On the Structure of Monsoon Lows over the Inland Area of Northern India

Abstract

The mean vertical structure of monsoon lows over the inland area of northern Indiais investigated by the method of spectral analysis. It is compared with the result of Murakami (1976) in which the data of the station located on the coast of the Bay of Bengal are used. The structures of both stations show that the cyclonic circulation of monsoon lows prevails in the lower troposphere and their axis tilts slightly westward with height. They also bear warm-cored structure in common in the upper levels.
The most remarkable contrast appears in the field of specific humidity. When monsoon lows are in the vicinity of the Bay of Bengal, moistening occurs in coincidence with southerly winds, i.e. in the east of the trough. On the contrary, moist and cold anomalies appear in the west of the trough with northerly winds over the inland area. These contrasts suggest an intense geographic effect of Indian subcontinent on the life cycle of monsoon lows.