PRECIS模式对宁夏气候变化情景的模拟分析*

使用英国Hadley气候中心区域气候模式PRECIS,分析了B2温室气体排放情景下,相对于气候基准时段1961~1990年宁夏2071~2100年(2080s)地面气温、降水量等的变化。结果表明:PRECIS模式能够很好地模拟宁夏气温的分布特征,对夏季最高气温的模拟效果好于冬季最低气温;较好地模拟出了宁夏降水南多北少的空间差异特征,且对夏季降水的模拟能力明显强于年均降水和冬季降水。相对于气候基准时段, 在B2情景下,2080s宁夏年平均、冬季和夏季平均气温均明显上升,宁夏北部和南部的部分地区气温上升幅度最大,夏季平均气温和最高气温上升幅度大于冬季平均气温和最低气温;未来宁夏年、冬季和夏季平均降水较基准时段均有所增加,但降水随年代际却呈减少趋势,由于气温和降水的气候变率加大,2080s宁夏出现高温、干旱、洪涝等异常天气事件的可能性增大。

SIMULATION OF CLIMATE CHANGE SCENARIO DURING 2071~2100 IN NINGXIA BY PRECIS

By the simulation of a regional climate model (PRECIS) driven by the higher-resolution HadAM3H obtained from the Hadley Centre of the United Kingdom and based on data of the baseline (1961~1990), changes in surface air temperature and precipitation under SRES B2 scenario of 2071~2100 in Ningxia Province are predicted. Results show that PRECIS can reproduce well the spatial distribution of surface air temperature in Ningxia. The simulation of maximum temperature in summer is better predicted than that of minimum temperature in winter. The spatial distribution of south-to-north increase in precipitation in the region can also be simulated by PRECIS, while the precipitation simulation in summer is much better than that for the annual mean and in winter. During 2071~2100, there might be a significant warming either in annual, or in summer and winter. Greater warming is simulated in northern and southern Ningxia. Increase in mean and maximum temperature in summer might be significantly larger than in winter. General increase of precipitation is simulated in Ningxia. But a decadal decreasing trend of precipitation has been also predicted. Significant variability in temperature and precipitation predicted might indicate more frequent occurrence of some disaster events, e.g. drought and flood.In general speaking, the PRECIS climate model system has higher ability on simulating of temperature in Ningxia Province, while the simulating of precipitation is basically exactable. Hence the model would objectively reflect future climatic change scene of Ningxia. On the other hand, we should note that future climate scene would have large incertitude because factors influencing climate change are extremely complex and the model is not yet perfect, for example, there has been only B2 SRES scenario and the effect of increasing greenhouse gas hasn't been considered. More work sould be done in the future.