Hypothesis about droughts, and zonal cell over north India during summer monsoon

Abstract

The zonal cell over north Indian during normal summer monsoon and its shift eastwards during droughts proposed by Pisharoty on the analogy of the zonal cell. in. the equatorial Pacific-Walker's cell discussed by Bjerknes has been critically examined. It is shown that, considering facts of the nature of the normal monsoon trough circulation and the associated rainfall distribution, temperatures at the surface, normal pressure distribution and the areas over which positive pressure anomalies occur, one cannot accept Pisharoty's hypothesis. It is also shown that there is no possibility of a zonal cell over the equatorial Indian Ocean envisaged by Bjerknes. In the to be the end, remarks about the lower monsoon trough and the upper easterly circulation have been made.