Statistical characteristics of the total ion density in the topside ionosphere during the period 1996-2004 using empirical orthogonal function (EOF) analysis

	Statistical characteristics of the total ion density in the topside ionosphere during the period 1996-2004 using empirical orthogonal function (EOF) analysis
	Zhao, B ; Wan, W ; Liu, L ; Yue, X ; Venkatraman, S
刊名	ANNALES GEOPHYSICAE
	2005
卷号	23 期号:12 页码:3615-3631
关键词	Ionosphere Equatorial Ionosphere Modeling And Forecasting Solar Radiation And Cosmic Ray Effects
ISSN号	0992-7689
文献子类	Article
英文摘要	We have applied the empirical orthogonal function (EOF) analysis to examine the climatology of the total ion density Ni at 840 cm during the period 1996-2004, obtained from the Defense Meteorological Satellite Program (DMSP) spacecraft. The data set for each of the local time (09:30 LT and 21:30 LT) is decomposed into a time mean plus the sum of EOF bases E-i of space, multiplied by time-varying EOF coefficients A(i). Physical explanations are made on the first three EOFs, which together can capture more than 95% of the total variance of the original data set. Results show that the dominant mode that controls the Ni variability is the solar EUV flux, which is consistent with the results of Rich et al. (2003). The second EOF, associated with the solar declination, presents an annual (summer to winter) asymmetry that is caused by the transequatorial winds. The semiannual variation that appears in the third EOF for the evening sector is interpreted as both the effects of the equatorial electric fields and the wind patterns. Both the annual and semiannual variations are modulated by the solar flux, which has a close relationship with the O+ composition. The quick convergence of the EOF expansion makes it very convenient to construct an empirical model for the original data set. The modeled results show that the accuracy of the prediction depends mainly on the first principal component which has a close relationship with the solar EUV flux.
WOS关键词	SOLAR-ACTIVITY VARIATIONS ; GREAT MAGNETIC STORM ; EQUATORIAL IONOSPHERE ; SEMIANNUAL VARIATIONS ; SEASONAL-VARIATIONS ; ELECTRON-DENSITY ; NEUTRAL WINDS ; PLASMA DRIFTS ; TEMPERATURE ; F2-LAYER
WOS研究方向	Astronomy & Astrophysics ; Geology ; Meteorology & Atmospheric Sciences
语种	英语
出版者	EUROPEAN GEOSCIENCES UNION
WOS记录号	WOS:000235008400006
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/65538]
专题	中国科学院地质与地球物理研究所
通讯作者	Wan, W
作者单位	1.Chinese Acad Sci, Inst Geol & Geophys, Beijing 100029, Peoples R China 2.CAS, Wuhan Inst Phys & Math, Wuhan 430071, Peoples R China 3.Chinese Acad Sci, Grad Sch, Beijing, Peoples R China 4.Univ Texas, William B Hanson Ctr Space Sci, Richardson, TX USA
推荐引用方式 GB/T 7714	Zhao, B,Wan, W,Liu, L,et al. Statistical characteristics of the total ion density in the topside ionosphere during the period 1996-2004 using empirical orthogonal function (EOF) analysis[J]. ANNALES GEOPHYSICAE,2005,23(12):3615-3631.
APA	Zhao, B,Wan, W,Liu, L,Yue, X,&Venkatraman, S.(2005).Statistical characteristics of the total ion density in the topside ionosphere during the period 1996-2004 using empirical orthogonal function (EOF) analysis.ANNALES GEOPHYSICAE,23(12),3615-3631.
MLA	Zhao, B,et al."Statistical characteristics of the total ion density in the topside ionosphere during the period 1996-2004 using empirical orthogonal function (EOF) analysis".ANNALES GEOPHYSICAE 23.12(2005):3615-3631.