【作者】 马越界；

【导师】 黄建平；

【作者基本信息】 兰州大学 ， 大气物理学与大气环境， 2011， 硕士

【摘要】 云-辐射相互作用是气候变化研究中重要的不确定因素之一。获取不同垂直结构云的信息及其对辐射收支的影响,对于全球气候变化的研究至关重要。云卫星(Cloudsat)是世界上第一颗用于研究云的卫星,首次从太空中对全球云层的垂直结构和微物理特性进行了观测,因此,Cloudsat观测资料的分析和应用,将有助于进一步理解云-气候反馈作用,减小气候变化研究中的不确定性。本文利用Cloudsat提供的云类、云辐射强迫资料,以及CERES_SSF云量,分析了青藏高原夏季总云量的时空变化特征及云辐射强迫。研究结果表明：随着季风的到来,夏季青藏高原的总云量逐渐增加,并在8月份总达到最大；总云量总体呈现南高北低的空间分布特征,与地形分布配合较好；在云量的高值区,大气顶(TOA)和大气底(BOA)的云短波辐射强迫也较大。利用Cloudsat搭载的毫米波雷达提供的大气加热率资料,论文对比分析了青藏高原出现单层云、多层云以及多种类型云同时存在对大气加热率的影响。研究结果发现：1)存在单层云时,在云层内短波加热效应显著,而在云顶,长波冷却效应较为显著；2)存在多层云时,云顶和云内的大气加热率与单层云类似,而在云层之间,长波的冷却效应显著,云对大气的影响表现为冷却效应,其最高值接近于云顶对大气的冷却率；3)对于多种类型云同时存在的情况,大气加热率在数值上可以看作是不同单层云在垂直方向上的叠加。更多还原

【Abstract】 Cloud-radiation interaction is an important factor of uncertainty in climate change research. Obtaining information of clouds with different heights and its impact on the radiation budget, is necessary to the study of global climate change. Cloudsat is the first satellite for the study of cloud. We can see the vertical structure of the global clouds and get microphysical characteristics of clouds by using it. Through this process, we can better understanding the cloud-climate feedback in climate change research and thus reduce uncertainty.In this paper, we analysed the total cloud amount and cloud radiative forcing, by using cloud type and cloud radiative forcing data provided by Cloudsat and cloud amount data from CERES_SSF. The conclusions suggest that, the clouds amount over Tibetan Plateau gradually increased carried on monsoon winds, and in August, the clouds amount reaches maximum. Due to the effect of landforms of Plateau, the clouds amount over Southern Plateau is much great then Northern. In the high cloud amount area, the absolute value of Short Wave cloud radiative forcing at TOA and BOA are also higher and low amount area.We also used atmosphere heating data from Cloudsat, and selected out three example of cloud over Tibetan Plateau, corresponding to single clouds, multi-layer clouds and various types of clouds. The results showed that:clouds heat the atmosphere via absorption of SW radiation inside the cloud. The single clouds cool the atmosphere by emission LW radiation near the top of cloud layers and heat the atmosphere due to the ’green house’ effect. Multi-layer clouds have an obviously cooling effect on net heating rate and the maximum is close to cooling rate near the top of cloud. The heating rate of different kinds of cloud can be treated as the sum of these kinds of single-layer clouds in vertical distribution.更多还原