tailieunhanh - Báo cáo " Variation of some atmospheric circulation factors affecting Vietnam climate "

More and more evidence of global climate warming, sea level rise, droughts, floods and climate extremes are recorded. In Vietnam, the manifestation of climate change (CC) is often considered as changing the level and trend of variation of main climatic elements and sea level. However, Vietnam climate influenced by the characteristics of atmospheric circulation in the Earth climate system. This paper presents expression of some characteristics of regional (the expanded East Asia area: 100S - 500N; 600E - 1600E) atmospheric circulation affecting Vietnam climate, including: surface pressure, zonal circulation indices (Iς); meridional circulation indices (Iλ); Cold. | VNU Journal of Science Earth Sciences 27 2011 107-111 Variation of some atmospheric circulation factors affecting Vietnam climate Nguyen Van Thang Vietnam Institute of Meteorology Hydrology and Environment 23 62 Nguyen Chi Thanh Hanoi Vietnam Received 2 March 2011 received in revised form 15 March 2011 Abstract. More and more evidence of global climate warming sea level rise droughts floods and climate extremes are recorded. In Vietnam the manifestation of climate change CC is often considered as changing the level and trend of variation of main climatic elements and sea level. However Vietnam climate influenced by the characteristics of atmospheric circulation in the Earth climate system. This paper presents expression of some characteristics of regional the expanded East Asia area 100S - 500N 600E - 1600E atmospheric circulation affecting Vietnam climate including surface pressure zonal circulation indices Ic meridional circulation indices IZ Cold front frequency CF in the North of Viet Nam. The numbers of tropical cyclone over the East Sea and affecting Vietnam are mentioned in other studies. Changes in atmospheric circulation over the area are reflected by the differences of regional atmospheric circulation characteristics values between the recent period 1991-2007 and the study period 1960-2007 mentioned above. Keywords variation atmosphere circulation Vietnam climate. 1. Changes in surface pressure . The annual mean surface pressure On the map of East Asia expansion the average surface pressure of the study period 1960-2007 as well as the recent period 19912007 are under control of high pressure over the Eurasian continent HPEA with 1020hPa in the northwest low pressure over India LPI with below 1010hPa in the Southwest low pressure Aleusian LPA with below 1014hPa in the northeast the subtropical Pacific high pressure SPHP with 1016hPa in the southeast and equatorial low pressure ELP with 1010hPa in the south Figure 1 . Tel. 84-4-38359415. E-mail .