Dr Ratna is a senior scientist in the Office of Climate Research and Services, India Meteorological Department (IMD), Pune. He has an M.Sc. in Oceanography, an M.Tech. in Atmospheric Sciences, and a Ph.D. in Meteorology. His research interest is in the role of the ocean on climate variability ranging from interannual to multidecadal time scales and diagnosing the physical mechanisms. Some of the examples of his research include ocean-atmosphere interactions through the Atlantic Multidecadal Oscillation, the El Ninõ-Southern Oscillation, the Indian Ocean Dipole, and their influence on the Asian summer monsoon. More recently, in IMD, he has contributed to operational climate services, which include seasonal climate forecasts, ENSO/IOD forecast bulletins, climate applications for various sectors, coordination of the National Framework for Climate Services (NFCS), etc. He had earlier worked at the University of East Anglia, United Kingdom; the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Japan; and the Euro-Mediterranean Center on Climate Change (CMCC), Italy. Currently, he is also a member of the CLIVAR/GEWEX Monsoons Panel.