Premium
Unique latitudinal shape of ion upper transition height ( H T ) surface during deep solar minimum (2008–2009)
Author(s) -
Tulasi Ram S.,
Heelis R.,
Gowtam V. Sai,
Ajith K. K.,
Su S.Y.
Publication year - 2015
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
eISSN - 2169-9402
pISSN - 2169-9380
DOI - 10.1002/2014ja020647
Subject(s) - latitude , ionosphere , atmospheric sciences , low latitude , flux (metallurgy) , ion , solar minimum , physics , solar cycle , chemistry , plasma , geophysics , solar wind , astronomy , quantum mechanics , organic chemistry
The ionospheric upper transition height ( H T ) is found to increase dramatically by ~100 km 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 ~550 to 650 km 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 ~550 km.