Rayleigh LiDAR investigation of stratospheric sudden warming over a low latitude station, Gadanki (13.5ºN; 79.2ºE) – a statistical study

Abstract

In this paper, the authors report the statistical characteristics of Stratospheric Sudden Warming (SSW) events observed over a low latitude station, Gadanki; 13.5°N, 79.2°E. The study uses 7 years (1998 to 2004) of quasi-continuous nighttime LiDAR temperature measurements, which corresponds to 312 observations. The statistical characteristics are presented in terms of major or minor, magnitude of warming, height of occurrence and stratopause descent with reference to the mean climatological profile. The warming events are classified into major or minor warming with respect to the observed warm temperature magnitude and reversal in the zonal wind direction in the polar region using National Centre for Environmental Prediction (NCEP) reanalysis data. In total, 14 SSW events observed and have been classified into 2 (14.3 %) major and 12 (85.7 %) minor warming events. The magnitudes of warm temperatures with respect to the mean winter temperature is in the range from 8.2 K to 18.1 K. Occurrence of SSWs are observed to accompany with the descent of stratopause layer from 0 km to 6.3 km with respect to the calculated mean winter stratopause height