Climatology of Total Cloudiness in the Arctic: An Intercomparison of Observations and Reanalyses
Climatology of Total Cloudiness in the Arctic: An Intercomparison of Observations and Reanalyses
复制标题
北极总云量的气候学：观测与再分析的比较
DOI：
10.1155/2012/542093
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发表时间：
2012
影响因子：
2.9
通讯作者：
I. Mokhov
中科院分区：
文献类型：
--
作者：
A. Chernokulsky;I. Mokhov
北极（北纬 60°以北）上空的总云分数已根据来自不同卫星和表面观测和再分析的 16 个北极云气候进行了评估和相互比较。根据不同观测资料，北极年平均总云量约为0.70±0.03。海洋上较大（0.74±0.04），陆地上较小（0.67±0.03）。总云量的不同观测结果在夏季比在冬季、在海洋上比在陆地上更一致。根据所有观测，冬季的年际变化高于夏季。根据大多数观测结果，北极总云量具有显着的年周期。其最大时间与海冰范围最小时间（初夏至深秋）一致，反之亦然（晚春）。观测结果差异的主要原因是云探测算法的差异，特别是在冰雪表面（全年）或存在强烈低对流层逆温的区域（主要是冬季）探测到云时。一般来说，重新分析与北极云量的卫星和地面观测结果并不十分一致。
Total cloud fraction over the Arctic (north of 60°N) has been evaluated and intercompared based on 16 Arctic cloud climatologies from different satellite and surface observations and reanalyses. The Arctic annual-mean total cloud fraction is about 0.70±0.03 according to different observational data. It is greater over the ocean (0.74±0.04) and less over land (0.67±0.03). Different observations for total cloud fraction are in a better agreement in summer than in winter and over the ocean than over land. An interannual variability is higher in winter than in summer according to all observations. The Arctic total cloud fraction has a prominent annual cycle according to most of the observations. The time of its maximum concurs with the time of the sea ice extent minimum (early summer–late autumn) and vice versa (late spring). The main reason for the discrepancies among observations is the difference in the cloud-detection algorithms, especially when clouds are detected over the ice/snow surface (during the whole year) or over the regions with the presence of strong low-tropospheric temperature inversions (mostly in winter). Generally, reanalyses are not in a close agreement with satellite and surface observations of cloudiness in the Arctic.