SA037-10
New Characteristics of Quasi-6-Day Wave Modulations in Ionosphere during the 2019 Antarctic Sudden Stratospheric Warming by Using Global Ionosphere Specification

Wednesday, 16 December 2020: 09:06
Virtual
Jia-Ting Lin1, Charles C. H. Lin1, P. K. Rajesh2, Jia Yue3, Chi- Yen Lin4 and Tomoko Matsuo5, (1)National Cheng Kung University, Department of Earth Sciences, Tainan, Taiwan, (2)National Central University, Jhongli City, Taiwan, (3)NASA Goddard Space Flight Center, Community Coordinated Modeling Center, Greenbelt, MD, United States, (4)NCU National Central University of Taiwan, Center for Astronautical Physics and Engineering, Taoyuan, Taiwan, (5)University of Colorado Boulder, Boulder, CO, United States
Recorded Presentation
Abstract:
This study investigates new characteristics of ionospheric variations driven by quasi-6-day wave (Q6DW) burst following a rare and intense Antarctic sudden stratospheric warming (SSW) in September 2019. Local-time and vertical variations of amplitude and phase of Q6DW modulations of ionosphere during SSW are examined for the first time by using data-assimilated three-dimensional Global Ionosphere Specification (GIS) electron density. The GIS assimilates both FORMOSAT-7 radio occultation and ground-based GPS slant total electron content (TEC) to construct hourly electron density. The results show maximum amplitudes of Q6DW sit symmetrically ±20° off the magnetic equator ~12 LT followed a secondary peak at 17 LT. At 15 LT, the weakened amplitude and sudden phase shift of Q6DW suggests the ionosphere variations driven by multiple dynamo processes. Altitude-latitude structure shows Q6DW modulations extending beyond equatorial ionization anomaly, which indicates the dynamo effect should occur at higher latitudes off the equator. A plausible explanation is discussed based on interactions between Q6DW and other tidal winds leading to the phase differences and dynamo modulation.
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