Unique latitudinal shape of ion upper transition height (H-T) surface during deep solar minimum (2008-2009)

作者：Ram S Tulasi^*; Heelis R; Gowtam V Sai; Ajith K K; Su S Y

来源：JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS, 2015, 120(2): 1419-1427.

DOI：10.1002/2014JA020647

• topside ionosphere
• ion transition height
• ion composition
• charge exchange

The ionospheric upper transition height (H-T) is found to increase dramatically by similar to 100km from 2008-2009 to 2010 only for a marginal increase in solar activity (F-10.7) by 11.76 solar flux units. The latitudinal variation of H-T surface during 2008-2009 period exhibits a local minimum at equatorial latitudes and increase at low latitudes. Further, the H-T at equatorial latitudes exhibits slower rate of increase than at low latitudes. These interesting features are new and different from those reported in literature. A quick loss of O+ and increase in H+ ions are observed around similar to 550 to 650km indicating that the charge exchange reaction is responsible for the slower rate of increase and lowered H-T at equatorial latitudes. These new aspects of H-T are more conspicuously observed during this deep solar minimum period where the resonant charge exchange reaction is taking place at altitudes as low as similar to 550km.

• 出版日期2015-2
• 单位中央民族大学