The correlation of longitudinal/seasonal variations of evening equatorial pre-reversal drift and of plasma bubbles
The correlation of longitudinal/seasonal variations of evening equatorial pre-reversal drift and of plasma bubbles
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DOI：
10.5194/angeo-25-2571-2007
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发表时间：
2007-01
影响因子：
1.9
通讯作者：
Guozhu Li;B. Ning;Libo Liu;Z. Ren;J. Lei;S. Su
中科院分区：
文献类型：
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作者：
Guozhu Li;B. Ning;Libo Liu;Z. Ren;J. Lei;S. Su
摘要。傍晚反转前垂直漂移速度增强（PRE）是F区不规则性产生的重要种子机制。利用ROCSAT-1和DMSP卫星的离子密度和漂移测量数据，研究了电离层上部磁赤道晚反转前垂直漂移速度的纵向/季节（l/s）变化与等离子体气泡（PB）发生概率的相关性。对2000-2002年（太阳活动极大期）3年的分析提供了与地面观测一致的证据，表明赤道PB的发生依赖于PRE，并与PRE近似线性增加，PRE的l/s变化在全球PB发生的l/s分布中起重要作用。冬至晚PRE和赤道PB出现的纵向变化相似：在6月至期间，非洲和太平洋经度出现两个峰值，印度和美洲地区出现两个最小值；在12月至日期间，情况大致相反。分点的纵向影响相对较小。认为赤道PB产状的大尺度l/s变化与PRE的l/s变化密切相关。
Abstract. The evening pre-reversal vertical drift velocity enhancement (PRE) constitutes an important seeding mechanism for the generation of F region irregularities. Ion density and drift measurements from ROCSAT-1 and DMSP satellites are used to examine the correlation of longitudinal/seasonal (l/s) variations in the evening pre-reversal vertical drift velocity at the magnetic equator in the topside ionosphere and the plasma bubble (PB) occurrence probability. The analysis performed for three years 2000–2002 (solar maximum), provides consistent evidence as the ground observations that the equatorial PB occurrence is dependent on and increases approximately linearly with PRE, and the l/s variations of PRE play an important role in the global l/s distribution of PB occurrence. The solstitial evening PRE and equatorial PB occurrence show similar longitudinal variations: During June solstice, two peaks appear in the African and Pacific longitude sectors, and two minimums are observed in the Indian and American regions; During December solstice, the situation is approximately opposite. The equinoctial longitudinal effects are comparably small. It is concluded that the large-scale l/s variations of equatorial PB occurrence can be closely related to the l/s variations of PRE.