A new NASA modelling approach could track the deadliest cyclones before they strike and save countless lives, besides predicting weather more accurately. About 15 percent of the world's tropical cyclones occur in the northern Indian Ocean, but because of high population densities along low-lying coastlines, the storms have caused nearly 80 percent of cyclone-related deaths around the world.
Incomplete atmospheric data for the Bay of Bengal and Arabian Sea make it difficult for regional forecasters to provide enough warning for mass evacuations. In the wake of last year's Cyclone Nargis, one of the most catastrophic on record, a team of NASA researchers re-examined the storm as a test case for a new data integration and mathematical modelling approach.
The researchers compiled satellite data from the days leading up to the May 2 landfall of the storm and successfully "hindcasted" Nargis' path and landfall in Burma. "Hindcasting" means that the modellers plotted the precise course of the storm. Besides, retrospective results showed how forecasters might now be able to produce advance warnings in the Indian Ocean and improve advance forecasts in other parts of the world.
When Nargis hit Myanmar May 2, the storm and its surge killed more than 135,000 people, displaced tens of thousands, and destroyed about $12 billion in property.
Cyclones in the Bay of Bengal - stretching from the southern tip of India to Thailand - are particularly difficult to analyse because of "blind spots" in available atmospheric data for individual storms, as well as the small dimensions of the Bay.
Forecasters from the India Meteorological Department (IMD) and the US Navy's Joint Typhoon Warning Center lack access to the fleet of "hurricane hunting" airplanes that fly through Atlantic storms, and have to rely on remote satellite measurements that can only assess atmospheric and ocean temperatures under "clear-sky," or cloudless, conditions -- not exactly common in the midst of a cyclone, said a NASA release.
These finding were published in the March issue of Geophysical Research Letters.