Annual Cycles of Sea Ice Motion and Deformation Derived From Buoy Measurements in the Western Arctic Ocean Over Two Ice Seasons
Annual Cycles of Sea Ice Motion and Deformation Derived From Buoy Measurements in the Western Arctic Ocean Over Two Ice Seasons
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DOI：
10.1029/2019jc015310
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发表时间：
2020-06
期刊：
影响因子：
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通讯作者：
R. Lei;Dawei Gui;J. Hutchings;P. Heil;Na Li
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文献类型：
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作者：
R. Lei;Dawei Gui;J. Hutchings;P. Heil;Na Li
在2014/2015和2016/2017冰季期间运作的两个浮标阵列收集的数据被用来描述北冰洋西部冰运动和变形的年度周期。2014/2015和2016/2017年异常强和弱的Beaufort Gyre分别在2014/2015和2016/2017年期间引发了普遍的反气旋和气旋性海冰漂移。与2014/2015年相比，2016/2017年的气旋性冰运动导致冰散度对总冰形变的贡献更大。2014年秋季海冰集中度和多年冰盖均高于2016年，因此，海冰运动对风的响应较弱，2014年秋季观测到的海冰变形较少。在秋冬季转换期间，由于浮冰的冻结和固结，2014/2015和2016/2017两年的冰风比、冰形变速率及其时空标度指数和冰形变局部化都明显减少。随着冰盖的进一步增厚，这种动态行为一直保持到春季。随着夏季的临近，由于冰的强度减弱，冰的变形增加。2014/2015年，特别是2016/2017年，北冰洋西部海冰形变速率的年周期幅度大于1997/1998年北冰洋表面热收支(SHEBA)计划期间的观测结果。我们将这一现象归因于最近几个夏季的冰层融化，尤其是多年厚的冰层。
Data collected by two buoy arrays that operated during the ice seasons of 2014/2015 and 2016/2017 were used to characterize annual cycles of ice motion and deformation in the western Arctic Ocean. An anomalously strong and weak Beaufort Gyre in 2014/2015 and 2016/2017 induced generally anticyclonic and cyclonic sea ice drift during 2014/2015 and 2016/2017, respectively. Cyclonic ice motion resulted in higher contributions of ice divergence to total ice deformation in 2016/2017 than in 2014/2015. In 2014, the autumn ice concentration and multiyear ice coverage were higher than in 2016; consequently, the response of ice motion to wind forcing was weak, and less ice deformation was observed in autumn 2014. During the autumn‐winter transition, the ice‐wind speed ratio, ice deformation rate and its spatial and temporal scaling exponents, and localization of ice deformation decreased markedly in both 2014/2015 and 2016/2017 as a result of freeze‐up and consolidation of ice floes. Such dynamic behavior was maintained through to spring with the further thickening of ice cover. Ice deformation increased due to weakened ice strength as summer approached. The amplitude of the annual cycle of ice deformation rate in the western Arctic Ocean in 2014/2015 and especially in 2016/2017 was larger than that observed during the Surface Heat Budget of the Arctic Ocean (SHEBA) program in 1997/1998. We attribute this phenomenon to ice loss during the recent summers, especially of thick multiyear ice.