News / Science & Technology

Scientists Create 700-Year Model of Asian Monsoons

Cloud forests in the mountains of Vietnam's Bidoup Nui Ba National Park contain conifer species, including Po Mu (Fokiena hodginsii), that can live for a thousand years or more
Cloud forests in the mountains of Vietnam's Bidoup Nui Ba National Park contain conifer species, including Po Mu (Fokiena hodginsii), that can live for a thousand years or more

Half the world's population is affected by Asian monsoons, yet the rainy seasons are notoriously hard to predict.  But U.S. researchers have put together a 700-year record of the Asian monsoons they hope will guide forecasters.  

Every summer, India, East Asia, eastern Africa, Indonesia and northern Australia are drenched by moist air masses called monsoons, which are pulled in by a high pressure area over the Indian Ocean and a low pressure area to the south.  

A monsoon will typically begin with no warning sometime during June, July or August, or instead of non-stop rain there may be drought conditions, which can spell disaster for subsistence farmers.

Edward Cook of the Lamont-Doherty Earth Observatory at Columbia University in New York says the complex, interrelated nature of the climate systems across Asia makes monsoons hard to predict.  He says climate records date to 1950, too recent and not detailed enough to be of much use.  

So researchers led by Cook spent more than 15 years traveling across Asia locating trees old enough to provide long-term records.  They measured the rings inside of the trunks of thousands of ancient trees at more than 300 sites.  

The investigators put together a Monsoon Asia Drought Atlas documenting monsoons over a 700-year period, beginning in the 1300s.  

Cook says the tree-ring data indicate periods of wet and dry conditions.

"If the monsoon basically fails or is very weak one year, the trees affected by the monsoon at that location might put on a very narrow ring," explains Cook.  "But if the monsoon is very strong, the trees affected by that monsoon might put on a very wide ring for that year.  So, the wide and narrow ring widths of the tree chronology that we developed in Asia provide us with a measure of monsoon variability."

Armed with such a sweeping set of data, researchers say they now can begin to refine climate computer models to try to predict the behavior of monsoons, according to Cook.

"Because the system is kind of coupled, in other words, there is nothing really truly, completely independent about those areas with respect to monsoon variability, having the information in any given year about the monsoon variability in all those regions at the same time might help us produce a more robust model for explaining how the Asian monsoon system works," he said.

Eugene Wahl is with the U.S. National Oceanic and Atmospheric Administration's paleoclimate branch, which studies weather patterns over the history of the Earth.  

Wahl says the Monsoon Asia Drought Atlas is a major accomplishment, filling in a major data gap on monsoons, which affect the lives of one half of the world's population.

"There has been widespread famine and starvation and human dying in the past in large droughts.  And on the other hand if the monsoon is particularly heavy it can cause extensive flooding.  So, to get a sense of what the regional moisture patterns have been, dryness and wetness over such a long period of time in great detail, I would call it a kind of a victory for paleoclimate science," he said.

An article describing the Monsoon Asia Drought Atlas, and accompanying commentary by Eugene Wahl, is published this week in the journal Science.   

You May Like

India PM Modi's party distances itself from religious conversions

BJP under fire for being slow to rein in hardline affiliate groups allegedly trying to promote a Hindu-dominant agenda by luring Muslims and Christians to convert to Hinduism More

Anti-Whaling Group Found in Contempt of Court

Radical environmentalists who threw acid and smoke bombs at Japanese whalers in the waters off Antarctica continue their campaign to disrupt Japan's annual whale hunt More

UN's Ban Urges End to Discrimination Against Ebola Workers

Ban was speaking in Guinea on the second day of a whistle-stop tour aimed at thanking healthcare workers of the countries at the heart of the epidemic More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Sudan School Becomes Target of Aerial Attacksi
X
December 19, 2014 12:45 AM
The school dropout rate is at an all-time high in Sudan's South Kordofan state because many schools have been destroyed during the three-year civil war between the government and SPLA-N rebel forces. Adam Bailes visited Sudan's Nuba Mountains' region and reports many children are simply too scared to go to school
Video

Video Sudan School Becomes Target of Aerial Attacks

The school dropout rate is at an all-time high in Sudan's South Kordofan state because many schools have been destroyed during the three-year civil war between the government and SPLA-N rebel forces. Adam Bailes visited Sudan's Nuba Mountains' region and reports many children are simply too scared to go to school
Video

Video VOA Reporter Tours Devastated Peshawar School

Islamist militants wearing military uniforms and strapped with explosives attacked a military run school Tuesday in the northwestern Pakistani city of Peshawar. At least 141 people were killed in the horrific attack, most of them young students. VOA reporter Ayaz Gul visited the devastated school and attended the funeral of the principal who courageously tried to save her students from the deadly attack.
Video

Video Nigerians Fleeing Boko Haram Languish in Camp Near Capital

In its five-year effort to impose Islamic law in northeastern Nigeria, the Boko Haram extremist group has killed thousands of people and forced hundreds of thousands to flee. Some of those who ran for their lives now live in squalor on the edges of the capital, Abuja. Chris Stein reports for VOA.
Video

Video Putin Says Russian Economy Will Emerge Stronger

Russian President Vladimir Putin has said his country's sinking economy will not only recover but also become stronger, despite falling oil prices and Western sanctions over Ukraine. VOA's Daniel Schearf reports.
Video

Video Detained Turkish Journalists Follow Teachings of US-Based Preacher

The Turkish government’s jailing of critical journalists has sparked international condemnation and is being seen as an effort to undermine the followers of an ailing Turkish preacher based in the United States. VOA religion reporter Jerome Socolovsky has more.
Video

Video ‘Anti-Islamization’ Marches Increase Tensions In Germany

Anti-immigrant rallies in Germany have been building in recent weeks, peaking Monday night in the city of Dresden where tens of thousands of people turned out to demonstrate against what they call the ‘Islamization’ of the West. Germany has offered asylum to more Syrian refugees than any other country, and this appears to have set off the protests. Henry Ridgwell reports from London.
Video

Video Aceh Rebuilt Decade After Tsunami, But Scars Remain

On December 26, 2004 there was an earthquake in the Indian Ocean so powerful it caused the Earth’s axis to wobble a few centimeters. Onshore on the island of Sumatra, the resulting tsunami was devastating. A decade later, VOA Correspondent Steve Herman reports from Banda Aceh, Indonesia, where although there is little remaining evidence of the physical devastation, the psychological scars among survivors remain.
Video

Video Refugees Living in Kenya Long for Peace in the Home Countries

Kenya is host to numerous refugees seeking safe haven from conflict. Immigrants from Somalia face challenges in their new lives in Kenya. Ahead of International Migrants Day (December 18) Lenny Ruvaga has more for VOA News from the Kenyan capital.

All About America

AppleAndroid