Dr Sumant Nigam

My research is concerned with the analysis and modeling (i.e., dynamical diagnosis) of the recurrent modes of interannual climate variability, such as El Nino Southern Oscillation (ENSO), North Atlantic Oscillation (NAO), and the Pacific North American (PNA) variability pattern. Understanding the involved physical mechanisms is important as climate-change can manifest itself through modulations of the natural variability modes. I am also involved in the analysis and modeling of ocean-atmosphere interactions in the eastern tropical Pacific, where longwave cooling from the stratus cloud-tops leads to interesting radiative-dynamical coupling. I am heavily vested in the diagnosis of 3D diabatic heating from various reanalysis data sets, since 3D heating is a critical forcing in diagnostic climate models, and because of the need for observationally constrained validation targets for the GCM heating parameterizations.