Missing Monsoon
Listen in RealAudio
Email your weather question

The year was 1792, the place was India, and the event was the opening of the first Western-style scientific observatory in Asia. Sir Charles Oakley launched the Madras Observatory in eastern India, with the goal of promoting astronomy. Indeed, it was a great time for star-gazing as clouds and rainfall were sparse. Why? Because that year, the most reliable rain system on earth, the Indian monsoon, was in the midst of a six-year hiatus. I'm Dave Thurlow for the Weather Notebook.

What was good for astronomy was awful for the people of India. In that one year alone, more than half a million people died from famine in the absence of the usual summertime rains. It was among the worst droughts on record for India.

Some of the dust that flew through the air during that tragic time has just recently been uncovered in a Himalayan glacier. A team of glaciologists is analyzing an ice core that, just like tree rings, leaves clues about past climate, They found huge increases in the amount of chlorine and dust trapped in the ice during years when the monsoon failed. With this researchers could isolate major droughts going back to the 1200's, but nothing as bad as in the 1790s.

Believe it or not, you can probably blame El Niño for this one, at least in part. It's now clear that the Indian monsoon is weaker during El Niño, thanks to the changes in circulation triggered across the whole Pacific by the warmer ocean temperatures off Peru. Of course, in 1792, nobody--not even Sir Charles Oakley--could have dreamt that an ocean pattern thousands of miles away could bring either bounty or misery to the people of India.