【作者】 邹松佐；

【导师】 郭品文；

【作者基本信息】 南京信息工程大学 ， 气候资源开发与利用， 2012， 硕士

【摘要】 本文利用NCAR最新大气环流模式CAM5.1设计了一系列数值试验,对我国东部大规模城市化可能对东亚地区冬夏季环流及降水分布所产生的影响进行了讨论,其中,对大规模城市化的表现分为两个方面来讨论——城市比重的增加及黑碳气溶胶排放量的增多。主要结论如下：(1) CAM5.1模式对全球及东亚地区的冬、夏季环流场及降水等物理量场均具有较强的模拟能力,控制试验结果很好地反映出观各个气象要素的实际状况。(2)中国东部大规模城市比重增加后,夏季东亚低层气温升高,海平面气压差值呈现“南负北正”的分布,30°N~40°N对流层下层的大气由于受热而产生上升运动,在该上升气流的影响下,我国东部及其附近的沿海地区出现一个气旋性差值环流,差值环流中心位于江淮地区附近,40°N以南地区的降水呈现“东正西负”的差值分布型,这样的差值环流场、降水场与观测事实非常相似。(3)中国东部大规模城市下垫面比重增加后,东亚地区冬季低层气温显著升高,40°N以南的升温可达到200hPa左右,同时海平面气压降低,台湾以东洋面上存在一差值反气旋,该反气旋与我国大陆上的差值气旋之间的偏南气流影响我国东部,从而对东亚冬季风起到了削弱作用,40°N以南的大部分地区降水增多,降水增大中心位于长三角附近。这与观测事实也非常相似。(4)中国东部地区黑碳气溶胶含量加倍时,东亚地区夏季中低层温度升高,而黑碳气溶胶含量较多的长三角至山东半岛附近的两米气温稍有降低,这与黑碳气溶胶对短波辐射的遮挡效应有关。东亚地区夏季海平面气压由南向北呈现“+,-,+”的差值分布,南海及其以东地区850hPa存在一差值反气旋,其西北部的偏南气流影响我国东部地区,使得我国东部的降水由南至北呈现“-,+,-”的差值分布。(5)中国东部城市群区的黑碳气溶胶含量加倍之后,长三角以北的两米气温降低,这是由黑碳气溶胶对太阳辐射的遮挡作用引起的。我国东部大陆上产生一个差值气旋,该差值气旋中心位于110°E附近,其东侧偏南气流影响我国东南沿海,导致冬季我国大部降水增多。这与城市下垫面比重增加时的冬季结果很类似,同时与观测事实较为符合。更多还原

【Abstract】 Using the latest Community Atmosphere Model Version5.1from NCAR, this article focuses on the impacts of large-scale urbanization around eastern China on the summer and winter circulation and rainfall distribution around eastern Asia. Two aspects of urbanization are discussed in this paper-the change of underlying ground surface and the discharging volume of black carbon aerosol.The main results are as follows:(1) The simulation results of global and eastern Asian atmosphere circulation in summer and winter using CAM5.1are very similar to the observation results.(2) When the percentage of urban underlying surface rises, the nearby low level air temperature of summer goes up, and the abnormal sea level pressure(slp) around eastern Asia represents positive and negative pattern from the north to the south. An abnormal cyclone appears around the eastern coast of China, which centers around Jianghuai region. The rainfall distribution appears to be positive and negative pattern from the eastern to western China. The characteristics of simulation results are very similar to the observational facts.(3) When the percentage of urban underlying surface rises, the nearby winter temperature rises significantly even up to200hPa, meanwhile, the slp drops and an abnormal anticyclone appears to the east of Taiwan, the southerly wind between the two abnormal systems lead to more rainfall in most of China.(4) When the volume of black carbon aerosol around eastern China doubles, the air temperature rises from the low level to the middle level in summer, together with a slight reduction of surface air temperature near Shandong. An abnormal anticyclone appears around South China Sea, the southerly wind to the north of the anticyclone affects the eastern part of China, and the abnormal rainfall distribution represents negative, positive and negative pattern from the south to the north of eastern China.(5) When the volume of black carbon aerosol around eastern China doubles, a reduction of surface air temperature appears nearby. There forms an abnormal cyclone, which centers around110°E, thus the eastern China is controlled by southerly wind and most region of China gets more precipitation in winter.更多还原