Wednesday, April 12, 2023 - 3:10 p.m. to 4:10 p.m.
Morse Hall rm 301 -OR- Zoom
Two Speakers/Two topics: Jenna Burget and Tyler Metivier – UNH graduate students
Title (Jenna): "Investigating High Altitude Neutral Upwelling in the Cusp"
Abstract: The SCIFER-2 sounding rocket launched from Svalbard, Norway on January 18, 2008. It reached an apogee of approximately 1500 km and flew above Poleward Moving Auroral Forms (PMAFs). Results from the rocket’s Ultraviolet Photometer (UV-PMT) showed neutral density enhancements during flight at unexpectedly high altitudes, half of which have been found to coincide with PMAFs. The UV-PMT was designed to observe the density of neutrals by measuring the brightness of neutral atomic oxygen. This unexpected result of neutral upwelling at high altitudes was replicated by the Sadler and Otto model, which uses precipitating electrons typical for PMAFs to predict changes in vertical particle density. Both measurements from SCIFER-2 and the Sadler and Otto model have shown neutral density enhancements at high altitudes along with precipitating electrons. This suggests a connection between Type 2 ion upflow, caused by precipitating electrons, and the upwelling of neutrals. To investigate this further, more measurements will be taken with a similar UV-PMT on the 3U Cubed satellite. This CubeSat is being developed by University of New Hampshire, Sonoma State University, and Howard University as part of the IMAP Student Collaboration
Title (Tyler): "Contrasting Dipolarization Front Structure and Dynamics with MMS"
Abstract: Dipolarization fronts (DF) are localized magnetic boundaries in the magnetotail that separate the downstream energetic particles in the nightside magnetosphere from the ambient plasma. They are characterized by a sharp, positive gradient in the northward magnetic field component and play an important role in energy transfer and conversion in the magnetosphere. The Magnetospheric Multiscale (MMS) mission has orbited during a wide variety of interplanetary conditions, including: quiet periods of slow solar wind, fast solar wind with large-amplitude Alfvénic fluctuations, and magnetospheric substorm and storm events. We describe a numerical algorithm, with which we’ve found hundreds of DFs during the 2018 MMS tail season in both the near-Earth tail (XGSM = -25 to -9 RE) as well as the inner magnetosphere (XGSM >-9 RE). We present properties of these DFs, relate them to the interplanetary conditions and describe our progress in categorizing them.
Schedule: Check out the rest of this season's Space Science Seminar Series, as well as previous recordings.
