Subjects: Geosciences >> Space Physics submitted time 2017-03-10
Abstract：本文选择参数化的电离层热层理论模型TIEGCM作为背景模型，基于COSMIC 掩星观测的电子密度廓线数据，应用集合卡尔曼滤波方法建立了全球电离层电子密度同化模型，实现了全球电离层的电子密度同化。同化结果表明，该同化模型能将观测资料有效地同化到背景模式中，获得全球三维电离层电子密度。与背景模式相比，同化得到的电子密度相对于观测值的偏差显著下降。此外，分组同化与同时同化的结果对比显示，平均偏差改善基本一致，同时同化后的标准偏差在峰值高度以上略有减小。
Peer Review Status:
Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2017-01-22
Abstract： Parameterized ionosphere model TIEGCM is used as background model. Basing on the COSMIC observations, global ionospheric electron density assimilation model is established using ensemble Kalman filter. Result shows, this model can effectively assimilate observations into background model and acquire three dimensional ionospheric electron density. Compared to background, the error between analysis and observations decreases significantly. The root mean square error(RMSE) of NmF2 decreases about 60% for observations assimilated, and 20% for observations not assimilated. The RMSE of hmF2 doesn’t get improvement except for mean error. The results of simultaneous assimilation (SA) and batches assimilation (BA) are compared for this case. The time that the two methods spend in assimilation is about 6 to 7 minutes, which does not differ very much. SA needs nearly 8 GB storage while BA less than 2GB. The statistic of electron density error shows that they nearly acquire the same mean error, but the SA gets relative better improvement in RMSE above 250km.
Peer Review Status:Awaiting Review
Subjects: Geosciences >> Space Physics submitted time 2016-05-13
Abstract：利用全天时钠层荧光激光雷达和GPS电离层探测仪, 在2009年7月22日武汉日全食期间, 开展钠层与电离层的联合观测试验. 观测结果表明, 钠层密度半高全宽在日全食过程中稍有变窄, 而日全食过后增宽, 钠层峰值高度在日全食过程中稍有降低, 日全食过后高度略增, 钠层变化特性表现出快速的日出日落过程. 电离层电子总含量和天空背景光噪声也随日全食期间太阳辐照的变化而呈现出明显下降和上升的波动特征. 所不同的是, 钠层原子的这种半宽度起伏变化要比电离层的变化迟缓得多, 这可能是由于钠层受到日全食辐照扰动后, 会产生一系列复杂的光化学反应及动力输运过程, 再复合成钠原子被激光雷达探测到, 有一个滞后过程, 这也正好与理论模拟的结果相符.
Peer Review Status:Awaiting Review
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