2020 Virtual Summer Workshop

Virtual GEM Summer Workshop 2020

Due to the ongoing COVID-19 pandemic, the 2020 Summer GEM workshop was held virtually over Zoom and Slack. The Dayside Kinetic Processes in Global Solar Wind-Magnetosphere Interaction focus group held 2 concurrent sessions on Thursday between 1:00pm-2:30pm and 3:00pm-4:30pm ET. The sessions were well attended with a peak audience of 82 participants. Short summaries of the sessions are provided below.

Session 1: Thursday Concurrent Session 1 1:00pm-2:30pm ET

Daniel Graham (IRF Uppsala, Sweden) provided an overview of the MMS science being conducted by the IRF Uppsala team. A wide variety of topics were discussed such as magnetic reconnection, whistler generation at quasi-perpendicular shocks, bow shock ion reflection, and electrostatic waves at the magnetopause.

Chih-ping Wang (UCLA, USA) presented a THEMIS-DMSP conjunction event to show magnetospheric processes responsible for the variations of soft electron precipitation. As shown by the three THEMIS probes, the large precipitation variations observed by DMSP were contributed by strong spatial and temporal variations in the plasma sheet cold electron fluxes, waves of three different modes (kinetic Alfven waves, ECH, and chorus waves), and upward field-aligned currents.

Brian Walsh (Boston University, USA) discussed the upcoming LEXI mission designed to place an X-ray telescope on the lunar surface to generate images of the dayside magnetopause. The project is part of the NASA Lunar Surface and Technology Payloads (LSITP) program and is scheduled for lunar deployment in 2022

Hyunju Connor (University of Alaska Fairbanks, USA) estimated neutral densities near the subsolar magnetopause using XMM-Newton X-ray observations and OpenGGCM global MHD model. The estimated neutral densities are higher during solar minimum than solar maximum, suggesting that photoionization plays an important role in this outer exosphere region.

Martin Archer (Queen Mary University of London, UK) discussed parameterizing the steepening of foreshock ULF waves into shocklets and SLAMS. He introduced an independent and dimensionless quantitative measure of wave steepening based on the tail weight of dB/dt, showing this well orders the phenomena and correlates highly to ΔB/B allowing future quantitative comparisons of steepening under different upstream conditions and at different environments across the solar system.

Yuxi Chen, (University of Michigan, USA) presented the MHD-EPIC simulation results of the southward IMF challenge event, compared the simulation magnetic field and plasma properties with the MMS observations, and studied the evolution of the X-lines at the magnetopause.

Session 2: Thursday Concurrent Session 1 3:00pm-4:30pm ET

Hyomin Kim (New Jersey Institute of Technology, USA) presented ionospheric signatures at interhemispheric conjugate locations in response to hot flow anomalies (HFAs) observed by the MMS spacecraft near the bow shock. A series of HFA events occurred over the course of less than an hour, of which the ground responses were shown as traveling convection vortices (TCV), EMIC waves, and ionospheric convection flow changes/enhancements with approximately 8 min delays. Solar wind and geomagnetic activities did not appear to provide favorable conditions for such dynamic signatures on the ground.

Terry Liu (UCLA, USA) presented case studies that show that magnetosheath jet-driven bow waves can accelerate ions and electrons. From a statistical study, they showed that large solar wind dynamic pressure, large plasma beta (low magnetic pressure), and large Alfven Mach number favor the formation of jet-driven bow waves. They also showed that it is common for them to accelerate particles indicating their potential contribution to the particle acceleration at the parent shock.

David Sibeck (NASA/GSFC, USA) presented observations from a time interval when the THEMIS spacecraft straddled the post-noon bow shock. The observations confirm the direct transmission of correlated foreshock cavity density and magnetic field strength variations into the magnetosheath.

Sun-Hee Lee (NASA/GSFC, USA) used Magnetospheric Multiscale (MMS) spacecraft observations to identify 23 FBs from September 2015 to January 2020. Ion intensities at energies for 5.2 to 37.4 keV are generally greater during than before or after the events, suggesting that FBs can accelerate particles to these energies.

Ahmad Lalti, (IRF Uppsala, Sweden) presented in the generation of whistler waves upstream of quasi-perpendicular shocks.

Adam Michael (Applied Physics Laboratory, USA) discussed MMS observations of periodic low frequency waves at the dawn-flank, high-latitude boundary layer on February 25, 2016, likely generated by the Kelvin-Helmholtz instability. With the global MHD magnetosphere model, GAMERA, a reinvention of the high-heritage LFM code, they show that despite the pristine slow wind impacting the magnetosphere, the high-latitude boundary layer is unstable to KHI. The waves within the global MHD model are consistent with MMS observations and occur where the IMF direction causes the draped field to be perpendicular to the flow velocity.