Impact of ATOVS temperature and moisture profiles on NCMRWF analysis and prediction

Global high resolution (120 km) ATOVS temperature and moisture profile data from polar orbiting satellites NOAA 15 & 16 is been made available to u ser community recently by NESDIS (National Environm ental Satellite, Data and Information Service). NCMRWF al so has started using these products in its operatio nal global data assimilation system. Extensive impact assessment e xperiments have been conducted prior to its operati on l utilization. Impact is also studied during the onset phase of so uthwest monsoon over India. Results of these experi ments are presented in this article. Study show that the impa ct of ATOVS data is seen on the mean analysed and p redicted fields upto 120 hrs prediction specially over the oceanic region. It also reveals that the utilization of the se data is able to predict the rainfall over the Indian peninsular region and the adjoining ocean in more realistic manner upto 7 2 hr forecast, beyond which there is hardly any meaningful improve ment.