A new approach to air mass characterization over the Indian region using INSAT-3DR sounder data

This paper presents a first-time satellite-based air mass analysis over the Indian region using Indian National SATellite System (INSAT)-3DR sounder data. The Indian region is characterized by circulations and air mass fronts which have an influential role in deciding the synoptic weather. Usually, air mass analysis is carried out using radiosonde and atmospheric model-based reanalysis data. Both these datasets have intrinsic limitations due to sparse observations and other error sources. The present study is carried out using meteorologically significant satellite-derived 850 hPa level mixing ratio, optical depth, and equivalent potential temperature. The study elicits relative movements and mixing of different air masses during different seasons over the Indian region. The air mass features are well represented by mixing ratio and optical depth compared to potential temperature. The study brings forth prominent interacting air masses and their relative abundance during different seasons. The statistical analysis of air masses during different seasons at 850 hPa estimates the average values of physical attributes concerning different air masses. From the case analysis of air masses, at 850 hPa, a dry pool of mixing ratio is observed during the pre-monsoon (April–May) months. The analysis suggests that the reason for the formation of dry pool over Bay of Bengal and Arabian Sea is frequent anticyclonic formation during the period. The present study limelights the potential of satellite-derived mixing ratio profiles to understand the weather features associated with air mass interactions over the Indian region.