Sept. 2, 2020, 3 -4 p.m.
"Global Integrated Modeling of Geospace Storms"
Speaker: Slava Merkin, Space Physicist at Johns Hopkins University Applied Physics Laboratory
Sept. 9, 2020, 3 - 4 p.m.
"Rediscovery of the Plasmasphere: History and Future of Plasmasphere Research"
Speaker: Jerry Goldstein, Space Physicist for the Southwest Research Institute/Adjoint Assistant Professor at the University of Texas - San Antonio
Sept. 16, 2020, 3 - 4 p.m.
Sept. 23, 2020, 3 - 4 p.m.
Sept. 30, 2020, 3 - 4 p.m.
"The Onset of Magnetic Reconnection in Earth’s Magnetotail"
Speaker: Kevin Genestreti, Senior Research Scientist for SwRI-EOS
Abstract: "The elongated tail of our night-side magnetosphere stores energy from the solar wind. The oppositely-directed magnetic fields in the northern and southern tail are separated by a current sheet, which often thins dramatically then “short circuits”. Microscopic (~107 km3) magnetic reconnection sites violently shred the thin current sheet, rapidly dissipating stored energy. To first order, the current sheet thickness is controlled by the balance of its internal proton thermal pressure and external magnetic pressure. Reconnection at the day-side magnetosphere drives global (~1015 km3) plasma convection, which may thin the current sheet by increasing its external pressure and/or depleting its internal pressure. However, tail reconnection does not necessarily follow day-side reconnection and some thin current sheets remain stable. Causal relationships between reconnection and the current sheet instabilities that often accompany it have been predicted but not verified. Here we report in-situ observations of the of the macroscopic forces that thinned the current sheet and the subsequent microscopic initiation of tail reconnection. We find that the tail current sheet thins by evacuating its thermal pressure without significant day-side reconnection. The solar wind prompts the pressure evacuation and, eventually, initiates reconnection by momentarily compressing the tail. Reconnection was initiated in multiple locations once the current sheet surpassed the threshold for the electron-tearing instability, which requires a sufficiently thin current sheet with a weak magnetic field and a low ion-to-electron temperature ratio. One reconnection site quickly engulfs the others, becoming the dominant region that shreds the tail’s magnetic field, fitting with simple models."
Oct. 7, 2020, 3 - 4 p.m.
"Understanding dynamical ring current and ionosphere coupling with the RCM"
Speaker: Frank Toffoletto, Professor of Physics and Astronomy at Rice University
Oct. 14, 2020, 3 - 4 p.m. in 301 Morse Hall
"Observation-Based Approaches to the Modelling of Magnetised CMEs in the Inner Heliosphere with EUHFORIA"
Speaker: Camilla Scolini, Post-Doctoral Researcher at the University of New Hampshire
Abstract: Coronal Mass Ejections (CMEs) are the primary source of strong space weather disturbances at Earth and other locations in the heliosphere. Understanding the physical processes involved in their formation at the Sun, propagation in the heliosphere, and impact on planetary bodies is therefore critical to improve current space weather predictions throughout the heliosphere. The capability of CMEs to drive strong space weather disturbances at Earth and other planetary and spacecraft locations primarily depends on their dynamic pressure, internal magnetic field strength, and magnetic field orientation at the impact location. In addition, phenomena such as the interaction with the solar wind and other solar transients along the way, or the pre-conditioning of interplanetary space due to the passage of previous CMEs, can significantly modify the properties of individual CMEs and alter their ultimate space weather impact. Investigating and modeling such phenomena via advanced physics-based heliospheric models is therefore crucial to improve the space weather prediction capabilities in relation to both single and complex CME events.
In this talk, we present our progress in developing novel methods to model CMEs in the inner heliosphere using the EUHFORIA MHD model in combination with remote-sensing solar observations. We discuss the various observational techniques that can be used to constrain the initial CME parameters for EUHFORIA simulations. We present current efforts in developing more realistic magnetised CME models aimed at describing their internal magnetic structure in a more realistic fashion. We show how the combination of these two approaches allows the investigation of CME propagation and evolution throughout the heliosphere to a higher level of detail, and results in significantly improved predictions of CME impact at Earth and other locations in the heliosphere. Finally, we discuss current limitations and future improvements in the context of studying space weather events throughout the heliosphere
October 21, 2020, 3 - 4 p.m.
"Our Next LEAP Forward In Studying Gamma Ray Bursts"
Speaker: Mark McConnell, UNH Professor of Physics and Director for SwRI-EOS
October 28, 2020, 3 - 4 p.m.
"Electromagnetic Ion Cyclotron Waves in the MMS Era: Wave Generation and Propagation"
Speaker: Sarah Vines, Space Physicist at the Johns Hopkins University Applied Physics Laboratory
Nov. 4, 2020, 3 - 4 p.m.
"Radial and Temporal Evolution of Stream Interaction Regions and Co-Rotating Interaction Regions"
Speaker: Robert Allen, Space Physicist at the Johns Hopkins University Applied Physics Laboratory
Nov. 18, 2020, 3 - 4 p.m.
"Super DARN Insights on Thermosphere-Ionosphere-Mesosphere Interactions"
Speaker: Michael Ruohoniemi, Professor of Electrical and Computer Engineering, Virginia Tech University
Nov. 25, 2020, 3 - 4 p.m.
Dec. 9, 2020, 3 - 4 p.m.