edu.ucar.opensky::articles:22588 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-25T15:34:44.920925 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7kw5k43 Empirical orthogonal function analysis and modeling of the topside ionospheric and plasmaspheric TECs 2019-05-01T00:00:00Z publication https://n2t.org/ark:/85065/d7kw5k43 https://doi.org/10.1029/2019JA026691 Zhong, J. author Lei, J. author Yue, X. author Wang, Wenbin author Burns, Alan author Luan, X. author Dou, X. author UCAR/NCAR - Library publisher The topside total electron contents (TECs) observed by the MetOp-A (above 832 km) and TerraSAR-X (above 520 km) satellites for multiple local times during 2008-2018 have been used to develop global topside ionospheric and plasmaspheric TEC models, based on empirical orthogonal function (EOF) analysis. Gridded TEC maps are first obtained from the original quiet time TECs, and then, they are decomposed into EOF basis modes and associated amplitude coefficients. The EOF analysis well captures the latitudinal, longitudinal, and seasonal variations of the topside ionosphere and plasmasphere, and the associated dependence on solar EUV forcing. The first five EOFs, which can account for more than 98.8% of the total variance, are applied in model construction. The comparison with two empirical models indicates that the EOF TEC models can reproduce the observations well, including TEC magnitudes and longitudinal variations. Moreover, the annual anomaly is obviously seen in the topside TECs. The global averaged TECs are greatest in December and smallest in June. With increasing solar EUV forcing, the global averaged TECs always increase, but the winter hemisphere TECs do not change much and even decrease, especially at night and in the Southern Hemisphere. The overall increasing rate with solar EUV forcing is larger under higher solar activity conditions. The direct plasma diffusion through ionosphere-plasmasphere coupling may not be able to explain some of the features seen in the topside TECs. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2019 American Geophysical Union. None eng geoscientificInformation