Chapters authored
Dual Nature of Land Ocean Thermal Contrast during Pre-Monsoon and Onset Phase of Indian Summer Monsoon
Under faster Indian Ocean (IO) warming, several thermodynamical properties of the atmosphere over the Indian sub-continent change abruptly. The present study has evaluated the temperature field using ERA5 and IMDAA reanalysis. From the climatological evolution, it has been observed that before monsoon onset over Kerala (MOK) not only does meridional tropospheric temperature gradient reverses from negative to positive but the surface LOTC also decline very sharply. Interannual variation of LOTC shows that there is no significant trend, however, warming since 1980 may lead to an increase in variability. The reason behind having no trend in LOTC may be attributed to land ocean warming ratio (WR). Composite analysis depicts that except for early MOK, surface LOTC decreases sharply before MOK while deep tropospheric LOTC or meridional tropospheric temperature increases. The climatological average of pre-monsoonal average is about −5.52 K which has been found slightly higher (−4.9 K) during the early MOK years and found slightly lower (−5.7 K) during the delayed MOK years. Hence deep tropospheric LOTC is mostly used to identify the onset of MOK while surface LOTC can be utilized to predict MOK. However, to make a more precise MOK prediction, the interaction between three-dimensional temperature field with large-scale flow needs to explore.
Part of the book: Global Warming [Working title]