植被变化对2009年云南极端秋旱影响的数值模拟研究

利用Reg CM4模式对2009年云南极端秋旱开展了植被变化数值模拟试验。结果显示：Reg CM4对2009年云南极端秋旱具有较好的模拟能力,能够用于气候极端事件和植被变化气候影响的定量研究。植被退化和荒漠化导致降水减少、气温升高、比湿降低,大气状态更为干热化,试验情景下2009年云南极端秋旱加剧。植被变化导致云南上空700h Pa反气旋型偏差风场和500h Pa高度场异常升高是导致降水量减少的主要原因。荒漠化导致的干热化在范围、强度上都强于植被退化。

Numerical Experiments on the Influences of Vegetation Changes on Heavy Drought in Yunnan during Autumn in 2009

A numerical simulation experiment about vegetation changes is carried out for the extreme autumn drought in 2009 in Yunnan, by using of RegCM4. The results show that the RegCM4 has a better capability of simulating the extreme au- tumn drought in Yunnan, and it can be used for quantitative study on the extreme climate events and the impact of vegetation changes. Vegetation degradation and desertification lead to reduction of precipitation, going up of temperature, going down of specific humidity, and xerotization of atmospheric condition. Under the experimental scenario described, the extreme autumn drought in 2009 in Yunnan is exacerbated. The main cause for the reduction of precipitation is to the abnormal rising of 700hPa anticyclonic deviation wind field and 500hPa geopotential height field, which is resulted from vegetation changes. The xerotization led by desertification is much stronger than that of vegetation degradation in terms of scope and intensity.