Tropical temperature altitude amplification in the hiatus period (1998-2012)

Abstract

There was a stagnation in temperature rise in the period 1998-2012, despite increase in greenhouse gases radiation forcing (hiatus period). According to Global Circulation Models simulations, expected response on the rise of greenhouse gases forcing is tropical temperature altitude amplification temperature increases faster in higher troposphere than in lower troposphere. In this paper, two satellite data sets University of Alabama in Huntsville, Microvawe Sounding Units (UAH MSU) and Remote Sensing Systems (RSS), were used to test altitude temperature amplification in tropics in the hiatus period. We compared satellite data sets both for the temperature of the lower troposphere and the temperature of the middle troposphere, in general and particularly for land and ocean (for UAHMSU). The results from both satellite measurements showed the presence of hiatus, i.e. slow-own of the temperature rise in the period 1998-2012 compared to period 1979-2012 (UAHMSU) and temperature fall for RSS. Smaller increase, i.e. temperature fall over ocean showed that hiatus is an ocean phenomenon above all. Data from UAH MSU showed that temperature altitude amplification in tropics was not present either for period 1979-2012, or 1998-2012. RSS data set also does not show temperature altitude amplification for these periods. RSS data for successive 15-year periods from 1979-1993 till 1998-2012 does not show tropical temperature altitude amplification and in one case negative trend is registered in lower troposphere and in two cases in middle troposphere. In general, our results do not show presence of temperature altitude amplification in tropics in the hiatus period.