Climatology of the atmosphere up to 30 km over Thumba

Abstract

Wind and temperature data from surface to 30 km over Thumba for a period of 23 years from 1970 to 1992 are analyzed. The long term mean pattern of the wind components and temperature as well as their amplitude and phase as well as their cycle-to-cycle variations are brought out. Also, the variations of the annual mean temperatures are worked out and vertical profile of these variations presented. The mean wind and temperature structure and characteristics of the quasi-biennial, annual and semi-annual oscillations in winds and temperature up to 30 km agree with the earlier results obtained from shorter data periods. Apart from this the present analysis reveals a rising trend in the annual mean temperature at all levels in the troposphere over Thumba. It is also seen that the monthly mean temperatures around 18 km are warmer by about 5K from the annual mean during the peak of the tropical easterly jet at around 15 km.