6.2.1 Indian Ocean Modelling and Dynamics (INDOMOD)

Recognising the modelling of ocean and atmosphere forms an integral part for Ocean Information Services, the Indian Ocean Modelling and Dynamics (INDOMOD) has been designed for implementation during the 9th Plan. The INDOMOD project envisages development of a suite of wide range ocean models for operational requirements on ocean state forecast of the seas around India. The primary applications of these models being generated include prediction of monsoon variability, storm surges associated with cyclones, waves, biological productivity and coastal processes. The participating institutes involved with this endeavour are Centre for Mathematical Modelling and Computer Stimulation (C-MMACS), Bangalore; National Institute of Oceanography (NIO), Goa; Indian Institute of Tropical Meteorology (IITM), Pune; Indian Institute of Science, Bangalore; Indian Institute of Technology, Delhi (IIT-D); and Cochin University.

During the year, a study was carried out using National Centre for Medium Range Weather Forecasting (NCMRWF) medium range forecast model and hybrid-coupled models to assess the inter-annual variability of wind stress over Indian Ocean region to improve the forecasting of monsoons. Experiments were also conducted using Modular Ocean Model using satellite and climatologic data to develop a system for experimental Ocean State forecast. Efforts were also underway to develop models to estimate biological productivity leading to experimental forecasting of fishery abundance. Experiments were carried out with storm surge studies and regional wave prediction. Development of a numerical model for coastal tidal circulation useful for water quality studies of coastal areas was completed.

6.2.2 Joint Global Ocean Flux Study - JGOFS (INDIA)

The Department continued implementing the Joint Global Ocean Flux Study (JGOFS-India) programme to estimate the carbon fluxes in the Arabian Sea. The objective of the study is to predict long-term oceanic variability primarily due to climate changes. It is the Indian part of an interdisciplinary core programme of the International Geosphere Biosphere Programme (IGBP) with focus on Central and Eastern Arabian Sea. National Institute of Oceanography (Goa), Physical Research Laboratory (Ahmedabad), Centre for Mathematical Modelling and Computer Simulation (Bangalore) and National Chemical Laboratory (Pune) participated in the programme. The programme started in the year 1998 and field work and analysis were completed in 2000. During the year a completion report was prepared and project was closed. Based on the distribution of physical, chemical and biological properties in the water column of the central and eastern Arabian Sea the following conclusions emerge:

Physical forcing exerts a significant control on the nutrient distribution and primary productivity, convective mixing enhance primary productivity in the northern latitude during winter. Whereas, lateral transport influences biological production in the central Arabian Sea.

Zooplankton abundance is in variance with time and space.

This region is a source of CO2 to the atmosphere, with an average annual flux of ~ 45 Terra gram (Tg). Two other green house gases, CH4 and N2O also efflux from sea to air with annual fluxes of 0.05 and ~1 Tg y -1 corresponding to ~ 0.3 and ~ 10% of their global fluxes.

6.2.3 Bay of Bengal Process Studies (BOBPS)

The general oceanography of the Bay of Bengal & its role in Carbon cycling remained poorly understood. A new programme entitled " Bay of Bengal Process Studies (BOBPS) which is an equivalent of the JGOFS programme in the Arabian Sea, has been launched. The observations under BOBPS project would be carried out in the Bay of Bengal. This is also a multi- institutional programme implemented by National Institute of Oceanography, Physical Research Laboratory, Centre for Mathematical Modelling & Computer Simulation and Goa University with a project duration of three years.

6.2.4 Land Ocean Interaction in the Coastal Zone (LOICZ)

The LOICZ project envisages estimation of fluxes of various elements such as carbon, nitrogen, trace metals and major elements in the land and ocean boundary and its variability for understanding the changes in the coastal zones at regional and global scale particularly with respect to global climate change. The primary objective of the programme is to determine carbon associated elemental fluxes in the coastal areas of India, which are potential contributors to land ocean interaction, with a view to improving the predictive capability of changes of the coastal zones of India. Two typical coastal areas such as Godavari Basin and Eastern Arabian Sea Margin have been considered for undertaking these studies. The institutes associated with the programme are National Institute of Oceanography (NIO), Physical Research Laboratory (PRL), Andhra University, Jawaharlal Nehru University (JNU) and Anna University.

Systematic studies along the west coast of India revealed the occurrence of low oxygen waters during the southwest monsoon and the intervening monsoon months. Prevalence of such conditions favours higher production of nitrous oxide in these waters making these regions potential sources of atmospheric nitrous oxide.

The low oxygen conditions have resulted from very high biological production triggered by nutrient supplies from upwelling and run-off and the presence of low salinity at he surface following the monsoonal freshwater inputs. However, the global warming potential of these regions gets downplayed because of the fact that the sub-oxic waters that sustain high biological activity are also producing very high concentrations of dimethyl sulphide, which is an anti - greenhouse gas.

Studies on the carbon dioxide system in the Mandovi - Zuari estuarine system revealed that partial pressure of carbon dioxide in these waters has far exceeded its atmospheric levels.

To understand the flow of carbon in continental margin sediment traps have been deployed off the central West Coast of India recently (November 2000). Some sediment samples including a few cores have also been collected. The studies under the project started in the year 1998 and expected to conclude by December 2001.