Atmospheric circulation during active and break phases of Indian summer monsoon: A study using MST radar at Gadanki (13.5°N, 79.2°E)

Abstract

The unique facility of measuring vertical winds using Indian mesosphere, stratosphere, and troposphere (MST) radar along with zonal and meridional winds enables the study of atmospheric circulation over Gadanki (13.5°N, 79.2°E) during the Indian summer monsoon season. The mean meridional circulations during winter and monsoon seasons represent part of two different Hadley circulations. The winter Hadley cell is observed to be stable whereas the monsoon Hadley cell seems to vary and depends on the monsoon activity. During active phase of the monsoon, the Hadley cell extends to the north, and during weak phase, it extends to the south of the study region. The observed features are compared with the winds obtained from National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data. The present study emphasizes that the atmospheric circulation during monsoon season is to be studied separately for active and break phases. Copyright 2008 by the American Geophysical Union.