区域尺度土地利用/土地覆盖变化对气温日较差的影响

Impacts of Regional-Scale Land Use/ Land Cover Change on Diurnal Temperature Range

利用NCAR CAM4.0模式,针对潜在植被和当代植被两种典型土地覆盖类型,通过平衡态试验探讨土地利用/土地覆盖变化(land use/land cover change,LUCC)对气候的影响。结果表明,LUCC对气温日较差有明显影响。日较差的响应与LUCC变化的区域有紧密的联系。在中纬度,LUCC引起日较差减小,这主要由日最高气温的降低造成。在低纬度东亚地区,日较差的减小主要由日最高气温的降低造成;而在印度半岛,日较差的减小主要由日最低气温的升高决定。这种区域性的差异,主要是由于植被蒸腾和冠层蒸发的作用,LUCC能够显著调节气温日较差的变化。

The NCAR Community Atmosphere Model （CAM4.0） was used to investigate the climate effects of land use/land cover change （LUCC）. Two simulations, one with potential land cover without significant human intervention and the other with current land use, were conducted. Results show that the impacts of LUCC on diurnal temperature range （DTR） are significant. In the mid-latitudes, LUCC leads to a decrease in DTR, which is mainly caused by the reduction in daily maximum temperature. The reduction in DTR in East Asia of the low latitudes is chiefly the result of the decrease in daily maximum temperature, while in the Indian Peninsula, the decrease in DTR is due to an increase in daily minimum temperature. In general, the LUCC significantly controls the DTR change through the changes in vegetation transpiration and canopy evaporation.