摘要
使用RegCM2区域气候模式 ,进行了CO2 加倍对中国区域气候影响的数值试验 ,对西北地区进行了重点分析 .结果表明 ,在CO2 加倍的情况下 ,西北地区的气温将明显升高 ,年平均升高值为 2 .7℃ ,高于全国平均变化 .同时降水也将明显增加 ,平均增加率达到 2 5 % ,远高于全国平均 ,增加率的数值大小依次为冬季、春季、秋季和夏季 .
Climate change due to greenhouse effects (2×CO 2) over China, with focus on Northwest China, is simulated by RegCM2 regional climate model (RCM). The model has a horizontal grid point spacing of 60 km and 16 vertical layers, and is nested to a global coupled ocean-atmosphere model (CSIRO R21L9 AOGCM). Driven by lateral boundary conditions from the GCM, both control (1×CO 2) and sensitive (2×CO 2) experiments of the RCM have been run for 5 years respectively. Model outputs are interpolated in 34 stations in the region for convenience of analysis. Results of control run of the RCM indicated that it has a better capability in reproducing present climate in both the whole China and Northwest China than that of the GCM. It reproduced the fine scale structure of air surface temperature ( T s) caused by small topography fluctuations, and lowered down the over-estimated precipitation ( P r) by the GCM. The annually averaged spatial correlation coefficient of the monthly mean T s and P r between the RCM simulation and observation are 0.80 and 0.85, respectively. Results of sensitive experiment by the RCM with 2×CO 2 showed a remarkably warming over Northwest China due to greenhouse effect. In Northwest China, mean T s will increase 2.7 ℃, higher than that in the whole China (2.5 ℃). The warming is higher in winter and spring, about increasing 3.0 ℃. Rising of T s can be noticed in all the 12 months of a year. The summer daily maximum temperature also increases in Northwest China, with an average increasing of 3.1 ℃, higher than the average over the whole country, 2.0 ℃. While the winter daily minimum temperature raises 1.6 ℃, near the average over the whole country, 1.7 ℃. More rainfall may also be expected over the region under the greenhouse effect. Increasing rate of annual P r is usually greater than 20% in most of Northwest China, and 30% or more in some places. The mean P r increase is 25 % in Northwest China, much higher than that averaged over the whole China (12 %). Increasing rates of P r follow the order of winter, spring, autumn and summer. The P r increase is found in all months, except for September, when a slightly decrease appears. T s and P r change by month is also given in this paper for some representative stations in different parts of Northwest China. The simulated change of T s and P r under 2×CO 2 showed some similarities with observation in the recent years.
出处
《冰川冻土》
CSCD
北大核心
2003年第2期165-169,共5页
Journal of Glaciology and Geocryology
基金
中国科学院知识创新工程重大项目 (KZCX1 10 0 6)
国家重点基础研究发展规划项目 (G19980 40 90 0 )
国家杰出青年基金项目 (4 0 12 5 0 )资助
