城市化影响着局地与区域气候变化。区域气候模式是探讨城市与环境问题演变机制与城市化气候效应的重要研究手段,然而模式地表参数化方法处理地表参数时难以全面反映下垫面状况,可能影响模拟结果的合理性。因此以卫星数据源为基础,分析了...城市化影响着局地与区域气候变化。区域气候模式是探讨城市与环境问题演变机制与城市化气候效应的重要研究手段,然而模式地表参数化方法处理地表参数时难以全面反映下垫面状况,可能影响模拟结果的合理性。因此以卫星数据源为基础,分析了OPI方法处理下垫面参数导致的偏差,结合其导致的地表辐射收支差异说明不同空间尺度偏差的辐射收支效应,进而通过与CO2排放关联定量分析OPI方法对城市化气候效应的影响。结果发现随着空间尺度的变大,OPI方法导致的城市面积提取误差也在变大,导致城市下垫面转变成了其周边的土地覆盖类型,增强了城市群区域的反照率,降低了城市区域的辐射收支,弱化了城市气候效应。研究发现城市地表单位面积反照率增加0.01相当于减少了2.82kg的CO2排放,京津冀城市群2009年案例分析表明其弱化程度相当于减少了CO2排放2.28×105 t,扩展到中国区域尺度上则相当于减少了1.81×106 t CO2排放。展开更多
An advanced three-level global atmospheric general circulation model has been used to study the summer precipitation anomaly in Northwest China.based on the synoptic fact and the statistical analysis of the precipitat...An advanced three-level global atmospheric general circulation model has been used to study the summer precipitation anomaly in Northwest China.based on the synoptic fact and the statistical analysis of the precipitation,the surface albedo in Northwest China,and the synoptic systems over the Tibetan(Qinghai-Xizang)Plateau.The results show that either the anticyclone intensified over the plateau or the surface alhedo enhanced in Northwest China results in summer precipitation reduction east of Northwest China.Especially.when both of them appear simultaneously,summer precipitation was obviously reduced and severe drought occurred in most areas of Northwest China.Moreover.the simulated difference of precipitation rate of Northwest China is similar to the actural precipitation distribution in Northwest China in 1995,which is the most severe drought year in Northwest China in the past fifty years.So the tendency in drought severity intensified,drought frequency accelerated,drought persistence period extended,and drought areas expanded in Northwest China in recent years is maybe a result of the influences of human activities(e.g.vegetation was reduced,and desertification worsened)on drought circulation pattens over the Tibetan Plateau.展开更多
文摘城市化影响着局地与区域气候变化。区域气候模式是探讨城市与环境问题演变机制与城市化气候效应的重要研究手段,然而模式地表参数化方法处理地表参数时难以全面反映下垫面状况,可能影响模拟结果的合理性。因此以卫星数据源为基础,分析了OPI方法处理下垫面参数导致的偏差,结合其导致的地表辐射收支差异说明不同空间尺度偏差的辐射收支效应,进而通过与CO2排放关联定量分析OPI方法对城市化气候效应的影响。结果发现随着空间尺度的变大,OPI方法导致的城市面积提取误差也在变大,导致城市下垫面转变成了其周边的土地覆盖类型,增强了城市群区域的反照率,降低了城市区域的辐射收支,弱化了城市气候效应。研究发现城市地表单位面积反照率增加0.01相当于减少了2.82kg的CO2排放,京津冀城市群2009年案例分析表明其弱化程度相当于减少了CO2排放2.28×105 t,扩展到中国区域尺度上则相当于减少了1.81×106 t CO2排放。
文摘An advanced three-level global atmospheric general circulation model has been used to study the summer precipitation anomaly in Northwest China.based on the synoptic fact and the statistical analysis of the precipitation,the surface albedo in Northwest China,and the synoptic systems over the Tibetan(Qinghai-Xizang)Plateau.The results show that either the anticyclone intensified over the plateau or the surface alhedo enhanced in Northwest China results in summer precipitation reduction east of Northwest China.Especially.when both of them appear simultaneously,summer precipitation was obviously reduced and severe drought occurred in most areas of Northwest China.Moreover.the simulated difference of precipitation rate of Northwest China is similar to the actural precipitation distribution in Northwest China in 1995,which is the most severe drought year in Northwest China in the past fifty years.So the tendency in drought severity intensified,drought frequency accelerated,drought persistence period extended,and drought areas expanded in Northwest China in recent years is maybe a result of the influences of human activities(e.g.vegetation was reduced,and desertification worsened)on drought circulation pattens over the Tibetan Plateau.
