Research Highlights

Research Highlights

A selection of highlights culled from publications by HAO staff.

Synthetic Hα images generated from a MURaM simulation

Rapid Blue- and Red-shifted Excursions in H α line profiles synthesized from realistic 3D MHD simulations

S. Danilovic, J. P. Bjørgen, J. Leenaarts, and M. Rempel discuss the important role of Rapid blue- and red-shifted events (RBEs/RREs) in mass-loading and heating the solar corona, but their nature and origin are still debatable. They model these features to learn more about their properties, formation and origin.

Two flux surfaces pressed into contact

The topological nature of the Parker Magnetostatic Theorem

B. C. Low reviews the two-plate initial boundary-value problem of Parker, treating the relaxation of a 3D magnetic field prescribed with an arbitrary topology to a terminal force-free field in a cold, viscous, electrically perfect fluid-conductor. Anchored by their foot-points at the perfectly conducting rigid plates, the relaxing field preserves its topology.

neutral density perturbation observed by CHAMP and GRACE

Thermospheric Density Perturbations Produced by Traveling Atmospheric Disturbances during August 2005 Storm

K. H. Pham, W. Wang, H. Liu, D. Lin, M. Wiltberger, et al. discuss how during geomagnetic storms, increased activity within the geospace environment causes large scale plasma convection to occur and electrons to precipitate into the upper atmosphere. The enhanced heating of the thermosphere by the plasma convection and electron precipitation can produce large perturbations in the neutral density. 

ICON MIGHTI track

Pronounced suppression and X-pattern merging of equatorial ionization anomalies after the 2022 Tonga volcano eruption

Wenbin Wang, Liying Qian, et. al. investigate the crests variations and associated ionosphere-thermosphere disturbances following the 2022 Tonga Volcano eruption, dramatic suppression and deformation of the equatorial ionization anomaly (EIA) crests occurred in the American sector ∼14,000 km away from the epicenter.

Sunquake Detection Process Diagram

A Machine Learning Enhanced Approach for Automated Sunquake Detection in Acoustic Emission Maps

Vanessa Mercea, Alin Razvan Paraschiv, Daniela Adriana Lacatus, Anca Marginean, Diana Besliu-Ionescu  introduce an acoustic holography processed dataset constructed from egression-power maps of solar active regions for Solar Cycles 23 and 24. They then present a pedagogical approach to the application of machine learning representation methods for sunquake detection using AutoEncoders, Contrastive Learning, Object Detection and recurrent techniques, which we enhance by introducing several custom domain-specific data augmentation transformations.

TIEGCM vertical ExB drift

The Ionospheric Connection Explorer - Prime Mission Review

Astrid Maute et. al., following the two-year prime mission of the NASA Ionospheric Connection Explorer (ICON) mission collected a key set of in-situ and remote sensing measurements that are, by virtue of a detailed mission design, uniquely comparable, ICON provides for new investigations of the mechanisms that control the behavior of the ionosphere-thermosphere system under both geomagnetically quiet and active conditions.

WACCMX+DART analysis

The Impact of Assimilating COSMIC-2 Observations of Electron Density in WACCMX

N.M. Pedatella and J.L. Anderson present study investigates the impact of assimilating electron density profiles from the Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2) mission in a whole atmosphere data assimilation system. The observations are assimilated into the Whole Atmosphere Community Climate Model with thermosphere-ionosphere eXtension (WACCMX) using the Data Assimilation Research Testbed (DART) ensemble adjustment Kalman filter.

Global-scale Observation of Limb and Disk observed

Hemispherically Asymmetric Evolution of Nighttime Ionospheric Equatorial Ionization Anomaly in the American Longitude Sector

Xuguang Cai, Liying Qian, Wenbin Wang, Joseph M. McInerney, Han-Li Liu, Richard W. Eastes in JGR–Space Physics reveal that the Global-scale Observation of Limb and Disk (GOLD) mission observed distinct post-sunset, hemispherically asymmetric evolution of the equatorial ionization anomaly between 40° and 50°W on 19 November 2018, with the southern crest shifting poleward but the northern crest remaining in the same latitude region. The Whole Atmosphere Community Climate Model-eXtended captured this phenomenon.

Diurnal and zonal mean ITEC from (a) COSMIC-2 observations

Ionosphere Variability During the 2020-2021 SSW: COSMIC-2 Observations and WACCM-X Simulations

Nicholas Pedatella investigates the variability in the ionosphere during the 2020-2021 sudden stratospheric warming (SSW) using a combination of Constellation Observing System for Meteorology, Ionosphere, and Climate-2 (COSMIC-2) observations and Whole Atmosphere Community Climate Model with thermosphere-ionosphere eXtension (WACCM-X) simulations. The unprecedented spatial-temporal sampling of the low latitude ionosphere afforded by COSMIC-2 enables investigating the short-term ($<$ 5 days) variability in the ionosphere during the SSW event