Comparative climatological study of large-scale traveling ionospheric disturbances over North America and China in 2011-2012
Comparative climatological study of large-scale traveling ionospheric disturbances over North America and China in 2011-2012
复制标题
2011-2012年北美和中国大范围移动电离层扰动对比气候学研究
DOI：
10.1002/2013ja019523
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发表时间：
2014-01-01
影响因子：
2.8
通讯作者：
Xiong, Bo
中科院分区：
文献类型：
--
作者：
Ding, Feng;Wan, Weixing;Xiong, Bo
基于2011-2012年北美和中国大尺度移动电离层扰动（LSTIDs）的气候对比研究。我们在中国共发现390个lstid事件，在北美发现363个lstid事件。它们可以分为三种类型，即南传播、北传播和向西传播的lstid。北美的南向lstid与地磁扰动的日变化和季节变化相似，而中国的南向lstid则没有这种变化。在地磁活动极大期后1 ~ 2 h，中国大陆上南向LSTIDs的发生增加；这种增加持续了几个小时，直到地磁极小期，发生在当地的晚上。北美地区南向LSTIDs呈半年变化，在3月和10月出现两个高峰，而中国地区南向LSTIDs在1月出现一个高峰。北向LSTIDs的发生频率远低于南向LSTIDs，且主要发生在中国。它们大多发生在地磁活动最剧烈的时候，表明它们可能与地磁活动的程度有关。在当地日出时，在这两个地区都可以看到向西的lstid，并且可能被移动的太阳终端线激发。这些后一种lstid与地磁扰动之间没有关系。西进事件的传播方向由冬至时的西北向转变为夏至时的西南向。这与太阳终端机的季节方向一致。
This paper describes a comparative study of the climatology of large-scale traveling ionospheric disturbances (LSTIDs) over North America and China based on observations obtained in 2011-2012 using two GPS networks characterized by dense regional coverage. We identified a total of 390 LSTIDs in China and 363 events in North America. These can be categorized into three types, namely south, north, and westward propagating LSTIDs. The southward LSTIDs over North America show similar diurnal and seasonal variations to those of geomagnetic disturbances, but the southward LSTIDs over China do not show such variations. The occurrence of southward LSTIDs over China increases at similar to 1-2 h after the time of geomagnetic activity maximum; this increase lasts several hours until the geomagnetic minimum, which happens during the local evening. The southward LSTIDs over North America show a semiannual variation with two peaks in March and October, while the southward LSTIDs over China show a major peak in January. Northward LSTIDs occur much less frequently than their southward counterparts, and they are mainly observed in China. They mostly occur during geomagnetic activity maximum, indicating a possible relation with the degree of geomagnetic activity. Westward LSTIDs are seen in both regions during local sunrise and may be excited by the moving solar terminator. No relationship was found between these latter LSTIDs and the geomagnetic disturbances. The propagation direction of westward events changed from northwestward during winter solstice to southwestward at summer solstice. This is consistent with the seasonal orientation of the solar terminator.