Changes of the Arctic marginal ice zone during the satellite era
Changes of the Arctic marginal ice zone during the satellite era
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DOI：
10.5194/tc-14-1971-2020
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发表时间：
2020-06
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影响因子：
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通讯作者：
Rebecca J. Rolph;D. Feltham;D. Schröder
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文献类型：
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作者：
Rebecca J. Rolph;D. Feltham;D. Schröder
抽象。许多研究表明，北极海冰范围减少。然而，从逻辑上讲，边缘冰区（MIZ）的范围也在变化，这里定义为冰浓度从15%到80%的海洋区域。MIZ范围的变化对部分冰层覆盖的海洋地区的大气和海洋热量和气体交换水平以及依赖MIZ的生物体的栖息地范围产生影响，从海冰藻类到海豹和鸟类等初级生产者。在这里，我们提出，第一次，分析卫星观测的泛北极平均MIZ范围。我们没有发现任何趋势，在MIZ范围在过去40年的观察。我们的研究结果表明，恒定的MIZ范围是一个观察到的MIZ的宽度增加的结果被补偿的MIZ的周长减少，因为它进一步向北移动。我们提出了模拟从一个耦合的海冰-海洋混合层模型使用的预测浮冰的大小分布，我们发现是一致的，但约束不足，现有的卫星观测泛北极MIZ范围。我们提供了季节性的上限和下限MIZ范围的基础上使用的四个卫星获得的海冰浓度数据集。我们发现Bootstrap和OSI-450观测数据集的8月和9月MIZ分数（MIZ范围除以海冰范围）大幅增加（> 50%），这可以归因于总海冰范围的减少。鉴于这项研究的结果，我们建议，在MIZ的“快速变化”的提法应保持谨慎，并提供一个具体和明确的定义MIZ本身，也是MIZ的属性正在发生变化。
Abstract. Many studies have shown a decrease in Arctic sea ice extent. It does not logically follow, however, that the extent of the marginal ice zone (MIZ), here defined as the area of the ocean with ice concentrations from 15 % to 80 %, is also changing. Changes in the MIZ extent has implications for the level of atmospheric and ocean heat and gas exchange in the area of partially ice-covered ocean and for the extent of habitat for organisms that rely on the MIZ, from primary producers like sea ice algae to seals and birds. Here, we present, for the first time, an analysis of satellite observations of pan-Arctic averaged MIZ extent. We find no trend in the MIZ extent over the last 40 years from observations. Our results indicate that the constancy of the MIZ extent is the result of an observed increase in width of the MIZ being compensated for by a decrease in the perimeter of the MIZ as it moves further north. We present simulations from a coupled sea ice–ocean mixed layer model using a prognostic floe size distribution, which we find is consistent with, but poorly constrained by, existing satellite observations of pan-Arctic MIZ extent. We provide seasonal upper and lower bounds on MIZ extent based on the four satellite-derived sea ice concentration datasets used. We find a large and significant increase (>50 %) in the August and September MIZ fraction (MIZ extent divided by sea ice extent) for the Bootstrap and OSI-450 observational datasets, which can be attributed to the reduction in total sea ice extent. Given the results of this study, we suggest that references to “rapid changes” in the MIZ should remain cautious and provide a specific and clear definition of both the MIZ itself and also the property of the MIZ that is changing.