Ocean General Circulation Models are routinely used for operational ocean forecasting and reanalysis on global or regional scale throughout the world. Various programs like Bluelink FOAM, Mercator, TOPAZ are using various models viz., MOM, NEMO, HYCOM for operational forecast of the ocean. In the lines of international efforts of the operational ocean forecasting, INCOIS also has been carrying out of

ocused research towards developing an operational forecast system for the Indian Ocean. Regional Ocean Modeling System (ROMS) was setup and customized for the Indian Ocean domain after conducting extensive inter-comparison experiments. Initially, ocean forecasts (sea surface temperature and currents, mixed layer depth and depth of thermocline) were provided at spatial resolution of 25 km x 25 km. Due to the limitation of model, these forecasts were valid and only for the open ocean where the water depths are more than 150 m. These forecasts, however, were well received by the user community, particularly by the Indian Navy. Recently, the model was modified using improved parameterization and higher resolution (1/8 deg x 1/8 deg resolution). These improvements allowed valid forecasts for the open ocean waters beyond 75 m. Moreover, no assimilation of observed data is enabled in this model

Several operational agencies around the world provide seasonal forecasting, which requires near-real-time knowledge of the ocean state. Seasonal forecasting systems are based on coupled ocean atmosphere general circulation models that predict SST and their impact on atmospheric circulation. Many studies highlighted the importance of better oceanic initial condition, particularly the information on the ocean upper thermal structure, on the skill of climate model forecasts at the seasonal scale. The error in upper ocean thermal structure, particularly the SST, strongly influences atmospheric circulation in the coupled model.

a) Objectives

1. (i) To set up data assimilation in 1/8th degree resolution Indian Ocean model and set up the Regional Ocean Modeling System (ROMS) for the coastal waters around the Indian subcontinent at a horizontal resolution of 1/36o including tides and boundary conditions from basin wide Indian Ocean model, set up of high resolution WRF model forced with atmospheric boundary conditions to force the high resolution ROMS and SWAN, set up of WAVEWATCH III for the Global Oceans (at 1o resolution), Indian Ocean ( at 0.5o resolution), Arabian Sea and Bay of Bengal (at 0.25o resolution), set up of SWAN the coastal waters along the Indian subcontinent at 1/20o resolution forced by the atmospheric forecast from the high resolution WRF model, Couple the SWAN with WAVEWATCH III model.
2. Forecast surface chlorophyll concentration in the Indian Ocean on short time scales using ROMS-NPZD model set up.
3. Provide ocean reanalysis (1979 to present) products for the global ocean with unique historical data from Indian Ocean region at 10 km resolution using a MOM P4 global model with capabilities of data assimilation.
4. Establish an oil spill modeling and trajectory forecast system in operational mode

b) Participating Institutions:

Indian National Centre for Ocean Information Services, Hyderabad.

c) Implementation Plan

The high resolution forecasts of ocean parameters (waves, currents, SST, etc) near the coast and the seas around India has become necessary for safe navigation and other marine activities. To meet this requirement, ocean models with capabilities in data assimilation will be developed and set up covering smaller domains at finer resolutions.

Expertise on ocean data assimilation, which is minimal in the country, will be developed through the induction of young researchers and training them through collaborations with institutes/universities in other countries.

The forecasts of the ocean on daily basis will be done interpreting the information emerging from the high resolution models.

d) Deliverables:

Daily forecasts of ocean parameters (surface and sub-surface) using high resolution ocean models with data assimilation capabilities.

High resolution SST data for the generation of PFZ advisories on cloudy days.

e) Budget:

57 crores

(Rs. In crores)