Monsoon rains covered India the earliest ever in 108 years of official records. India's meteorologists are baffled. The rains have covered all of India in just 12 days when normally it takes 30. Usually it is very hot before early monsoons, but this year was cooler than normal.
However, climatologists studying global warming, have observed that early monsoons correlate with warm Atlantic Ocean temperatures. This year the Atlantic is much warmer than normal.
By NOAA
The earliest Indian monsoon ever, this June, in 108 years of records may be caused by global warming. Global circulation modeling predicts that the Indian monsoon strength will increase with warming global temperatures. Specifically, warmer than normal Atlantic ocean temperatures correlate with early and strong monsoons.
The Director of India's climate center said it's difficult to link this early monsoon to climate change.
The early arrival of the monsoon in Delhi, breaking a 108-year old record, has puzzled weather officials. It punches a hole in the entrenched theory - the hotter it gets, the better the chances of the monsoon.
But this year, the north has been cooler by almost 1.5 degrees centigrade. Yet, it took merely 12 days, instead of 30, for the monsoon to cover most of India.
So is this freak weather? Is it climate change?
''This early onset has really surprised us and we need to do some data analysis as to why it has happened and at present, we do not have much knowledge as to why it has happened,'' said Dr M Rajeevan, Director, National Climate Centre, IMD, Pune.
''We need to do more studies on the monsoon, but it is very difficult to link this situation to climate change,'' he added.
He has a strong point. One weather event is not climate. However, the Atlantic ocean has been warming for years. In 2005 strong warming in the tropical Atlantic led to a record Atlantic hurricane season. This year the strong warming has spread into the temperate and subtropical north Atlantic, while last winter's La Nina cooled the Pacific ocean. The cool Pacific and the warm Atlantic are likely driving the monsoon circulation. Monsoons start late when the Pacific is warmest - in El Nino years.
Research published in Dec. 2006 showed that global warming is increasing monsoon strength.
Global warming is intensifying the monsoon in Central India, according to a study that warns of increasing risk from heavier rains during the season.
The research, published in Science today (1 December), reinforces claims that global warming is boosting the power and number of storms and other extreme weather events across the world.
Heavy monsoon rains in central India between 1981 and 2000 were more intense and frequent than in the 1950s and 1960s, and increased by 10 per cent since the early 1950s. Severe rains doubled over the same period.
At the same time, there were fewer moderate rains, say the team led by B.N. Goswami from the Indian Institute of Tropical Meteorology, Pune, India.
The trends are likely linked to rising global temperatures, Goswami told SciDev.Net.
India's monsoons were stronger in 1950 they were 200 years before in the little ice age. Greenhouse gas caused warming has amplified the trend that started naturally. The strength of the Indian monsoon can be directly tied to the temperature of the north Atlantic ocean.
the researchers compared the Arabian sediment record to iceberg debris that had settled into the floor of the North Atlantic ocean over the same time period. The tiny iron-stained grains found in the sediment provide a record of temperatures in the region spanning from Greenland south to the British Isles.
The records revealed seven intervals of weakened monsoon coinciding with cold spells in the North Atlantic region. The most intense monsoons occurred at times when the North Atlantic was warmest.
"It is satisfying because we now find this same hypothesized link operating through many oscillations in the last 10,000 years," Overpeck says. "But this also leads us to scary implications."
Ocean circulation patterns in the North Atlantic play a key role in global climate, working like a conveyor belt to bring warmth from the tropics to northern latitudes in Europe, Overpeck says.
The earliest monsoon ever recorded is also an indicator that this year's Atlantic hurricane season is likely to be much stronger than normal. The Atlantic Coast waters from Florida to Maryland are very warm this June, raising the risk of intense hurricane landfalls in the coming months.
The early monsoon is already causing massive flooding and many deaths in India.
GUWAHATI/BHUBANESWAR: At least 27 people are feared killed and more than 3 lakh people displaced in the northeast, particularly Assam, with the onset of monsoons. Not just the northeast, but large parts of northern Orissa are also under water, with the army and administration on overdrive to evacuate villagers in the flood-hit parts of the states.
With the Brahmaputra in spate, also under threat is the endangered Majuli, the world's largest river island. The district administration has already dispatched medicines and food and kept motorboats ready to evacuate the islanders in case it goes under. But the worst-hit is Assam's Lakhimpur, where seven persons have died and over 3 lakh people hit.
Approximately 20,000 people are taking shelter in 14 relief camps and 20 temporary shelters in the district. The army is carrying out rescue operations, ferrying people to high-lying areas from roof-tops.