The study of jet streams over India and to Its north in winter: Part I.

Abstract

Characteristic of the jet streams over India and to its nortl1 in winter were studied with the daily vertical cross-sections (1200 GMT) along 75°E from SoN to 60°N for the period 1 to 15 February 1967. It was observed that there are three separate jet cores present in this latitude belt on most of the days, located on an average at 43oN, 31ON and 23oN. Of these three, the most stable and persistent one is the second, which is located between Delhi and Srinagar, at 200-mb level with an average maximum speed of 140-145 kt. The one to its south is weaker and quite variable in location as well as altitude. The jet at 31oN, therefore, has been called the primary sub-tropical jet over India and its characteristics studied. Based on this study, a model cross-section has been prepared for this STJ. The descriptions of the STJ at 23oN and of PFJ (Polar Front Jet) at 43ON are included.