Energy Deposition by Mesoscale High‐Latitude Electric Fields Into the Thermosphere During the 26 October 2019 Geomagnetic Storm. Issue 12 (23rd December 2022)

• Record Type: Journal Article
• Authors: Meng, Xing; Ozturk, Dogacan S.; Verkhoglyadova, Olga P.; Varney, Roger H.; Reimer, Ashton S.; Semeter, Joshua L.; Kaeppler, Stephen R.; Zhan, Weijia
• Is Part Of: Journal of geophysical research. Volume 127:Issue 12(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-12-23
• Subjects: Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1029/2022JA030716
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: Mesoscale high‐latitude electric fields are known to deposit energy into the ionospheric and thermospheric system, yet the energy deposition process is not fully understood. We conduct a case study to quantify the energy deposition from mesoscale high‐latitude electric fields to the thermosphere. For the investigation, we obtain the high‐latitude electric field with mesoscale variabilities from Poker Flat Incoherent Scatter Radar measurements during a moderate geomagnetic storm, providing the driver for the Global Ionosphere and Thermosphere Model (GITM) via the High‐latitude Input for Mesoscale Electrodynamics framework. The HIME‐GITM simulation is compared with GITM simulations driven by the large‐scale electric field from the Weimer model. Our modeling results indicate that the mesoscale electric field modifies the thermospheric energy budget primarily through enhancing the Joule heating. Specifically, in the local high‐latitude region of interest, the mesoscale electric field enhances the Joule heating by up to five times. The resulting neutral temperature enhancement can reach up to 50 K above 200 km altitude. Significant increase in the neutral density above 250 km altitude and in the neutral wind speed are found in the local region as well, lagging a few minutes after the Joule heating enhancement. We demonstrate that the energy deposited by the mesoscale electric field transfers primarily to the gravitational potential energy in the thermosphere. Plain Language Summary: The high‐latitude region of the terrestrial upper atmosphere is an important pathway of solar wind energy deposition into the atmosphere. The electric field in the high‐latitude region varies temporarily and spatially on a variety of scales. This modeling study investigates the impact of mesoscale electric field variability, where mesoscale is defined as a spatial scale between 100 and 500 km and a temporal scale between 2 and 15 min. We utilize numerical modeling and ground‐based radar observations to quantify the impact of mesoscale electric fields on the heating and dynamics of the high‐latitude upper atmosphere during a geomagnetic storm. Our results indicate that mesoscale electric fields induce significant enhancement in the Joule heating, temperature, density, and wind of the upper atmosphere. Key Points: Mesoscale high‐latitude electric fields significantly impact the thermospheric energy budget via enhanced Joule heating A 1 mW/m 2 enhancement in the total power flux can induce 50 K neutral temperature increase above 200 km altitude The excess energy deposits within a few minutes to increase the neutral density above 250 km altitude and accelerate the neutral wind