El Nino, monsoon delinked to rainfall deficit

Hyderabad:  A strong El Nino has been predicted for this year, which governments are warning could result in reduced rainfall and drought. But new research studies claim there is no “one-to-one relationship” between El Nino and deficient or excess monsoon years.

El Nino is a band of inconsistent or unusual warm ocean water temperatures that periodically develops off the Pacific coast of South America and affects weather patterns in many parts of the world.

The El Nino effect is felt in certain years. The years when El Nino is strong are often associated with reduced rainfall or even drought.
Union finance secretary Arvind Mayaram has said that the government is alert and cautious about El Nino affecting the awaited southwest monsoon, the most important source of rainfall for many parts of the country including Andhra Pradesh.

However, according to a new study published by a team of experts, including former IMD Hyderabad chief, Professor M. Satya Kumar, there is no direct relation between the El Nino effect and rainfall. Professor Satya Kumar and his team analysed rainfall deficient and excess years from 1951.

“There is no direct correlation between southwest monsoon and El Nino. Even during some really bad El Nino years, the monsoon was good,” said Prof Satya Kumar.
Scientists say that even if this year is  an El Nino year, there is no need to panic.

Dr A.K. Jaiswal, scientist at IMD and co-author of the study, said, “We cannot straightaway rule out  the impact El Nino have on the  southwest monsoon. El Nino has been observed only since about 1920 and whatever relation it had with southwest monsoon has weakened a lot.”

Scientists say that even during El Nino years, like 1994, strong cold fronts brought good rainfall. A cold fronts is the transition zone where a warmer air mass is replaced by a cold mass of air in the upper atmosphere causing a pressure difference. “This year also, we don’t see any El Nino impact on rainfall,” Dr Jaiswal said.