Tropical stratopause features - Rayleigh lidar observations over Gadanki (13.5°N, 79.2°E), India

Abstract

International audienceThe characteristics of straggle feature "Double stratopause" observed in temperature profiles using Rayleigh lidar at National Atmospheric Research Laboratary (NARL), Gadanki (13.5°N, 79.2°E), India is presented in this paper. Out of 216 nights of observations made during March 1998-April 2001, the double stratopause is observed for 122 days (~56.5 %). The two stratopause peaks are found to be separated by ~2-10 km. Applying third order polynomial fit to the mean temperature profiles provided the quantification on peak and trough stratopause heights and temperatures. The monthly percentages of occurrence of double stratopause show peaks in June and September with weak seasonal dependence. The splitting in stratopause is considered in terms of gravity wave breaking due to Kelvin Helmholtz instability. There appeared to be a sudden increase in gravity wave potential energy in stratopause region during the presence of its split and also observed a maximum speed in wind, derived from NCEP reanalysis data