Climatology of medium-scale traveling ionospheric disturbances observed by a GPS network in central China
会议名称：《中国科学院地质与地球物理研究所第11届（2011年度）学术年会》
会议日期：2012年
学科分类：070802[理学-空间物理学] 07[理学] 0708[理学-地球物理学]
基 金：supported by the National Natural Science Foundation of China(grants 40974089,41131066,40931056,and 40974094) the National Important Basic Research Project of China(2011CB811405) the Scientific Research Project of IHR,CMA(grant 1007)
摘 要：[1]The 15-month climatology of medium-scale traveling ionospheric disturbances (MSTIDs) during a solar minimum period has been constructed from observations of a dense GPS receiver array in Central *** total,793 MSTID events are identified, with peaks in occurrence at 1500 LT and 0100 *** occurrence of MSTIDs decreases following an increase in geomagnetic activity,with 46%of the MSTIDS occurring in the *** MSTIDs are characterized by a major occurrence maximum around the winter solstice and by an equatorward propagation *** period,phase velocity,azimuth,and amplitude of daytime MSTIDs are 20-60 min,100-400 m/s, 130°-270°,and 0.8-1.5%,*** remaining 54%of the MSTIDs occurred at night,and were characterized by a peak in occurrence at the summer solstice and by a southwestward propagation *** period,phase velocity,azimuth,and amplitude of nighttime MSTIDs are 20-70 min,50-230 m/s,170°-300°,and 2-7%,respectively. The propagation directions and the seasonal behaviors support the view that daytime MSTIDs are an ionospheric manifestation of atmospheric gravity waves from the lower atmosphere,while a possible excitation mechanism of nighttime MSTIDs is the electrodynamics process caused by plasma instability in the F layer.