Thursday, August 13, 2009

India Hopes for Rain, and an Accurate Forecast

The India Meteorological Department has a spotty record in predicting the all-important monsoon rains. It is up to H.R. Hatwar, a slight, gray-haired man who sits behind a large desk with maps and charts scattered around his computer, to try to improve the forecasts that India's 600 million farmers rely on to plan their crops.

"No prediction is 100% accurate anywhere in the world," he says, promising the 130-year-old institution is "doing all it can to improve its overall forecast."

This year, the department predicted near-normal rainfall; it later adjusted expectations to below normal, and on Monday, more than halfway into a June-September monsoon season that has been so dry that five states have declared drought, India's official weather forecaster said it expected monsoon-season rainfall to be "deficient."

Peter Webster, a professor at the School of Earth and Atmospheric Sciences at Georgia Institute of Technology in Atlanta, says India would give farmers a better sense of when they need to sow their crops if the government dropped its focus on the monsoon's arrival date and the average national rainfall and instead put its efforts into 20-day forecasts.

In India, it's up to the state or central governments to declare a drought, because it entails contingency planning and relief aid. Mr. Webster says India's national drought declaration in 2002 could have been prevented had the department provided timely 20-day forecasts. "If they had planted in the active period their plants would have survived," he says.

Mr. Hatwar, who is in charge of research at the India Meteorological Department, says he is developing 20-day forecasts and hopes to begin issuing them in a year or two. Such extended-range forecasts require advanced computing power that the department is only beginning to put in place, he says. For now, it relies on insufficient data and outdated equipment that requires measurements be taken manually.

It's hard to overstate the importance of the monsoon to India and the national obsession about exactly when it will make landfall (always in the southern state of Kerala, almost always in early June). Agriculture makes up nearly 18% of national gross domestic product, according to Morgan Stanley. Most farmers, without the benefit of irrigation, have just the annual June-to-September rains to water their fields.

A weak rainfall can hurt crop output, drinking-water supply, power generation and consumer demand -- and add another obstacle to government efforts to improve the rural economy as a key to sustained GDP growth.

Citigroup economist Rohini Malkani estimates that an insufficient monsoon could shave close to two percentage points off annual growth.

Almost 80% of the country is under the threat of drought, Agriculture Minister Sharad Pawar said this week.

Finance Minister Pranab Mukherjee said Tuesday he's still optimistic the economy can grow at the earlier estimate of over 6% in the fiscal year ending March 2010. "There is no point in pressing the panic button. This country has the capability of handling a drought situation," he said.

India's Ministry of Earth Sciences recently approved $620 million to be spent over five years to modernize and upgrade weather technology.

With the additional funding, Mr. Hatwar says his department plans to set up 1,000 automatic weather stations -- there are now 125. He says it will also have another 2,000 stations to measure precipitation. The new devices, which relay data by satellite, will help him make better predictions, he says.

Mr. Webster of Georgia Tech says the department will have to change its statistical model, too, complaining it has used the same one more than 50 years. "The basic problem of the India Meteorological Department is that they are mired in the past," he says. Mr. Hatwar defends his model, noting that it has accurately gauged the country's average rainfall for most years.

The British set up the department in 1875. In the early days, it gathered measurements of rainfall and temperature by telegram, the same way it sent flood and drought warnings. Now, information is relayed via satellite, and forecasts are delivered by radio and television.

A mathematician by training, Mr. Hatwar, 59 years old, stumbled into meteorology by accident. In 1972, he gave a paper on fluid mechanics at the prestigious Indian Institute of Science in Bangalore. His mentor, impressed with his work, suggested he enroll in the institute's doctoral program, after which he joined the Meteorology Department in 1977, where he has remained.

Back then, he pored over weather charts made by hand from data received from Russian satellites.

Today, Mr. Hatwar studies computer-generated charts and satellite images of the monsoon. "A lot of progress has been made," he says.

1 comment:

  1. Isn't the lack of monsoonal rain a direct consequence of the Asian Brown Haze in the northern reaches of the Indian Ocean?
    After all,INDOEX 1999 - the discoverers of the haze, forecasted the cooling of the equatorial waters, covered by the haze, would upset global hydrology due to decreased evaporation.
    Therefore, a lower rate of precipitation will result while the haze persists.
    Perhaps authorities should consider taking action to rid the ocean of this pollution.

    ReplyDelete