Mechanisms for and predictability of a drastic reduction in the Arctic sea ice: APPOSITE data with climate model MIROC
Mechanisms for and predictability of a drastic reduction in the Arctic sea ice: APPOSITE data with climate model MIROC
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北极海冰急剧减少的机制和可预测性：气候模型 MIROC 的相应数据
DOI：
10.1175/jcli-d-18-0195.1
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发表时间：
2019
影响因子：
4.9
通讯作者：
Y.
中科院分区：
文献类型：
--
作者：
Ono;J.;Tatebe;H.;and Komuro;Y.
北极海冰范围（SIE）急剧减少的机制和可预测性进行了研究，使用跨学科气候研究模式（MIROC）版本5.2。在这里，控制（CTRL）与强迫固定在2000年的水平和完美的模式集合预报（PRED）的实验进行。在CTRL中，在200年的整合过程中，发生了三次（型号年份51、56和57）SIE急剧减少。在第56年，海冰离岸移动与夏季北极偶极子异常（ADA）指数的正相和融化，由于通过增加开放水域面积的热量输入，和SIE急剧下降。这为57年北冰洋内部处于温暖状态，春季海冰量由于前一年冰量急剧减少而出现较大的负距平时，SIE最低提供了预条件。虽然ADA是海冰减少背后的关键机制之一，但它并不总是导致大幅减少。我们的分析表明，有利于近海冰运动的风向是一个更重要的因素，剧烈的冰减少事件。在经历剧烈冰减少事件的年份，9月SIE可以巧妙地预测从7月开始的PRED，但不能从4月开始。这是因为PRED从4月开始对7月海平面气压、冰缘沿着海冰密集度和海冰厚度的预报误差较大。
The mechanisms for and predictability of a drastic reduction in the Arctic sea ice extent (SIE) are investigated using the Model for Interdisciplinary Research on Climate (MIROC) version 5.2. Here, a control (CTRL) with forcing fixed at year 2000 levels and perfect-model ensemble prediction (PRED) experiments are conducted. In CTRL, three (model years 51, 56, and 57) drastic SIE reductions occur during a 200-yr-long integration. In year 56, the sea ice moves offshore in association with a positive phase of the summer Arctic dipole anomaly (ADA) index and melts due to heat input through the increased open water area, and the SIE drastically decreases. This provides the preconditioning for the lowest SIE in year 57 when the Arctic Ocean interior is in a warm state and the spring sea ice volume has a large negative anomaly due to drastic ice reduction in the previous year. Although the ADA is one of the key mechanisms behind sea ice reduction, it does not always cause a drastic reduction. Our analysis suggests that wind direction favoring offshore ice motion is a more important factor for drastic ice reduction events. In years experiencing drastic ice reduction events, the September SIE can be skillfully predicted in PRED started from July, but not from April. This is because the forecast errors for the July sea level pressure and those for the sea ice concentration and sea ice thickness along the ice edge are large in PRED started from April.