講演情報
[PEM12-P20]How do Space Hurricanes Disturb the Polar Thermosphere: A Statistical Survey
*Zhi-Feng Xiu1、Yu-Zhang Ma1、Qing-He Zhang2、Zan-Yang Xing1、Larry Lyons3、Kjellmar Oksavik4,5、Yong-Liang Zhang6、Marc Hairston7、Yong Wang1、Duan Zhang2、Sheng Lu1 (1.Shandong University、2.National Space Science Center、3.University of California, Los Angeles、4.University of Bergen、5.University Centre in Svalbard、6.The Johns Hopkins University Applied Physics Laboratory、7.University of Texas at Dallas)
The space hurricane is a polar cap auroral structure with strong flow shears and intense particle precipitation that can disturb the thermosphere under quiet geomagnetic conditions. Here the statistical characteristics of this interaction are surveyed using data from the DMSP and GOCE satellites. The results confirm that space hurricanes modify the ion and neutral circulation in the polar cap through enhanced electric fields. Local precipitation, particularly >500 eV electrons, which raises the Pedersen conductance, leads to enhanced Joule heating and the generation of gravity waves. Electric fields play a leading role on the dawn side of the space hurricane. Gravity waves are also mainly located on the dawnside of the space hurricane, with a maximum vertical wind of 37 m/s and a 17% neutral density disturbance. These findings augment our awareness of magnetosphere-polar ionosphere-thermosphere coupling under quiet northward IMF conditions.