Featured Research

from universities, journals, and other organizations

Seasonal patterns of tropical rainfall changes from global warming revealed

Date:
April 15, 2013
Source:
University of Hawaii ‑ SOEST
Summary:
Projections of rainfall changes from global warming have been very uncertain because scientists could not determine how two different mechanisms will impact rainfall. The two mechanisms turn out to complement each other and together shape the spatial distribution of seasonal rainfall in the tropics, according to a new study.

Rain clouds form over the tropical ocean.
Credit: Ping Huang

Projections of rainfall changes from global warming have been very uncertain because scientists could not determine how two different mechanisms will impact rainfall. The two mechanisms turn out to complement each other and together shape the spatial distribution of seasonal rainfall in the tropics, according to the study of a group of Chinese and Hawaii scientists that is published in the April 14, 2013, online issue of Nature Geoscience.

Related Articles


The one mechanism, called "wet-gets-wetter," predicts that rainfall should increase in regions that already have much rain, with a tendency for dry regions to get dryer. The second mechanism, called the "warmer-gets-wetter," predicts rainfall should increase in regions where sea surface temperature rises above the tropical average warming.

The team of scientists compared current rainfall in the tropics with future rainfall projections from simulations of 18 cutting-edge climate models forced with a likely scenario of atmospheric greenhouse gas concentrations. They found that rainfall in the models increases more in regions that currently are already wet and decreases slightly in currently dry regions, supporting the wet-gets-wetter mechanism. But they also found evidence for the warmer-gets-wetter mechanism in that the higher the surface temperature in a region, the more the rainfall. By merging the impact from the two mechanisms, they noted that they could account for nearly 80 percent of the variations in the models' projected rainfall changes from global warming.

The complementary action of the two mechanisms is because the pattern of ocean warming induces more convection and rainfall near the Equator, where the temperature warming peaks, and subsidence and drying further away from the Equator, reflecting the warmer-gets-wetter view. But as this band of increased rain marches back and forth across the Equator with the Sun, it causes seasonal rainfall anomalies that follow the wet-gets-wetter pattern.

The wet-gets-wetter mechanism contributes more to the projected seasonal rainfall changes, whereas the warmer-gets-warmer mechanism more to the mean annual rainfall changes.

"Because our present observations of seasonal rainfall are much more reliable than the future sea surface temperatures, we can trust the models' projections of seasonal mean rainfall for regional patterns more than their annual mean projections," says co-author Shang-Ping Xie, meteorology professor at the International Pacific Research Center, University of Hawaii at Manoa and Roger Revelle Professor at Scripps Institution of Oceanography, University of California at San Diego. "This is good news for monsoon regions where rainfall by definition is seasonal and limited to a short rainy season. Many highly populated countries under monsoon influences already face water shortages."


Story Source:

The above story is based on materials provided by University of Hawaii ‑ SOEST. Note: Materials may be edited for content and length.


Journal Reference:

  1. Ping Huang, Shang-Ping Xie, Kaiming Hu, Gang Huang, Ronghui Huang. Patterns of the seasonal response of tropical rainfall to global warming. Nature Geoscience, 2013; DOI: 10.1038/NGEO1792

Cite This Page:

University of Hawaii ‑ SOEST. "Seasonal patterns of tropical rainfall changes from global warming revealed." ScienceDaily. ScienceDaily, 15 April 2013. <www.sciencedaily.com/releases/2013/04/130415182510.htm>.
University of Hawaii ‑ SOEST. (2013, April 15). Seasonal patterns of tropical rainfall changes from global warming revealed. ScienceDaily. Retrieved October 26, 2014 from www.sciencedaily.com/releases/2013/04/130415182510.htm
University of Hawaii ‑ SOEST. "Seasonal patterns of tropical rainfall changes from global warming revealed." ScienceDaily. www.sciencedaily.com/releases/2013/04/130415182510.htm (accessed October 26, 2014).

Share This



More Earth & Climate News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

EU Gets Climate Deal, UK PM Gets Knock

EU Gets Climate Deal, UK PM Gets Knock

Reuters - Business Video Online (Oct. 24, 2014) EU leaders achieve a show of unity by striking a compromise deal on carbon emissions. But David Cameron's bid to push back EU budget contributions gets a slap in the face as the European Commission demands an extra 2bn euros. David Pollard reports. Video provided by Reuters
Powered by NewsLook.com
Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Deep Sea 'mushroom' Could Be Early Branch on Tree of Life

Reuters - Innovations Video Online (Oct. 24, 2014) Miniature deep sea animals discovered off the Australian coast almost three decades ago are puzzling scientists, who say the organisms have proved impossible to categorise. Academics at the Natural History of Denmark have appealed to the world scientific community for help, saying that further information on Dendrogramma enigmatica and Dendrogramma discoides could answer key evolutionary questions. Jim Drury has more. Video provided by Reuters
Powered by NewsLook.com
Raw: Tornado Rips Roofs in Washington State

Raw: Tornado Rips Roofs in Washington State

AP (Oct. 24, 2014) A rare tornado ripped roofs off buildings, uprooted trees and shattered windows Thursday afternoon in the southwest Washington city of Longview, but there were no reports of injuries. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Fast-Moving Lava Headed For Town On Hawaii's Big Island

Fast-Moving Lava Headed For Town On Hawaii's Big Island

Newsy (Oct. 24, 2014) Lava from the Kilauea volcano on Hawaii's Big Island has accelerated as it travels toward a town called Pahoa. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins