Extreme climatic events over Vietnam from observational data and RegCM3 projections

• Published in: Climate research Vol. 49; no. 2; pp. 87 - 100
• Main Authors: Ho, Thi-Minh-Ha, Van-Tan, Phan, Le, Nhu-Quan, Nguyen, Quang-Trung
• Format: Journal Article
• Language: English
• Published: Inter-Research 13-10-2011
• Subjects: Climate change; Climate models; Climatic zones; Climatology; Cyclones; Marine; Precipitation; Rain; Rainy seasons; Seasons; Tropical regions; ISEW, South China Sea; ISW, Bangladesh, Bengal Bay; ISEW, Vietnam
• ISSN: 0936-577X; 1616-1572
• DOI: 10.3354/cr01021

Extreme climatic events, including hot days, cold nights and heavy rainfall days, were analysed for 7 climatic sub-regions in Vietnam, based on historical observed data and climate projections of the International Center for Theoretical Physics regional climate model version 3 (RegCM3). Firstly, historical observed data sets covering 1961–2007 were analyzed to detect extreme events and their decade-by-decade trends. Extreme events and their changes are quite different over the 7 sub-regions, owing to their different local climate. Secondly, the extremes of each sub-region detected from the simulation of RegCM3 for the baseline period 1980–1999 were applied to the projection in the years 2001–2050, based on the IPCC SRES A1B and A2 scenarios, to reveal the changing trend of extremes in the future. The RegCM3 projections indicate that, in general, hot summer days will increase and cold winter nights will decrease as a consequence of global warming. The rainy season heavy rainfall events tend to decrease for all sub-regions except for 2, in northwest and south-central Vietnam. Strong opposite projected changes in precipitation extremes over the southern half of Vietnam seem to be linked to changes in southwesterly air flow from the Bay of Bengal and the number of strong tropical cyclones coming from the South China Sea and the NW Pacific.