CMIP5部分模式气温和降水模拟结果在北半球及青藏高原的检验

Verifications of Surface Air Temperature and Precipitation from CMIP5 Model in Northern Hemisphere and Qinghai-Xizang Plateau

利用北半球和青藏高原的观测资料,通过趋势分析、量值比较及小波分析等方法对已提交历史模拟结果的8个模式进行了比较。结果表明,各模式对北半球气温年变化模拟的较好,一般7、8月气温最高,1月气温最低,不存在相位差问题。各模式模拟的历史气温年际和年代际变化趋势比较一致,气温最大相差2.8℃以上;模拟的1850-2005年气温平均最高和最低值相差可达1.8℃左右;除1个模式外,其余模式都能较准确地模拟出至少有一次气温突变。对北半球降水的模拟,各模式都模拟出了降水的季节变化,但从年际变化趋势来看,4个模式模拟的降水为增大趋势,4个为减小趋势。对青藏高原的模拟,从变化趋势与观测气温的对比来看,8个模式中,除2个模式通过了0.05显著性水平检验外,其余均通过了0.01显著性水平检验;各模式都模拟出了青藏高原的降水中心,但对降水量值的模拟相差较大。

Climate model is a powerful tool for climate change.For future climate change assessment and forecast,climate model is the necessary technique to be assist.CMIP program has been performed to CMIP5 stage,and has been provided the longest and the most extensive database for climate change.This provides the unsubstantiated scientific basis for forecast the future climate change.Before detailed analysis of the simulation results,it is necessary to use the observational data to assess the simulation results,and the relatively good results are chose for analysis.This is benefit for simulation of the credibility and model development and improvement.In this paper,the observations data of Northern Hemisphere and Qinghai-Xizang Plateau were used by trend analysis,value comparison,wavelet analysis,and then simulation results by 8 models were compared.The results show that all models have well simulated at temperature changes in the Northern Hemisphere region.In general,the highest temperature is in July and August,the lowest temperature is in January,and there is no phase problem.All the modes have the consistent results in the interannual and interdecadal changes,but the maximum temperature difference can reach of 2.8 ℃.About the average annual temperature from 1850 to 2005,the difference between maximum and minimum simulation results can up to 1.8 ℃.Besides one model,others can accurately simulate temperature break at least once.About the precipitation simulation in the Northern Hemisphere region,each model can simulate the seasonal changes in precipitation,but the trend show that four models simulate the increasing precipitation and whereas four modes simulate the reduced trend.About the temperature simulation in Qinghai-Xizang Plateau,besides two models have passed the test of confident level of 95%,others have passed the test of confident level of 99%.Each model can simulate the precipitation center of the Qinghai-Xizang Plateau,but precipitation values for each simulation model arequite different.After the comparative analysis,two models areselected for the follow-up study.