NEW DELHI: The India Meteorological Department (IMD) will make necessary amendments to its existing climate models for better prediction in the future as its climate forecast system is ill-equipped to gauge crucial oceanic phenomena owing to which it had to revise its prediction for rainfall from the Southwest Monsoon from "above normal" to "normal".
M Rajeevan, Secretary, the Ministry of Earth Sciences said the IMD currently uses the National Centers for Environmental Prediction (NCEP) Climate Forecast System Version 2 (CFSv2), procured from the United States to understand oceanic patterns. The system was modified to suit IMD'S requirements.
As per IMD's initial forecast, rainfall from the Southwest Monsoon was expected to be "above normal". September was expected to receive "excess" rainfall, but that did not happen.
This, Rajeevan said was primarily due to La Nina, an oceanic phenomenon linked to cooling of Pacific waters resulting in a better monsoon in the Indian sub-continent. The IMD had expected a "full-blown" La Nina, which did not occur, he explained.
"We don't understand the Indian Ocean processes well and have very fewer observations. The dynamics are different from Atlantic and Pacific Oceans. We need to have a lot of observations and start doing it," Rajeevan said.
He said changes will be made to the CFSv2 model to better understand such patterns as even minor changes in the sea surface temperature makes a significant impact on the monsoon. "Changes in the Indian Ocean are very small, but these can make a big difference," he observed.