1. 学术报告：Effects of magnetospheric lobe-cell convection on upper thermospheric winds in the polar cap 时间：2016年3月14日上午10点 地点：教学行政楼1514室 报告人：Bizheng Zhang博士 单位：美国国家大气研究中心 摘要：This study investigates possible connections between the observed dayside equatorward wind in the upper thermosphere by the HIWIND balloon experiment and magnetospheric lobe-cell convection in the polar cap using numerical simulations from the first-principles, physics-based coupled magnetosphere-ionosphere-thermosphere (CMIT) model. Observations have shown that these lobe cells occur frequently in the summer hemisphere during IMF By dominant periods. Theoretical studies have shown that the lobe-cell phenomenon is a magnetospheric response to merging site asymmetries imposted by dipole tilt, IMF Bx and By. When the high-latitude forcing is from a global magnetosphere model driven by realistic upstream conditions, the thermosphere-ionosphere electrodynamic general circulation model (TIEGCM) is capable of reproducing the observed equatorward neutral wind in the upper thermosphere. When the high-latitude forcing is empirical models, the TIEGCM predictions of meridional neutral winds deviate significantly from observations. Data-model comparisons suggest that magnetospheric lobe-cell convection may have significant influence on thermospheric winds in the polar cap during geomagnetic quiet time through ion-neutral coupling.

Qinxiu Li Posted at 2016-03-07 09:54 CST Last modified at 2016-03-07 09:54 CST Link to this poster Top