Implementation of altimeter data assimilation on a regional wave forecasting system and its impact on wave and swell surge forecast in the Indian Ocean

In the present work, we have operationally implemented a data assimilation (DA) scheme in wave forecasting system at Indian operational agency, National Centre for Ocean Information Services (INCOIS). Significant Wave Height (SWH) measurements from SARAL/AltiKa, Jason-2 and Jason-3 altimeters were assimilated using Optimal Interpolation technique. The impact of altimeter DA towards improving reliability predictions is evaluated by validating forecasted parameters with buoy observations. showed considerable improvement predictions. SWH forecast northern region improved up to ~15 % first 24 h period. due correction swell forecast, which persists throughout For wind-sea was less visible (~4–6% lead time h), as it primarily driven local wind fields. positive on further established considering surge event, named Kallakkadal.