Solar-geomagnetic-climatic Relationships at Bombay

Abstract

Geomagnetic and meteorological data consisting of annual mean values for the period 1848-1967 from Colaba and Alibag Observatories, Bombay, situated on the sea-coast in the topics and under the strong influence of the Indian monsoon, are studied and their long-period variations examined against similar trends in the corresponding annual mean sunspot number. The increasing secular trend of the geomagnetic total intensity at Alibag appears to be inversely related to the surface atmospheric pressure trend and directly to the air temperature and the annual total rainfall trends at Colaba, contrary to the results given by some workers for various other stations around the world particularly in the higher latitudes. Climatic modulations, if any, due to the geomagnetic secular variation in the Indian region are greatly influenced by the local monsoon over long periods may be treated as two independent effects of solar activity.