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Longitudinal variations of electron temperature and total ion density in the sunset equatorial topside ionosphere
Author(s) -
Ren Zhipeng,
Wan Weixing,
Liu Libo,
Zhao Biqiang,
Wei Yong,
Yue Xinan,
Heelis Roderick A.
Publication year - 2008
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2007gl032998
Subject(s) - solstice , daytime , sunset , equinox , ionosphere , wavenumber , electron density , noon , atmospheric sciences , amplitude , f region , geology , physics , electron , latitude , geodesy , geophysics , optics , quantum mechanics
Based on the DMSP F13 Satellite observations from 1995 to 2005, the longitudinal distributions of the electron temperature (T e ) and total ion density (N i ) in the sunset equatorial topside ionosphere are examined. The results suggest that the longitudinal variations of both T e and N i exhibit obvious seasonal dependence as follows: (1) wavenumber‐four longitudinal structure in equinox, (2) three peaks structure in June solstice, and (3) two peaks structure in December solstice. Moreover, the longitudinal variations of T e and N i show significant anti‐correlation, and we speculate that the longitudinal variation of T e may result from that of N i which can control T e through the electron cooling rate. The wavenumber‐four longitudinal structures of both T e and N i in equinox may relate to the eastward propagating zonal wavenumber‐3 diurnal tide (DE3), which has effect on the amplitude of the daytime zonal electric field. The longitudinal variation of T e and N i in the two solstices may be caused both by longitudinal variation of geomagnetic declination and DE3.