Continentality trends over India and the neighbourhood

Abstract

The paper is an extension of another article published by the author earlier. The purpose of the work presented herein is to emphasize the role of thermal continentalities in the study of general climatology. The parameter chosen for the analytical study is K* defined (previously) as the ratio of actual to expected summer concentrations of thermal efficiency, a concept first recognized by Thornthwaite.

                 Making use of the values of K* for about 250 stations in and around India, computed as explained in the previous paper, an iso-continental map was prepared and presented. The outstanding feature of the map is the division of the country into two major (the super and the sub-continental) zones of different continentality characteristics, the demarcating line being the isopleth of K*= 100 per cent. Comparison of this map with other climatic maps shows striking similarities to the moisture rather than the thermal indices, lending support to the view that the continentality traits of a region are determined essentially by its moisture regime.

            The altitudinal variation of K* in the two zones referred above show certain highly interesting features. Levels of normal continentality, continentality reversal and continentality invariance are identified and it is felt that further extension of the work on a quantitative basis may reveal other features of great significance to the physical climatology of India and the neighbourhood.