...
首页> 外文期刊>Journal of geophysical research >Longitudinal variation in zonal winds at subauroral regions: Possible mechanisms
【24h】

Longitudinal variation in zonal winds at subauroral regions: Possible mechanisms

机译:Longitudinal variation in zonal winds at subauroral regions: Possible mechanisms

获取原文
获取原文并翻译 | 示例
           

摘要

abstract_textpLongitudinal differences in thermospheric zonal winds (Uy) are investigated in the subauroral region for different seasons and under solar maximum and medium conditions by using Challenging Minisatellite Payload observations. Prominent wave-1 longitudinal and diurnal variations of Uy are observed, along with an antiphase relationship between the Northern and Southern Hemispheres. These structures persist over the whole year and are independent of solar activity. Uy values are greater at nighttime than at daytime, and values in the south are greater than those in the north in local summer and winter. Model simulations confirm observed results in large-scale structures, and the nonzero dipole tilt is found to be vital for the longitudinal variation of the zonal wind. The neutral air pressure gradient caused by the day-night difference in solar heating is a major contributor to the observed Uy. The pressure effects are larger at nighttime than at daytime and larger in the Southern Hemisphere than in the Northern Hemisphere. Ion drag reduces the compatibility between the modeled and observed Uy as expected, with larger effects at nighttime than at daytime. Viscous force also reduces the compatibility between the modeled and observed Uy with greater effects at daytime, except at nighttime in the Southern Hemisphere. Similarly, the Coriolis force makes the difference between the modeled and observed Uy larger. The sum of these factors can explain, in general, the observed local time and hemispheric asymmetry features in longitudinal variation of the zonal wind./p/abstract_text

著录项

获取原文

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号