植被气孔阻抗对区域气候影响的数值试验

Numerical experiments of stomatal resistance variation effects on regional climate

应用区域气候模式RegCM3,单向嵌套NASA/NCAR全球环流模式CAM3.0的输出结果,模拟1992—1997年不同气候背景下,植被气孔阻抗变化对鄱阳湖流域地表水循环过程和地面热量平衡的影响。结果表明,在现代气候条件下,气孔阻抗加倍导致年平均温度增加了0.33℃(1.93%),降水减少了0.23 mm/d(2.4%);在CO2加倍的未来情景下(1)气孔阻抗不变时,平均温度增加了1.69℃(9.96%),降水增加了0.83 mm/d(8.6%),(2)气孔阻抗加倍时,年平均温度增加了2.02℃(11.9%),降水增加了0.68 mm/d(7.1%)。总的看来,气孔阻抗加倍的放大了CO2浓度增加(即温室效应)带来的影响。

Using a regional climate model（RegCM3） which is nested in one-way mode within the NASA/NCAR finite volume element CAM3.0,the effects of stomatal resistance variation on the surface hydrology and heat balance over Poyang Lake Basin is simulated by employing the present-day climate from 1992 to 1997 and doubled atmosphere CO2 concentrations.The result shows that the doubled stomatal resistance in the present climate results in an increase in the annually averaged surface air temperature of 0.33 ℃（1.93%）and a reduction in annually averaged precipitation of 0.23 mm（2.4%）.If both the atmospheric CO2 content and the stomatal resistance are doubled,the regional response of surface air temperature and precipitation are increase in 2.02 ℃（11.9%） and 0.68mm/d（7.1%） compared with 1.69 ℃（9.96%） and 0.83mm/d（8.6%） if CO2 is doubled but stomatal resistance remains unchanged as in the usual ＂greenhouse＂ experiment.Overall,the impact of doubling stomatal resistance can be as large as the effect of doubling atmospheric CO2.