El Nino effect behind weak monsoon, says WMO

Rising temperatures in the central and eastern tropical Pacific Ocean, known as El Nino conditions, have contributed to the weak monsoon and drought in India among other factors, said Rupa Kumar Kolli, a senior oceanography analyst with the Geneva-based World Meteorological Organization (WMO).

“The development of a basin-wide El Nino has implications for the expected climate patterns in many parts of the world,” he said, suggesting that regional impacts were provided by respective countries. However, it is difficult to rule out the influence of El Nino over the weak monsoon in South Asia among other factors,” the WMO analyst said.

Kolli said El Nino conditions, which contributed to unusual climatic conditions five years ago in the Americas, were “weaker to moderate in intensity over the tropical Pacific and it is very likely that these will continue at least through the remainder of 2009 and probably into the first quarter of 2010”.

It is observed that El Nino occurs once every five years and the ongoing climatic change has not had much impact on this phenomenon, analysts have said.

Already, the ocean surface and sub-surface in the central and Easter Equatorial Pacific have been substantially warmer during June and July because of a weak basin-wide El Nino. In turn, a rise of 0.5 degree Celsius “can have substantial impact on climate patterns in many parts of the world”, he argued.

“In considering risk management strategies,” he said, it was important to always recognise that many unusual climate patterns and significant climate extremes occur independently of El Nino. But it is important to “review approaches to the incorporation of expectations about regional climate risks within broader risk management strategies”.