Wavenumber‐4 patterns of the total electron content over the low latitude ionosphere
Wavenumber‐4 patterns of the total electron content over the low latitude ionosphere
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DOI：
10.1029/2008gl033755
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发表时间：
2008-06
影响因子：
5.2
通讯作者：
W. Wan;L. Liu;X. Pi;M.-L. Zhang;B. Ning;J. Xiong;F. Ding
中科院分区：
文献类型：
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作者：
W. Wan;L. Liu;X. Pi;M.-L. Zhang;B. Ning;J. Xiong;F. Ding
利用喷气推进实验室制作的全球电离层地图(GIM)研究了低纬电离层的纵向结构。作为低纬电离参数的替代，首先从低纬GIM中提取纬向积分总电子含量(ITEC)，然后进行傅立叶滤波得到波数为4的分量。然后，我们详细地研究了波动模式的日变化、季节变化和太阳周期变化。结果表明，北半球夏季和初秋波数-4型较强且发达，而北半球冬季波数-4型较弱。这种季节变化与非迁移型潮汐模式DE3的纬向风的季节变化相一致。我们还发现，波数为4的波型向东移动，其移动速度白天小于夜间。这是由于E区DE3向东传播和F区E×B离子纬向漂移共同作用的结果。我们的结果支持低纬电离层的纵向波数-4结构应起源于非迁移型潮汐模式DE3的观点。
The global ionospheric maps (GIMs) produced by JPL are used to investigate the longitudinal structure of the low latitude ionosphere. As a proxy of the ionization parameter at low latitudes, the latitudinally integrated total electron content (ITEC) is first extracted from low latitude GIMs and then Fourier filtered to obtain the wavenumber‐4 components. We then study in detail the diurnal, seasonal and solar cycle variations of the wave patterns. It is found that the wavenumber‐4 patterns are intense and well developed in boreal summer and early boreal autumn, but quite weak in boreal winter. This seasonal variation is consistent with that of the zonal wind of the non‐migrating tide mode DE3. We also found that the wavenumber‐4 patterns shift eastward with a shifting speed that is smaller in daytime than at night. This is attributed to the contribution of both the eastward propagation of DE3 in E‐region and the zonal E ×B ion drifts in F‐region. Our results support the suggestion that the longitudinal wavenumber‐4 structure of the low latitude ionosphere should be originated from the non‐migrating tide mode DE3.