CEDAR: Investigating the Mesosphere and Lower Thermosphere Neutral Temperature and Winds Responses to Geomagnetic Storms Equatorward of the Auroral Zone

The Mesosphere and Lower Thermosphere (MLT) serve as a conjunction area of well mixed neutral atmosphere and the ionosphere that is dominated by charged species. The project aims to uncover and understand the temperature and wind variations observed in middle and low latitude MLT during geomagnetic storms, which are one of the most active driving forces that decide space weather. By revealing the mechanism of the MLT variations during the geomagnetic storm, this work will determine the space weather conditions during various intensive geomagnetic storms. The results of this investigation will also advance the understanding of the coupling and energy transfer from upper thermosphere into MLT. The work is important because space weather can affect satellites, communications, navigation, and other technologies that support public safety, commerce, and security. The project will contribute to workforce development through training of an early career scientist and students in STEM fields. The approach is to conduct comprehensive numerical investigations of several intense geomagnetic storms, utilizing advanced atmospheric models, combined with resonance lidar temperature and winds measurements, the project will address: (a) the pattern of temperature and horizontal neutral wind variations in mid-latitude MLT during geomagnetic storms and understand the variations of the MLT responses to geomagnetic storms with different onset times, and (b) the mechanisms underlying the geomagnetic activity-induced MLT temperature and wind variations, especially in middle and low latitudes where storm-time direct Joule heating and ion drag are weak. More specifically, it will address the new aspect of ion-neutral coupling process, e.g. the impacts from the ionosphere (above) to the neutral MLT (below). The response of neutral atmosphere during geomagnetic disturbances in the MLT region has consequences on thermospheric gravity waves due to variations in the filtering in the lower thermosphere and also impacts ion-neutral coupling at MLT altitudes. Overall, the comprehensive investigation will advance the understanding of such complex interaction processes through the system science approach that covers both the electrodynamics and neutral dynamics in the upper atmosphere. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. NSF Award ID: 2528651 | Program: 01002627DB NSF RESEARCH & RELATED ACTIVIT | Principal Investigator: Tao Yuan | Institution: Utah State University, LOGAN, UT | Award Amount: $424,932 View on NSF Award Search: https://www.nsf.gov/awardsearch/show-award/?AWD_ID=2528651 View on Research.gov: https://www.research.gov/awardapi-service/v1/awards/2528651.html