Impact of Altimeter Data Assimilation with SSHA in improving the monsoon forecast
Event: 2014 SARAL/AltiKa workshop
Presentation type: Type Oral
NCEP-Coupled Forecast System (CFS) is being implemented as part of the Monsoon Mission project of Government of India (Samir et al., 2013). Global Ocean Data Assimilation (GODAS) is the assimilation module for Modular Ocean Model (ocean component of CFS).The assimilation scheme in GODAS is 3DVAR. For a coupled model like CFS, the accurate forecast of SST is an important factor for an accurate forecast of monsoon. Presently we derive synthetic profiles of Temperature and Salinity using multivariate EOF technique, from the gridded SARAL/ALTIKA measurements of SSHA to obtain an accurate estimate of SST. The multi-mission merged altimetric product (TOPEX/POSIDON, JASON1 & 2) data has been utilized for training purpose and SARAL data is utilized for real time derivation of synthetic profiles. Several experiments are carried out by assimilating only the ARGO profiles, only the synthetic profiles derived from SARAL and a combination of both in-situ ARGO profiles and the synthetic profiles to understand the impact of altimeter assimilation on the Indian summer monsoon forecast and the associated large scale circulation changes. An analysis to study the impact of pacific ocean on the Indian monsoon is carried out.