How stop on air travel has partially handicapped IMD

The shutdown of air traffic has in a way handicapped the India Meteorological Department (IMD) which apart from other mediums also relies on aircraft to help it in weather prediction, reported The Hindu.

This comes after the Centre which had suspended international flights in mid-March, completely grounded domestic flights after the announcement of a 21-day lockdown starting March 25, in view of the coronavirus situation.

The IMD will now depend on traditional statistical forecast system to predict weather conditions.

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The department has, however, clarified that the annual monsoon forecast is scheduled for issued in mid-April as usual.

Aircraft collect data about temperature and wind speed in the upper stratums and share it with meteorological agencies across the world. This data in turn is used in dynamical models, which can forecast weather three days to three weeks ahead.

Talking to The Hindu DS Pai, chief forecaster at IMD Pune, said the weather inputs received from aircraft helps the dynamical models, run on super computers, determine their initial conditions. He, however, says that the disruption will not affect the monsoon forecast, as it is a long-term forecast.

Data from aircraft also helps to warn about developing thunderstorms or changes in temperature.

“There are mathematical fixes that can be used to compensate for this. However, a lack of data for a prolonged period of time is a big loss for calculating weather trends and future climate patterns,” Pai said.

In the absence of sufficient data, IMD will go back to its traditional statistical forecast system which is developed on the basis of historical data.

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Limited land-based observations due to lack of manpower, has also limited options for the agency.

The report, however, says that India has a long way to go to perfect its dynamical models, to enable scientists to predict a drought or extreme changes in monsoon rainfall.