青藏高原及铁路沿线未来50年气候变化的模拟分析

The Simulated Result Analyses on Climate Changes over Qinghai-Xizang Plateau and along the Railway in the Coming 50 Years

利用由IPCC数据分发中心(DDC)提供的5个全球海气耦合模式(包括海冰与陆地生态系统)(CCCma,CCSR,CSIRO,GFDL,Hadley)气温及降水的模拟结果,对温室气体排放情景SRES-A2和B2影响下,青藏高原及铁路沿线未来50年气温和降水的变化进行了分析,包括整个青藏高原地区2011-2040年,2041-2070年的温度和降水空间分布特征以及21世纪前50年温度和降水变化的线性倾向等,结果表明:在人类活动引起的温室气体不断增加的情况下,21世纪青藏高原地区的温度将继续增加,在B2排放情景下,2011-2040年年平均温度增暖在高原主体达到1.6℃;2041-2070年,整个青藏高原的温度将上升2.8～3.0℃,A2排放情景下的升温幅度比B2排放情景下略高.对青藏铁路沿线地区各站A2和B2两种排放情景下,每10年平均的温度分析表明,在A2排放情景下,到2050年前后青藏铁路沿线各站的温度增加将是2010年时的2～3倍左右,A2时在 2.56～2.96℃之间,B2时在 2.37～2.65℃之间.对21世纪前50年整个青藏高原地区温度变化的线性倾向的空间分布的分析可知,在A2排放情景下,大部分都在1.5～2.5℃/50a,冬季大部分地区的变暖倾向都在2.0℃/50a以上,有些地区达到2.5℃/50a以上,夏季在2℃/50a左右;B2时青藏高原地区温度变化倾向的分布趋势与A2时基本一致,只是变化的数值偏低约0.5℃.对21世纪青藏高原地区降水变化的预估结果表明,与温度不同,在两种不同的排放情景下,降水的变化较为复杂.总体来说,21世纪前50年青藏高原大部分地区的降水为增加趋势.

The predictions of surface air temperature and precipitation changes over Qinghai-Xizang Plateau and along the railway due to the green house gas effect of human activities in 21^st century was stud- ied based on the simulation results of five atmosphere-ocean coupled AOGCMs models （CCCma, CCSR, CSIRO, GFDL, Hadley）. The trends of temperature and precipitation changes in former 50 years of 21^st century are analyzed, including the distributions of surface air temperature and precipitation changes over Qinghai-Xizang Plateau in 2011-2040 and 2041-2070. Results of the projections showed that the warming is to continue over Qinghai and Xizang by both the scenario SRES-A2 and B2. The warming range is 1.6℃ along Qinghai-Xizang railway in the early century and 2.4-3.4℃ in the middle century. The analyses of every 10 year mean tempeartures show that, for scenario A2, the temperature change along Qinghai-Xizang railway around 2050 years is 2-3 times as against around 2010 years. For A2, the temperature is between 2.56~2.96℃, for B2, between 2.37-2.65℃. The temperature increasing in the winter is more than in the summer. The precipitation will increase in 21^st century.