Global warming could delay, weaken monsoons: studyGlobal warming global warming, the gradual increase of the temperature of the earth's lower atmosphere as a result of the increase in greenhouse gases since the Industrial Revolution. could delay the start of the summer monsoon by five to 15 days within the next century and significantly reduce rainfall in much of South Asia This article is about the geopolitical region in Asia. For geophysical treatments, see Indian subcontinent. South Asia, also known as Southern Asia , a recent study has found. Rising global temperatures will likely lead to an eastward shift in monsoon circulation which could result in more rainfall over the Indian Ocean Indian Ocean, third largest ocean, c.28,350,000 sq mi (73,427,000 sq km), extending from S Asia to Antarctica and from E Africa to SE Australia; it is c.4,000 mi (6,400 km) wide at the equator. It constitutes about 20% of the world's total ocean area. , Myanmar and Bangladesh but less over Pakistan, India and Nepal, the study found. It could also result in longer delays between rainy seasons and intensify the risk of deadly floods by leading to a significant increase in average rainfalls in some coastal areas of western India, Sri Lanka Sri Lanka (srē läng`kə) [Sinhalese,=resplendent land], formerly Ceylon, ancient Taprobane, officially Democratic Socialist Republic of Sri Lanka, island republic (2005 est. pop. and Myanmar. That could have a major impact on agriculture, human health and the economies of the region, warned study author Noah Diffenbaugh. "Almost half of the world's population lives in areas affected by these monsoons, and even slight deviations from the normal monsoon pattern can have great impact," said Diffenbaugh, interim director of Purdue University's Climate Change Research Center. "Agricultural production, water availability and hydroelectric power hydroelectric power: see power, electric; water power. hydroelectric power Electricity produced from generators driven by water turbines that convert the energy in falling or fast-flowing water to mechanical energy. generation could be substantially affected by delayed monsoon onset and reduced surface runoff Surface runoff is a term used to describe the flow of water, from rain, snowmelt, or other sources, over the land surface, and is a major component of the water cycle.[1][2] ." The atmospheric conditions that lead to reduced rain also can lead to intensification of extremely hot conditions, said lead author Moetasim Ashfaq, a graduate student at Purdue. "In the past when we have seen extremely hot days, we have observed a similar circulation anomaly," Ashfaq said in a statement. "These circulation changes decrease moisture flow over the land, and we see longer periods without rain, along with hot conditions." Ashfaq used a high-resolution climate model to map how global warming will affect the complex topography of South Asia by recreating the monsoon season of past years. He found that increasing temperatures strengthen some aspects of large-scale monsoon circulation but weaken the fine-scale interactions of the land with the moisture in the atmosphere. "Even with a strong monsoon system, if circulation changes enough to change where and when rain is delivered, then that could have an impact that has not been captured in the large-scale evaluations," Ashfaq said. The study was published in the January issue of the peer-reviewed journal peer-reviewed journal Refereed journal Academia A professional journal that only publishes articles subjected to a rigorous peer validity review process. Cf Throwaway journal. Geophysical Research Letters Geophysical Research Letters is a publication of the American Geophysical Union. GRL is the organization's only letters journal. Since its introduction in 1974, GRL has published only short research letters, typically 3-5 pages long, which focus on a specific discipline or . 
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