu2, Astrid Maute2, Delores J. Knipp2,3, Cheng Sheng1, Daniel Welling1, Ramon Lopez1

Abstract

Jackson Jandreau, Xinzhao Chu

Abstract

This study explores a recently developed method for removing photon noise from second-order lidar measurements, the interleaved method. The development of this method was driven by attempting to push parameters of daytime lidar measurements to higher altitudes, and the need to avoid the bias of noise in these higher-order measurements. Successfully doing so will expand the usability of lidar datasets considerably, opening up the door to more detailed, comprehensive studies. Three methods, variance removal (VR), spectral proportion (SP), and interleaved (INT) are compared by using them to calculate potential energy density (Epm) from sets of lidar data taken from McMurdo Station in high and low-noise conditions (January and July, respectively). At higher altitudes in both conditions, VR is unable to derive the Epm accurately as it struggles with high-noise. INT performs similarly to SP in low-noise conditions, yet only INT can accurately derive Epm in the high-noise conditions, with forward model results supporting these observations.

Presented by

Jackson Jandreau <jackson.jandreau@colorado.edu>

Institution

CIRES, CU Boulder

Keywords

Lidar, gravity waves

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Available 3:30-5 PM Mountain time, Tuesday 6/22

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Mechanism Studies of Madden-Julian-Oscillation Coupling into the Mesosphere/Lower Thermosphere Tides using SABER, MERRA-2, and SD-WACCMX

Komal Kumari, Haonan Wu, Abigail Long, Xian Lu, and Jens Oberheide

Abstract

Tidal deconvolution of SABER temperature observations allows one to resolve intraseasonal (30-90-day) tidal variability that occurs as a response to the recurring Madden-Julian Oscillation (MJO) in tropical convection. In this study, we make effort for a better understanding of the physical causes of intraseasonal variability in the diurnal tides as a function of various locations of active-MJO events over the Indian and Pacific Ocean. A statistical analysis of SABER observations and SD-WACCMX simulations confirmed previously unverified model predictions of a 10-25% tidal modulation by the MJO in the MLT region. The tides largely respond to the MJO in the tropospheric (from MERRA-2) tidal forcing, and the tidal advection and gravity wave drag forcing in the MLT region. Filtering by tropospheric/stratospheric background winds is comparably less important. These findings have broader implications as tides can also couple variability on MJO timescales from the MLT region to the IT region.

Presented by

Komal Kumari

Institution

Clemson University

Keywords

Atmospheric Tides, Madden Julian Oscillation, SABER, SDWACCMX

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Exploring the Effects of Geomagnetic Storms in the Ionosphere Using Principal Component Analysis

Divyam Goel, Thomas J. Immel, Yen-Jung Wu, Brian Harding, Colin Triplett, Chihoko Cullens

Abstract

We are trying to explore the effects of geomagnetic storms in the Ionosphere using data from NASA’s GOLD mission. The instrument is in a geostationary orbit, positioned above the South Atlantic Anomaly. This orbit produces a geospatial-temporal dataset that provides a consistent view of one part of the Earth at different times. This allows us to compare storm time conditions with quiet time conditions. We look at the O/N2 column density ratio as a parameter to study the compositional perturbation of the ionosphere during geomagnetic storms. The quantity ‘O/N2’ is the ratio of atomic oxygen number density to molecular nitrogen number density. We decided to explore the spatial variation in the O/N2 column density ratio for April by doing principal component analysis. To understand the effect of the geomagnetic storm that happened on day 111 or 20th April of 2020, we removed the data from days 111 and 112. We observed that the plots for the first three principal components showed a significant difference, which meant that the geomagnetic storm contributed a significant amount of variation in April. This motivated us to explore how the weights of the principal components were changing over the entire month. The weights of the first principal component showed that the storm day had the greatest influence on the first principal component. We also noticed that the weights of the third principal component showed a 6-day periodic variation, which makes us suspect some modulation from a Quasi 6-Day wave.

Presented by

Divyam Goel <divyam123@berkeley.edu>

Institution

University of California Berkeley,Space Sciences Laboratory

Keywords

Geomagnetic Storms, O/N2, Principal Component Analysis, Quasi 6 Day Variation, GOLD mission

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Available June 22, 3:30pm - 5:00pm Mountain Time

Watch Presentation

Two-dimensional horizontal correlation functions in the MLT region estimated using multistatic specular meteor radar observations during the SIMONe 2018 campaign.

Facundo L. Poblet, Jorge L. Chau, J. Federico Conte and Harikrishnan Charuvil Asokan.

Abstract

The study of the mesosphere and lower thermosphere (MLT) dynamics presents great challenges. One of them, is trying to find a dominant theory that explains mesoscales variations. Recently, Vierinen et al. (2019) introduced the Wind field Correlation Function Inversion (WCFI) technique, that estimates spatial correlation functions (among other products) in the MLT, from multistatic specular meteor radar observations. WCFI retrieves six independent components of the velocity correlation tensor distributed in horizontal lags, either in the radial direction or in the East-West/North-South directions (two dimensions). Using the 2D correlation functions of the fluctuating wind, we can investigate the two-point correlations of vertical vorticity and horizontal divergence (Lindborg, 2007). These functions are of great significance since they can provide information on the relative importance of stratified turbulence and internal gravity waves to explain the observed spectra.

Presented by

Facundo Poblet <poblet@iap-kborn.de>

Institution

Leibniz Institute of Atmospheric Physics.

Keywords

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Available June 22 - 3:30pm-5:00pm (MT)

Variations of PMCs at McMurdo, Antarctica Derived from 10 Years of Lidar Observations

Arunima Prakash, Xinzhao Chu, Manuel Da Costa Lindo, Mattia Astarita, Jackson Jandreau, V. Lynn Harvey, Shikha Raizada

Abstract

This paper presents decadal variability of Polar Mesospheric Clouds (PMCs) observed by an Fe Lidar at McMurdo from Dec 2010 through Feb 2020. PMCs are important tracers to study the dynamics and photochemistry of the mesosphere. They are also indicators of climate change. Though averaged interannual PMC brightness over the 10 years lacks solar cycle signatures, the diurnal variability of brightness/altitude exhibits strong diurnal phases in the 1st five seasons (2010-2015) during the solar maximum period, but both diurnal and semidiurnal variations in the 2nd five seasons (2016-2020) during the solar minimum period. This paper investigates the dependence of diurnal variability of PMCs on different phases of the solar cycle as well as atmospheric tides. We also look into the impact of cold phase of the wave-induced temperature oscillations on PMC features. Lastly, we examine the roles of temperature, water vapor and meridional wind in PMC interannual, seasonal and diurnal variability.

Presented by

Arunima Prakash <arunima.prakash@colorado.edu>

Institution

University of Colorado, Boulder

Keywords

PMC, solar cycle, EPM

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Available June 24th 3:30pm to 5pm MST

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Measurements of the meridional advective acceleration and neutral wind forcing in the E-region during different geomagnetic activity

Rafael L.A. Mesquita, Stephen R. Kaeppler, Miguel F. Larsen, Roger Varney, Ashton Reimer, Robert F. Pfaff, Irfan Azeem, John D. Craven, and Mark Conde.

Abstract

Forcing of high-latitude E-region winds has been extensively studied in various scales. However, measurements of the advective acceleration in the upper atmosphere are sparse in previous studies because it is difficult to observe using traditional methods. In this study, we used sounding-rocket launches at Poker Flat Research Range to measure the meridional advective acceleration of the horizontal winds in different geomagnetic activity levels. These measurements occurred in Kp indices ranging from 0.3 (Super Soaker) to 4.3 (Auroral Jets). The Poker Flat Incoherent Scatter Radar (PFISR) was used to measure F-region plasma velocities and E-region electron densities, which we used to calculate the instantaneous Lorentz acceleration. Measurements from the Alaska magnetometer network and the global auroral indices were used to assess the geomagnetic levels on different scales. Winds measured in different geomagnetic activity levels were within the same range of magnitude below 110 km ($<$100 ms$^{-1}$). Above that altitude, winds increased with geomagnetic activity, peaking at $\sim$300 ms$^{-1}$ (Auroral Jets). The meridional advection and instantaneous Lorentz accelerations increased with geomagnetic activity and were mainly in the same direction. The analysis of the modified Coriolis parameter (Coriolis and centrifugal parameters minus the Hall drag) showed that in certain altitudes the winds have a tendency to either keep an air parcel in the acceleration channel or to turn equatorward in strong geomagnetic activity.

Presented by

Rafael Mesquita

Institution

Clemson University

Keywords

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Available June 24th, 18:00 to 18:30 ET

Observation of Wavelike Oscillations in High-Latitude Thermospheric Winds Using Scanning Doppler Imagers (SDI)

Rajan Itani, Mark Conde

Abstract

We have processed temperature and line-of-sight wind data from several all-sky imaging optical Doppler spectrometers in Alaska and Antarctica to extract signatures of wave oscillations. Wind and temperature oscillations were extracted using a simple high-pass filter, tuned to remove periods longer than ~1.5 hours. We find that some level of oscillatory (presumably wave) activity is frequently discernible in the line-of-sight wind and in Doppler temperature. Such activity was seen at all observing sites, and at both E-region and F-region heights. Wave activity in the F-region correlates strongly with auroral and magnetic activity. Observed wave signatures also correlate strongly between geographically nearby sites. Lomb-Scargle analysis was performed to identify the typical periods associated with these oscillations. F-region oscillations tend to appear generally monochromatic and manifest relatively long wave periods (~90 minute) whereas E-region waves have a broader spectrum that extends down to ~30 minute periods.

Presented by

Rajan Itani

Institution

Geophysical Institute, University of Alaska Fairbanks

Keywords

Polar Aeronomy, Thermosphere, Gravity Waves

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Available Thursday, June-24-2021 (15:30-17:00 Mountain Time)

The role of plasma convection in the formation of the polar cap density depletions

Victoriya Forsythe and Bharat Kunduri

Abstract

During the winter time of the solar minimum the F-region densities become extremely low, and in some exceptional cases the F-layer completely disappears. These F-region density depletions are particularly deep during geomagnetically quiet nights, when slow plasma convection creates polar holes, extending 100-1000 km in size, where the electron density is several orders of magnitude lower than the background values. Polar holes are believed to be formed during the periods of the very slow anti-sunward convection, when the plasma is trapped just poleward of the statistical auroral oval in the absence of any ionization sources. At the same time, fast convection with rapid vertical plasma transport has also been associated with the polar hole formation. Combining the electron density measurements from the Advanced Modular Incoherent Scatter Radar (AMISR) and Poker Flat ISR, the state of art variational data assimilation tool Ionospheric Data Assimilation Four-Dimensional (IDA4D), and the convection data from the Super Dual Auroral Radar Network (SuperDARN) array, the role of plasma convection in the polar hole formation and evolution is experimentally investigated in this project. The F-region plasma was traced back in time prior to the polar hole formation to analyze the favorable conditions for its depletion. The convection velocity magnitude, direction, configuration, solar zenith angle, and the total electron content along the plasma trace are analyzed. The latitudinal extend of the polar depletion shows its close connection to the main ionospheric trough, which was not previously reported.

Presented by

Victoriya Forsythe

Institution

Atmospheric and Space Technology Research Associates

Keywords

polar density depletions, polar holes, main ionospheric trough

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Available June 21, 3:00 – 4:00pm MDT

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Retrieval of Electron Density Profiles from Ionosonde Virtual Height Data

Victoriya V. Forsythe, Irfan Azeem, Ryan Blay, Geoff Crowley, Wanli Wu

Abstract

A new method is developed to retrieve electron density profiles from a raw virtual height ionosonde traces. A Kalman filter is used for the assimilative inversion scheme together with the newly developed data-driven vertical covariance model. The incoherent scatter radar measurements from Arecibo observatory are employed as the known truth to simulate the virtual height data. The results show that the data assimilative inversion technique accurately retrieves the vertical structure of the ionospheric density at the bottom side of the profile and reconstructs the vertical and temporal small-scale density variations. A comparison with the results obtained by the POLynomial ANalysis (POLAN) inversion algorithm is presented. The assimilative inversion systematically outperforms the accuracy of the POLAN algorithm, on average reducing the percent errors in the electron density by half. The simultaneous data ingestion is compared to the sequential assimilation of the virtual height data.

Presented by

Victoriya Forsythe

Institution

Atmospheric and Space Technology Research Associates

Keywords

Virtual Height Inversion, electron density profile, assimilation, Kalman filter

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Available June 22, 3-4 MCT

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500 Years of Great Auroral Storms

Delores Knipp, Valerie Bernstein, Kaiya Wahl, Hisashi Hayakawa

Abstract

We wanted to learn how often great storms occur. To do so we started with a list of great storms from Marcel Nicolet and did an extensive literature search. Our poster shows 14 events in the last 500 years with great low-latitude aurora visible to the unaided-eye equatorward of 30 magnetic latitude These events have occured~ every 40-60 years during the past 500 years. We provide a list of specifics and references.

Presented by

Delores Knipp

Institution

University of Colorado Boulder

Keywords

Auororal Storms, Red Aurora, Severe Space Weather

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Available Thursday, June 24 During poster session, any other time can be arranged via email

Watch Presentation

Identifying and quantifying drivers of upper atmospheric nitric oxide emissions using NARMAX methods

Eliott Nagar, Delores Knipp, Liam Kilcommons

Abstract

Presented by

Eliott Nagar <eliott.nagar@gmail.com>

Institution

Smead Aerospace Engineering Sciences, University of Colorado Boulder

Keywords

NARMAX - Nitric Oxide - Spaceweather

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Available June 24, 3:30 pm

Estimating Atmospheric Electron Precipitation from FIREBIRD-II CubeSat Observations

K. A. Duderstadt, C.-L. Huang, B. Blake, A. B. Crew, A. T. Johnson, I. M. Householder, D. M. Klumpar, D. R. Marsh, T. Raeder, J. G. Sample, M. Shumko, S. Smith, H. E. Spence, F. M. Vitt

Abstract

This presentation summarizes a series of studies that use the NSF Focused Investigations of Relativistic Electron Burst Intensity, Range, and Dynamics (FIREBIRD-II) CubeSats to estimate atmospheric electron precipitation. Comparisons between FIREBIRD-II and POES MEPED observations from 2015-2020 demonstrate the value of FIREBIRD-II high energy resolution in understanding spectral shape, the importance of instrument geometry in assessing variability at low flux, and the challenges of distinguishing precipitating versus trapped electrons. A statistical study of ratios of precipitating and trapped electrons as a function of energy, L-shell, and Kp during spacecraft conjunctions between the Van Allen Probes and the FIREBIRD-II from 2015-2019 provides an additional means of estimating atmospheric electron precipitation. The ultimate goal is to calculate atmospheric ionization profiles, enhancements of nitrogen oxides (NOx), and resulting reductions of ozone (O3) in the middle atmosphere using the CESM-WACCM global atmospheric model.

Presented by

Katharine Duderstadt <katharine.duderstadt@unh.edu>

Institution

The University of New Hampshire

Keywords

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Available June 24 15:30-17:00 (MT)

Effects of Solar Flares and Their Characteristics on sudden frequency deviations observed by SuperDARN HF radars

Shibaji Chakraborty1, Liying Qian2, J. Michael Ruohoniemi1, and Joseph Baker1

Abstract

Solar flare-driven HF absorption is a well-known impact of SWF, the occurrence of a frequency disturbance on radio wave signal traversing the lower ionosphere in the early stages of SWF, also known as Doppler Flash, is newly reported and not well understood. Some prior investigations have suggested two possible sources that might contribute to the manifestation of Doppler Flash: first, enhancements of plasma density in the D and lower E regions; second, the lowering of the reflection point in the F region. We investigated a solar flare event using first principals modeling and SuperDARN HF radar observations to understand the driving mechanisms of solar flare-driven Doppler flash. We found that change in F-region refractive index is the primary driver of the Doppler flash. In this study, we conduct combined model-data studies on multiple solar flare events observed across different SuperDARN HF radars to find out how flare characteristics and geophysical conditions impact Doppler Flash. In addition, we investigate the driving mechanism of the lowering effect of F-region reflection points using ISR data and first principals modeling.

Presented by

Shibaji Chakraborty

Institution

1Virginia Tech, Space@VT, ECE, Blacksburg, United States of America; 2High Altitude Observatory, NCAR, HAO

Keywords

Solar Flare Effect, Doppler Flash, HF Radar, SuperDARN, Shortwave Fadeout

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Available June 24th 5:30-7:00 EDT

Equatorial and Low Latitude Ionospheric Response to Corotating Interaction Region/High-speed streams-driven geomagnetic storms

Santos, S.P.M ; Cândido, C. M.N. ; Becker-Guedes, F.

Abstract

In this work, we investigate the Brazilian low-latitude ionospheric variability during the descending phase of the solar cycle 24. During this interval, we have observed the occurrence of geomagnetic storms associated with Corotating Interaction Regions, CIRs, and High-Speed Streams, HSSs. From these storms, it was noticed that ~33 % were moderate level. CIRs/HSSs-driven geomagnetic storms can affect the low latitude ionosphere in several ways. Since the Total Electron Content (TEC) is an excellent parameter to diagnose the ionosphere, a statistical study of VTEC and a comparison to its five quietest days (5QD) reference was performed. We observed VTEC deviation as high as 400 % especially during the recovery phase of the storm. Additionally, it was noticed that most cases of VTEC deviation occurred at local evening and pre-dawn.

Presented by

Stella Santos <stella.santos@inpe.br>

Institution

Instituto Nacional de Pesquisas Espaciais (INPE)

Keywords

Solar Physics, Ionosphere, HSSs, CIR, TEC

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Available June 24th 3:30-5 PM Mountain time

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The Impact of Solar Activity on Forecasting the Upper Atmosphere via Assimilation of Electron Density Data

Timothy Kodikara, Kefei Zhang, N. M. Pedatella, and Claudia Borries

Abstract

This poster is an extract from Kodikara et at., (2021; doi: 10.1029/2020SW002660). The study presents a comprehensive comparison of the impact of solar activity on forecasting the upper atmosphere through assimilation of radio occultation (RO)-derived electron density (Ne) into a physics-based model (TIE-GCM) using an ensemble Kalman filter (KF). Globally abundant RO-derived Ne offers one of the most promising means to test the effect of assimilation on the model forecasted state on a global scale. This study emphasizes the importance of understanding how the assimilation results vary with solar activity, which is one of the main drivers of thermosphere-ionosphere dynamics. This study validates the forecast states with independent RO-derived GRACE (Gravity Recovery and Climate Experiment mission) Ne data. The principal result of the study is that the agreement between forecast Ne and data is better during solar minimum than solar maximum. The results also show that the agreement between data and forecast is mostly better than that of the standalone TIE-GCM driven with observed geophysical indices. The results emphasize that TIE-GCM significantly underestimate Ne in altitudes below 250 km and the assimilation of Ne is not as effective in these lower altitudes as it is in higher altitudes. The results demonstrate that assimilation of Ne significantly impacts the neutral mass density estimates via the KF state vector—the impact is larger during solar maximum than solar minimum relative to a control case that does not assimilate Ne. The results are useful to explain the inherent model bias, to understand the limitations of the data, and to demonstrate the capability of the assimilation technique.

Presented by

Timothy Kodikara

Institution

Institute of Solar-Terrestrial Physics, German Aerospace Center, 17235 Neustrelitz, Germany; SPACE Research Centre, RMIT University, Melbourne, VIC, Australia; China University of Mining and Technology, China Xuzhou 221116; High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO, USA; COSMIC Program Office, University Corporation for Atmospheric Research, Boulder, CO, USA

Keywords

thermosphere, ionosphere, COSMIC, GRACE, electron density, data assimilation, forecasting, Kalman filter, TIE-GCM

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Available Unfortunately, I will not be available today as I’m sick.

2021 CEDAR Workshop Virtual Poster Session

CEDAR

Tracks

Lightning detection in radio spectrograms based on convolutional neural networks

Observing Non-Migrating Diurnal Tides from Geostationary Orbit with GOLD

COUP06: Tropical Ionosphere-Thermosphere Coupling via the Non-Migrating Diurnal Tide as Revealed by Satellite Observations and WACCM-X

Impacts of Spatially Varying Eddy Diffusion Coefficient in the Lower Thermosphere on the Ionosphere and Thermosphere using GITM - Sensitivity Study

Numerical study to uncover the driving mechanisms of the migrating diurnal tide day-to-day variability

Solar flare effects in the Earth’s magnetosphere

Global Responses of Gravity Waves and Zonal Mean Winds to the Madden-Julian Oscillation and the Latitudinal Dependence of Their Relations using MERRA-2

Volcano-Generated Ionospheric Disturbances: Comparison of GITM-R Simulation with GNSS Observation

Model for Acoustic Gravity wave Numerical Simulation in Planetary atmospheres

Thermospheric Traveling Atmospheric Disturbances in Austral Winter from GOCE and CHAMP

Southern Hemisphere Mid-latitude MLT Response to the 2019 Antarctic Sudden Stratospheric Warming: PW-Tide-GW interactions observed by meteor radars

Mid-latitude SuperDARN backscatter classification using ray-tracing and neural networks

Impact of Thermospheric Wind Data Assimilation on Thermospheric and Ionospheric weather using a coupled Whole Atmosphere Data Assimilation System

Assimilative Modeling of the Day-to-Day Variability of the Equatorial Electrojet and its Longitudinal Dependence Using Ground- and Space-Based Magnetometer Data

FAST TEAMS in situ measurements of plasma convection

Exploration of machine learning tools developed for the study of space weather and its impact on position approximation in GNSS systems

Enabling Statistical Analysis of the Main Ionospheric Trough with Computer Vision

Exploring Space Weather Events with SWx TREC’s Space Weather Data Portal

LightDA: A Modular Library for Data Assimilation

pysat Instrument for CHAIN network

Reprocessing of data from Fabry-Perot interferometers (FPI) belonging to the IGP network of optical instruments

Calibration of Swarm-E (e-POP) suprathermal electron imager (SEI) flux

Prediction of Geomagnetic Field Disturbances across Alaska using Machine Learned LSTM Neural Networks

Coupled Thermosphere-Ionosphere Modeling of Global Neutral Densities Using Assimilated COSMIC Radio Occultation Data

Spectra Analysis in Faraday/Double Pulse Experiment at Jicamarca Radio Observatory (JRO)

Ionospheric Electron Density Modeling with Machine Learning

Total Electron Content Map Completion Using Neural Networks

An undergraduate-to-graduate bridge program: Significant Opportunities in Atmospheric Research and Science (SOARS)

Creating opportunities for student training and citizen science using ScintPi

CROWDSOURCING IONOGRAM SCALING: A CITIZEN SCIENCE PROJECT

Resolving the Spatial/Temporal Ambiguity of the EIA and ETA Using a LEO CubeSat Swarm Configuration

Characteristics of Ionospheric Scintillation During Daytime

Revisiting Langevin modeling for ISR spectra: Numerical benchmarks and first results

Understanding the daily to monthly equatorial electrojet variability

Daytime electron density irregularities in the low latitude F region

Modeling ionograms with deep neural networks: Applications to foF2 forecasting

Diurnal and semidiurnal tides in the Mesosphere and Lower Thermosphere over the central coast of Peru

Estimation of ionospheric electron densities from 150 km echoes

Space weather effects on the Brazilian equatorial and low-latitude ionospheric Maximum Usable Frequency (MUF) during the Saint Patrick’s Day geomagnetic storm

Validation of IVM Ion Density from the COSMIC-2 Mission

Modeling Studies of the Morphology of Equatorial F-region Plasma Drifts

Thermospheric Winds Over Huancayo, Peru

Investigations of oxygen dayglow emission variability over low latitudes under the influence of equatorial electrodynamic processes

Equatorial Plasma Depletions Observed in 135.6 [nm] Airglow from High Earth Orbit

The relation between hmF2 and radio occultation scintillation amplitude index RO-S4 index observed using FORMOSAT-7/COSMIC-2

Plasma Bubble Growth Rates During the September 2017 Geomagnetic Storm

Raytracing simulation of HF radio wave propagation in Antarctic ionosphere

Time Lag between 2020 Geomagnetic Storms and Ionospheric Scintillation Detection

Spread F Prediction using Machine Learning

Spread-F occurrence during geomagnetic storms near the southern anomaly crest in South America

Machine Learning Prediction of Storm-time Ionospheric Irregularities from GNSS-derived ROTI maps

High-resolution Simulations of Primary Gradient Drift Instability in Polar Cap Patches

Off-Great-Circle Propagation in the Undisturbed Ionosphere and its Effect on OTHR

Deriving column-integrated thermospheric temperature with the N2 Lyman-Birge-Hopfield (2,0) band

Observations of Mid-latitude Irregularities Using the Oblique Ionosonde Sounding Mode for the HamSCI Personal Space Weather Station

Neutral Wind Instrumentation on the Dynamo 2 Sounding Rocket Mission

Radar imaging comparison methods

ITIT11: Ionosphere-Thermosphere Response to Pronounced High-Speed Streams observed by Ocean-Based TEC receivers and Swarm-C

Plasma density irregularities associated with resonant Alfvén waves in the lower auroral ionosphere

Using novel geospace sensor techniques to resolve high-latitude ionospheric plasma density structures and their solar drivers

Upgrade of the Automatic Beam Switching (ABS) at Jicamarca Radio Observatory (JRO)

Pursuit of Atmospheric Column O/N2 Measurements from EUV Dayglow

Airglow monitoring program in Central Europe

Understanding the neutral wave characteristics in the daytime thermosphere using radio technique

Evaluating Multi-Satellite Density Consistencies to Improve Gas-Surface Interaction Modeling in Helium-Rich Atmospheres

Validation of multistatic meteor radar analysis using realistic mesospheric dynamics from UA-ICON model: Reliability of gradients and vertical velocities

JRO digital receiver modernization using ADCs with high-speed JESD204B data interface and FPGAs

Modeling and Testing Petite-Ion Probe Instrument Performance for the KiNET-X Sounding Rocket Mission

Development of JROMAG-M103 Magnetometer for geomagnetism studies in Peru

A Multi Tracer Analysis to Study the Chemical Composition Changes associated with the 2019 Sudden Stratospheric Warming Dynamics using SOFIE Observations

Analysis of ionospheric long-term trends sensitivity to factors involved in their estimation

The effects of volcano emissions on geocoronal hydrogen Balmer-alpha emission in the southern hemisphere

Investigation of the Variability in OI 630 nm Nightglow Emission over Low-latitude Thermosphere

Multidecadal hydrogen variability

MLT summer length defined by mean zonal wind features observed for more than one solar cycle at mid- and high-latitudes in the northern hemisphere.

Observing Large Scale Traveling Ionospheric Disturbances using HamSCI Amateur Radio: Climatology with Connections to Geospace and Neutral Atmospheric Sources.

Tidal Signature in Sporadic E Occurrence Rate, Using GAIA Model and FORMOSAT-3/COSMIC Radio Occultation Data