Simulation and data assimilation of South East Pacific (SEP) ocean mesoscale structure (Funded by NSF)The ability of high resolution eddy-resolving ocean models to accurately resolve the South East Pacific eddy structure will be critically tested using the VOCALS-REx (VAMOS Ocean-Cloud-Atmosphere-Land Study Regional Experiment) oceanographic mesoscale survey and satellite data. We are using ROMS (Regional Ocean Modeling System) to simulate the horizontal and vertical eddy structure. I plan to do a synthetic analyses for the Regional Experiment using ocean data assimilation to understand the eddy heat/freshwater/tracer/nutrient transports from the coastal upwelling region to the remote SEP, and interactions between the eddies, the mixed layer and the deeper ocean. I am currently testing data assimilation twin experiments in Incremental Strong-constraint 4DVAR (IS4DVAR) framework of a high resolution (7 km horizontal resolution) regional ocean model of the South East Pacific region under the guidance of Prof. Art Miller and Prof. Bruce Cornuelle. I have run sample experiments to test the corrections in the ocean state estimation due to data assimilation in twin experiments. I plan to use ship cruise data from the VOCALS-REx funded cruise in Oct-08 to assimilate real time data from satellites and ship cruise surveys to better estimate the ocean state for the period during the ship cruise.Inverse Methods for Data assimilation in nonlinear problems (Funded by ONR)I am also working to learn and extend the application of optimal nonlinear filtering theory for ocean state estimation in collaboration with Prof. Art Miller, Prof. Bruce Cornuelle and Prof. Ibrahim Hoteit. We are testing different flavors of Ensemble Kalman Filters and also learning to test particle filters to use in simple nonlinear problems such as Lorenz-96 model and then extend the study to simple ocean models such as the barotropic vorticity model. We plan to work on the development, implementation and testing of several Particle Kalman Filters in simple test cases to analyze their behavior and understand their merits and demerits in data assimilation for real ocean and atmospheric models.Coupled Ocean-Atmospheric processes in MJO-ENSO Dynamics (Funded by ONR)I am also analyzing coupled oceanic-atmospheric processes using a regional coupled model (SCOAR) in the Indian Ocean region to understand the controlling parameters on the Intraseasonal Oscillations of the Asian Summer Monsoon (ASM). This work is in collaboration with Prof. Art Miller, Prof. Raghu Murtugudde, Dr. Markus Jochum and Dr. Hyodae Seo. We are analyzing the influences of the air-sea fluxes and its variability on the intraseasonal variability of the ASM. Also, research interests diversify into the variability in the intraseasonal timescale in the internal ocean like the mixed layer and its predictability on the variability of the ASM at the intraseasonal timescale.I maintain my research pages with bibliography at these pages. Also, my calendar can be found at this page. |