IMD moots 'dynamic' models to forecast monsoon

IMD moots 'dynamic' models to forecast monsoon

The models being developed by the India Meteorological Department (IMD) to attempt a five-year monsoon plan supplements the existing statistics-based systems. South-West monsoon (June-September) rains accounts for an average 75 to 90 per cent of the annual rainfall. The new programme to be given shape from next year will involve various meteorological institutes in the country that will work on the proposed 'National Mission on Monsoon' being undertaken at the instance of the Ministry of Earth Sciences (MoES).

"Use of reliable dynamic models will improve accuracy in weather and monsoon predictions", said Ajit Tyagi, Director General, Meteorology, IMD, at the just-concluded session of South Asian Climate Outlook Forum  (SACOF) here. The IMD officials, who participated in the deliberations, said various international dynamic prediction models would be studied to devise a five-year monsoon forecast plan for India.

The dynamic models--models that put greater emphasis on physics of atmospheric flow and processes--for forecasting monsoon will be in place in addition to the statistics-based ones that are being employed at present. The statistical models are based on correlation of various global and regional parameters. At present, long range forecasting of the monsoon is based on statistical models that are also used for seasonal forecast.

"The dynamic models are more objective and the initial values used in the equations of these models are current weather observations", according to A B Mazumdar, Deputy Director General Meteorology, IMD, Pune. Detailing the proposed 'Monsoon Mission', Tyagi said, "the programme will be initiated from next year and leading meteorological institutions such as Indian Institute of Tropical Meteorology (IITM) and IMD will participate in it."

Precision in the forecasting of South-West monsoon assumes a particular significance for the entire South Asia for its socio-economic impact on the region. Several studies highlight the critical dependence of crop production on monsoon rainfall. The summer monsoon rainfall is also important for hydroelectric power generation and meeting drinking water requirements.