The presence of clouds in the Arctic regulates the surface energy budget (SEB) over the sea‐ice surface and the ice‐free ocean. Following several previous field campaigns, the cloud‐radiation relationship, including cloud vertical structure and phase, has been elucidated; however, modeling of this relationship has matured slowly. In recognition of the recent decline in the Arctic sea‐ice extent, representation of the cloud system in numerical models should consider the effects of areas covered by sea ice and ice‐free areas. Using an in situ stationary meteorological observation data set obtained over the ice‐free Arctic Ocean by the Japanese Research Vessel Mirai (September 2014), coordinated evaluation of six regional climate models (RCMs) with nine model runs was performed by focusing on clouds and the SEB. The most remarkable findings were as follows: (1) reduced occurrence of unstable stratification with low‐level cloud water in all models in comparison to the observations, (2) significant differences in cloud water representations between single‐ and double‐moment cloud schemes, (3) extensive differences in partitioning of hydrometeors including solid/liquid precipitation, and (4) pronounced lower‐tropospheric air temperature biases. These issues are considered as the main sources of SEB uncertainty over ice‐free areas of the Arctic Ocean. The results from a coupled RCM imply that the SEB is constrained by both the atmosphere and the ocean (and sea ice) with considerable feedback. Coordinated improvement of both stand‐alone atmospheric and coupled RCMs would promote a more comprehensive and improved understanding of the Arctic air‐ice‐sea coupled system.

中文翻译：

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使用无冰北冰洋的观测评估区域气候模型中的云和辐射过程

北极地区云层的存在调节着海冰表面和无冰海洋的表面能收支（SEB）。在先前的几次野战之后，已经阐明了云辐射关系，包括云垂直结构和相位。但是，这种关系的模型已经慢慢成熟。考虑到北极海冰范围最近的下降，在数值模型中云系统的表示应考虑海冰和无冰区所覆盖区域的影响。利用日本研究船Mirai在无冰的北冰洋获得的原地静止气象观测数据集（2014年9月），通过关注云和SEB，对六个区域气候模型（RCM）和九个模型运行进行了协调评估。最显着的发现如下：（1）与观测值相比，在所有模型中使用低水平云水减少了不稳定分层的发生；（2）单矩云方案和双矩云方案之间云水表示的显着差异； （3）包括固体/液体沉淀在内的水凝物分配的广泛差异，以及（4）对流层大气温度偏低明显。这些问题被认为是北冰洋无冰地区SEB不确定性的主要来源。耦合RCM的结果表明SEB受大气和海洋（和海冰）的约束，并具有可观的反馈。