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Strong Monsoons reversing India’s 50-year Dry Spell: Study

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Low lying areas, patches of roads, paddy fields and several houses have been inundated by the rain water in Tripura. VOA

BOSTON, July 25, 2017: Indian summer monsoons have strengthened over the past 15 years, reversing a 50-year dry period during which northern and central India received relatively little rainfall, an MIT study has found.

Indian summer monsoons bring rainfall to the country each year between June and September.

Researchers found that since 2002 a drying trend has given way to a much wetter pattern, with stronger monsoons supplying much-needed rain, along with powerful, damaging floods, to the populous north central region of India.

A shift in India’s land and sea temperatures may partially explain this increase in monsoon rainfall, according to the study published in the journal Nature Climate Change.

Researchers note that starting in 2002, nearly the entire Indian subcontinent has experienced very strong warming, reaching between 0.1 and 1 degree Celsius per year. Meanwhile, a rise in temperatures over the Indian Ocean has slowed significantly.

According to Chien Wang, a senior research scientist at Massachusetts Institute of Technology (MIT) in the US, this sharp gradient in temperatures – high over land, and low over surrounding waters – is a perfect recipe for whipping up stronger monsoons.

“Climatologically, India went through a sudden, drastic warming, while the Indian Ocean, which used to be warm, all of a sudden slowed its warming,” Wang said.

“This may have been from a combination of natural variability and anthropogenic influences, and we are still trying to get to the bottom of the physical processes that caused this reversal,” he said.

The Indian monsoon phenomenon is the longest recorded monsoon system in meteorology, researchers said.

From yearly measurements, scientists had observed that, since the 1950s, the monsoons were bringing less rain to north central India – a drying period that did not seem to let up, compared to a similar monsoon system over Africa and East Asia, which appeared to reverse its drying trend in the 1980s.

However, researchers found that India has already begun to reverse its dry spell.

The team tracked India’s average daily monsoon rainfall from 1950 to the present day, using six global precipitation datasets, each of which aggregate measurements from the thousands of rain gauges in India, as well as measurements of rainfall and temperature from satellites monitoring land and sea surfaces.

Between 1950 and 2002, they found that north central India experienced a decrease in daily rainfall average, of 0.18 millimetres per decade, during the monsoon season.

To their surprise, they discovered that since 2002, precipitation in the region has revived, increasing daily rainfall average by 1.34 millimetres per decade.

“The Indian monsoon is considered a textbook, clearly defined phenomenon, and we think we know a lot about it, but we do not,” Wang said. (IANS)

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Scientists Prepare To Explore Uncharted Indian Ocean

The mission’s principal scientist, Lucy Woodall of Oxford University, said the researchers expect to discover dozens of new species.

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Indian Ocean
In this image taken from drone video, the Ocean Zephyr is docked in Bremerhaven, Germany, Wednesday Jan. 23, 2019. VOA

Scientists prepared Thursday to embark on an unprecedented, years-long mission to explore the Indian Ocean and document changes taking place beneath the waves that could affect billions of people in the surrounding region over the coming decades.

The ambitious expedition will delve into one of the last major unexplored frontiers on the planet, a vast body of water that’s already feeling the effects of global warming. Understanding the Indian Ocean’s ecosystem is important not just for the species that live in it, but also for an estimated 2.5 billion people at home in the region — from East Africa, the Arabian peninsula, South and Southeast Asia.

The Nekton Mission, supported by over 40 organizations, will conduct further dives in other parts of the Indian Ocean over three years. The research will contribute to a summit on the state of the Indian Ocean planned for late 2021.

The Ocean Zephyr is preparing to leave Bremerhaven, Germany, on the first leg of trip. Researchers will spend seven weeks surveying underwater life, map the sea floor and drop sensors to depths of up to 2,000 meters (6,560 feet) in the seas around the Seychelles.

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FILE – An undated and unplaced handout photo obtained from the Australian Transport Safety Bureau (ATSB) on Dec. 3, 2015, shows Havila Harmony, one of three ships scouring the southern Indian Ocean for the remains of missing Malaysia Airlines flight MH370. (VOA)

Little is known about the watery world below depths of 30 meters (100 feet), which scientists from Britain and the Seychelles will be exploring with two crewed submarines and a remotely operated submersible in March and April.

Ronny Jumeau, the Seychelles’ ambassador to the United Nations, said such research is vital to helping the island nation understand its vast ocean territory.

While the country’s 115 islands together add up to just 455 square kilometers (176 sq. miles) of land — about the same as San Antonio, Texas — its exclusive economic zone stretches to 1.4 million square kilometers (540 million square miles) of sea, an area almost the size of Alaska.

Jumeau said the Seychelles aims to become a leader in the development of a “blue economy” that draws on the resources of the ocean. The archipelago relies on fishing and tourism, but has lately also been exploring the possibility of extracting oil and gas from beneath the sea floor.

“Key to this is knowing not only what you have in the ocean around you, but where it is and what is its value,” he said. “It is only when you know this that you can properly decide what to exploit and what to protect and leave untouched.”

Indian ocean
Gunner Richard Brown (L) of Transit Security Element looks through binoculars as he stands on lookout with other crew members aboard the Australian Navy ship HMAS Perth as they continue to search for missing Malaysian Airlines flight MH370 in this picture released by the Australian Defence Force April 10, 2014. 

“Research expeditions such as the Nekton Mission are therefore vital to help us fill those gaps and better know our ocean space and marine resources to make wise decisions in planning the future of our blue economy,” Jumeau added.

The island nation of fewer than 100,000 people is already feeling the effects of climate change, with rising water temperatures bleaching its coral reefs.

“Our ocean is undergoing rapid ecological transformation by human activities,” said Callum Roberts, a marine conservation biologist at the University of York, England, who is a trustee of the mission.

“Seychelles are a critical beacon and bellwether for marine conservation in the Indian Ocean and globally,” he said.

Also Read: Communication of Coral Eating Starfish can save Coral Reefs: Scientists

The mission’s principal scientist, Lucy Woodall of Oxford University, said the researchers expect to discover dozens of new species, from corals and sponges to larger creatures like types of dog-sharks.

The Associated Press is accompanying the expedition and will provide live underwater video from the dives, using new optical transmission technology to send footage from the submarines to the ship and from there, by satellite, to the world. (VOA)