Global warming is causing more extreme precipitation events and variability in rainfall patterns, which are affecting the timing of peak rainfall occurrence and impacting the hydrological cycle in evolving climates. This study examines spatial rainfall trends across India during the Indian Summer Monsoon (ISM) period from 2001 to 2020, utilizing GSMaP_ISRO data. Analysis reveals a significant rise of 2 mm/day in rainfall over west central India from 2011 to 2020. Additionally, an investigation into the timing of peak rainfall demonstrates an early (late) peak over the Indo-Gangetic Plain (central India) in recent years, likely influenced by changes in aerosol loading. The present results suggest a significant shift in rainfall peak time with potential implications for agriculture,hydrology and disaster management.

Earth Observation Satellite (EOS)-04 launched on 14th February 2022, carries a C-band Synthetic Aperture Radar (SAR) for Agriculture, Forestry, Hydrology and Flood mapping applications. In this paper, we have used C-band SAR images and near-simultaneous observations from the Global Precipitation Measurements (GPM) to study the signatures of multiple convective rain cells. The bright patches are found on C-band SAR imagery, which depicts the information of hydrometeors such as graupels or hails in the melting layer. For the first time, unambiguously estimated the diameter of the convective core rain cells from the C-band SAR backscattered signal and compared near-simultaneous observations from GPM-GMI and Ku-band radar to confirm our findings. In future, we will decipher between convective and stratiform rain signatures on C-band SAR imagery and the possibility between C-band backscattered signals with lighting events. Thus, the present study demonstrates the potential of C-band SAR for the signatures of convective rain cells.

The vertical structure and dynamics of deep convective clouds plays an important role during the Indian summer monsoon period. The characteristics of deep convective cells (DCC) and their microphysics remain unclear, especially during the onset phase of the monsoon. Further, the intensity of convection is an important element, which plays a key role in the progression of the monsoon. Thus the present study focuses on characterizing DCC over a coastal location Thumba (8.50 N, 770E) during the onset of the Indian summer monsoon periods of 2017, 2018 and 2019 using C-band polarimetric Doppler Weather Radar (DWR) measurements in terms of their intensity, vertical extent, top heights and their microphysical properties. A method is devised to identify the DCC from the DWR observed reflectivity cross-sections. The results showed that the occurrence of reflectivities in the range of 30-40 dBZ dominates below 6 km and the reflectivities in the range of 10-20 dBZ dominates above 6 km. The diurnal evolution of DCC also been investigated and it is found that these systems peak at three local time intervals viz., 5-7, 11-14 and 16-19 hrs during the study period. The present results provide a quantitative assessment of DCC including their diurnal evolution during the onset of Indian summer monsoon season over Thumba using DWR observations for the first time.