RAPID: Evaluation of CAM4 and CCSM4 Boundary Layer Clouds, Radiation, and Precipitation over the VOCALS Region

海洋大气边界层云在大气和大气-海洋耦合模式中的重要性已得到广泛认识，特别是在2008年10月和11月进行了VOCALS （VAMOS Ocean Cloud - Atmosphere - Land Study）野外试验的东南太平洋地区。美国国家大气研究中心（NCAR）将于2009年夏天发布新版社区气候系统模式（CCSM4）。该模型将用于即将到来的IPCC（政府间气候变化专门委员会）第五次评估（AR5）。CCSM4将包括对云、辐射、降水和其他过程的模式公式进行重大修订，与早期版本相比，这些过程可能会改善整体气候模拟，但不确定它是否会继续存在该模式当前版本以及其他主要全球气候模式中发现的一些相同问题（在过程层面）。使用CCSM4的模拟将构成美国对IPCC AR5的主要贡献。这个RAPID项目将为CCSM4建模小组提供及时和详细的信息，了解CCSM4在长期存在问题的VOCALS区域的表现。来自VOCALS和早期实验的现场数据以及卫星测量将用于评估CCSM4的边界层云、短波和长波辐射以及降水，重点是在单个时间步长进行的预算分析。CCSM4代表了美国对IPCC AR5的主要贡献，对科学、社会和政策具有重要意义。这个项目将包括培养一名研究生。研究结果将通过网页及时提供给研究界。

The importance of marine atmospheric boundary layer clouds in atmospheric and atmosphere-ocean coupled models has been widely recognized, particularly over the Southeast Pacific where the VOCALS (VAMOS Ocean Cloud Atmosphere Land Study) field experiment was carried out in October and November of 2008. NCAR (the National Center for Atmospheric Research) will release the new version of the Community Climate System Model (CCSM4) in the summer of 2009. This model will be used for the upcoming Fifth Assessment (AR5) of the IPCC (Intergovernmental Panel on Climate Change). CCSM4 will include significantly revised model formulations for clouds, radiation, precipitation, and other processes that may improve the overall climate simulation compared with earlier versions, but it is uncertain whether it may continue to have some of the same problems (at the process level) as identified in the current version of this model, as well in as other leading global climate models. Simulations using CCSM4 will comprise a major U.S. contribution to the IPCC AR5. This RAPID project will provide CCSM4 modeling groups with timely and detailed information on how CCSM4 performs in the perennially problematic VOCALS region.In situ data from VOCALS and earlier experiments, as well as satellite measurements, will be used to evaluate the boundary layer clouds, shortwave and longwave radiation, and precipitation in CCSM4, focusing on budget analyses carried out at individual time steps.CCSM4 represents a major U.S. contribution to the IPCC AR5, with significant implications for science, society, and policy. This project will involve the training of a graduate student. Results will be made available, in a timely manner, to the research community through a web page.