Abstract
The paper defines the intertropical convergence zone. (ITCZ) in the Indian monsoon region during the northern summer, identifies it with the northern boundary of the advancing monsoon and suggests that its seasonal movement can serve as an indicator of onset, advance and withdrawal of the monsoon. Evidence suggesting the movement of the ITCZ which is associated with the equatorial trough of low pressure is indirectly furnished by an analysis of the isallobaric or height-tendency field which reveals a distinct gradient towards the north/south during period of advance/withdrawal of the monsoon. A comparative study of the dates of onset of monsoon during two successive years appears to suggest that some of the problems encountered in using rainfall as the sole criterion for determining the onset and advance of the monsoon may be over-come by using the ITCZ concept as proposed in the present paper. Attention is drawn to the effects of synoptic-scale disturbances on the normal dates of onset, advance and withdrawal of the monsoon.
Similar content being viewed by others
References
Ananthakrishnan, R., Acharya, U. R. andRamakrishnan, A. R. (1967),On the criterion for declaring the onset of the southwest monsoon over Kerala India Meteorological Department Forecasting Manual, Part IV, No. 18.
India Meteorological Department (1943),Climatological charts for airmen.
Petterssen, S. (1956),Weather Analysis and Forecasting (Second edition), Vol. 1, McGraw-Hil Book Co., Inc., New York, 428 pp.
Ramage, C. S. andRaman, C. R. V. (1972),Meteorological Atlas of the International Indian Ocean Expedition, Vols. 1 and 2, National Science Foundation, U.S.A. Charts numbers 9, 19, 39. ... 119.
Sawyer, J. S. (1947),The structure of the intertropical front over northwest India during the south-west monsoon. Quart. J. Roy. Meteor. Soc.,73, 346–369.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Saha, S., Saha, K. A hypothesis on onset, advance and withdrawal of the Indian summer monsoon. PAGEOPH 118, 1066–1075 (1980). https://doi.org/10.1007/BF01593050
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01593050