Figure 9. Annual cycle of tropospheric temperature (TT) over the Indian region. (a) time-latitude plot of climatological upper troposphere (600–200 mb), temperature (oK) averaged over 70oE to 90oE. (b) Seasonal evolution of north-south gradient in 600–200 hPa temperature calculated as difference in TT over the two boxes marked in Figure8. The vertical black line is indicating June 1.