Ionospheric and induced field leakage in geomagnetic field models, and derivation of candidate models for DGRF 1995 and DGRF 2000
Ionospheric and induced field leakage in geomagnetic field models, and derivation of candidate models for DGRF 1995 and DGRF 2000
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DOI：
10.1186/bf03351903
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发表时间：
2005-01-01
影响因子：
3
通讯作者：
Sabaka, TJ
中科院分区：
文献类型：
--
作者：
Olsen, N;Lowes, F;Sabaka, TJ
作为IAGA定义的第9代IGRF的一部分，我们提出了DGRF 1995的候选模型和DGRF 2000的两个候选模型。这些候选模型基于“综合模型，版本4 （CM4）”和“Orsted主要和长期变化模型（OSVM）”，其推导在本说明中有所描述；在其他地方发表的两个母模型（Olsen, 2002; Sabaka et al., 2004; Lowes and Olsen, 2004）。然而，OSVM的主场部分受到电离层场及其诱导对应物的“泄漏”污染，主要影响纬向系数g(1)(0), g(3)(0)，…我们描述了这种污染的原因，并提出了一种纠正它的方法。由于不仅OSVM，而且可能所有主要来自当地午夜前后数据的主要场模型都受到这种影响，因此所提出的方案也可以应用于近似校正这些模型。
As part of the 9th generation of the IGRF defined by IAGA, we proposed a candidate model for DGRF 1995 and two candidate models for DGRF 2000. These candidate models, the derivation of which is described in the present note, are based on the "Comprehensive Model, Version 4 (CM4)", and on the "Orsted Main and Secular Variation Model (OSVM)"; two parent models that have been published elsewhere (Olsen, 2002; Sabaka et al., 2004; Lowes and Olsen, 2004). However, the main field part of OSVM is contaminated by "leakage" of the ionospheric field and its induced counterpart, which affects mainly the zonal coefficients g(1)(0), g(3)(0),..., by 1-2 nT. We describe the reason for this contamination, and present a method to correct for it. Since not only OSVM but probably all main field models that are derived primarily from data around local midnight suffer from this effect, the presented scheme can also be applied to approximately correct these models.