Intercomparison review of IPWV retrieved from INSAT-3DR sounder, GNSS and CAMS reanalysis data

Abstract. The spatiotemporal variations of integrated precipitable water vapor (IPWV) are very important in understanding the regional variability vapor. Traditional situ measurements IPWV Indian region limited, and therefore performance satellite Copernicus Atmosphere Meteorological Service (CAMS) retrievals with Global Navigation Satellite System (GNSS) as reference were analyzed. In this study CAMS reanalysis data 1 year (2018) GNSS INSAT-3DR sounder retrieval for 1.5 years (January 2017 to June 2018) utilized, statistics computed. It is noticed that seasonal correlation coefficient (CC) values between mainly lie within range 0.50 0.98 all selected 19 stations except Thiruvananthapuram (0.1), Kanyakumari (0.31) Karaikal (0.15) during monsoon season Panjim (0.2) post-monsoon season. CC from 0.73 .99 Jaipur (0.16) Bhubaneswar (0.29) pre-monsoon season, (0.38) Nagpur (0.50) Dibrugarh (0.49) (0.58) winter root mean square error (RMSE) higher under wet conditions (pre-monsoon season) than dry (post-monsoon season), we found differences magnitude sign bias respect station This will help improve utilization more effectively along over land, coastal desert locations terms flow IPWV, which an essential variable forecasting applications.