Clouds and Radiation Processes in Regional Climate Models Evaluated Using Observations Over the Ice‐free Arctic Ocean
Clouds and Radiation Processes in Regional Climate Models Evaluated Using Observations Over the Ice‐free Arctic Ocean
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利用无冰北冰洋观测评估区域气候模型中的云和辐射过程
DOI：
10.1029/2020jd033904
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Webster Stuart
中科院分区：
文献类型：
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作者：
Inoue Jun;Sato Kazutoshi;Rinke Annette;Cassano John J.;Fettweis Xavier;Heinemann Gunther;Matthes Heidrun;Orr Andrew;Phillips Tony;Seefeldt Mark;Solomon Amy;Webster Stuart
北极云层的存在调节了海冰表面和无冰海洋的表面能量收支（SEB）。在之前的几次野外活动之后，云与辐射的关系，包括云的垂直结构和相位，已经得到了阐明；然而，这种关系的建模已经慢慢成熟。由于认识到最近北极海冰范围的下降，在数值模式中云系统的表示应该考虑海冰覆盖区域和无冰区的影响。利用日本未来号科考船（2014年9月）在无冰北冰洋上获得的原位静止气象观测数据集，以云和SEB为重点，对6个区域气候模式（RCMs）进行了9次模式运行的协调评估。最显著的发现如下：(1)与观测结果相比，所有模式中低层云水的不稳定分层减少了；(2)单矩云方案和双矩云方案之间的云水表示存在显著差异；(3)包括固体/液体降水在内的水成物分配存在广泛差异；(4)对流层低层空气温度偏差明显。这些问题被认为是北冰洋无冰区SEB不确定性的主要来源。耦合RCM的结果表明，SEB受到大气和海洋（和海冰）的约束，并具有相当大的反馈。对独立大气和耦合rcm的协调改进将促进对北极气-冰-海耦合系统的更全面和更好的理解。
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 VesselMirai(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.