Observed change in association of temperature with solar activity in upper troposphere and lower stratosphere after 1977

Abstract

This paper presents the analysis of upper tropospheric and lower stratospheric (UTLS) region for the change in the solar dependence of temperature in the last half century, i.e. the second global warming episode. Analysis shows that the solar dependence of temperature at different levels, viz. 500, 300, 200, 100 and 50 mb has abruptly changed after 1977. The change is recorded around the world in UTLS region with its irrefutable prominence around the tropopause (near 100 mb pressure level or 16 km height over equator and 250 mb pressure level or 10 km height over the poles). The abrupt and continuous increase in number of El Nino events, after 1977 as compared to the number of La Nina events, is examined with other global phenomenon, such as global warming, ozone depletion, polar vortex and increase in greenhouse gases to be a probable mechanism triggering this change. Observations indicate that it is actually the change in solar dependence of temperature that leads to the global warming.