Predictability of the Arctic sea ice edge
Predictability of the Arctic sea ice edge
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DOI：
10.1002/2015gl067232
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发表时间：
2016-02-28
影响因子：
5.2
通讯作者：
Jung, T.
中科院分区：
文献类型：
--
作者：
Goessling, H. F.;Tietsche, S.;Jung, T.
对北极地区人类活动的操作和规划来说，熟练的海冰预报在数天到数年内变得越来越重要。本文分析了六种气候模式对北极海冰边缘的潜在可预测性。我们引入了综合冰边误差（IIEE），这是一个与用户相关的验证度量，定义为预测和“事实”在冰浓度高于或低于15%时不一致的区域。IIEE可以分解为一个绝对范围误差，对应于常见的海冰范围误差和一个错位误差。我们发现，经常被忽视的错位误差占气候IIEE的一半以上。在7月1日初始化的理想预报集合中，IIEE的增长速度快于绝对程度误差。这意味着北极海冰边缘比海冰范围更难以预测，特别是在9月份，这对最终用户相关预测的潜在技能产生了影响。
Skillful sea ice forecasts from days to years ahead are becoming increasingly important for the operation and planning of human activities in the Arctic. Here we analyze the potential predictability of the Arctic sea ice edge in six climate models. We introduce the integrated ice-edge error (IIEE), a user-relevant verification metric defined as the area where the forecast and the "truth" disagree on the ice concentration being above or below 15%. The IIEE lends itself to decomposition into an absolute extent error, corresponding to the common sea ice extent error, and a misplacement error. We find that the often-neglected misplacement error makes up more than half of the climatological IIEE. In idealized forecast ensembles initialized on 1 July, the IIEE grows faster than the absolute extent error. This means that the Arctic sea ice edge is less predictable than sea ice extent, particularly in September, with implications for the potential skill of end-user relevant forecasts.