On the statistical properties of sea-ice lead fraction and heat fluxes in the Arctic
On the statistical properties of sea-ice lead fraction and heat fluxes in the Arctic
复制标题
北极海冰铅分数和热通量的统计特性
DOI：
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发表时间：
2021
期刊：
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通讯作者：
V. Dansereau
中科院分区：
文献类型：
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作者：
Einar Örn Ólason;P. Rampal;V. Dansereau
抽象的。我们探讨了几个统计特性的观测和模拟北极海冰铅分数，以及模拟北极海洋-大气热通量的统计。
首先，我们发现，在北极中部观察到的铅分数有一个单分形的空间尺度，我们涉及到海冰变形率中存在的多重分形空间尺度。
然后，我们表明，在北极中部观测到的铅含量的相关统计数据，以及我们的模型，neXtSIM。
考虑到通过引线的热通量可能比通过未破碎的冰的热通量大2个数量级，然后我们探索了neXtSIM模拟的热通量的统计特性（概率分布函数- PDF -和空间尺度）。
我们表明，模拟的热通量提出了一个多重分形尺度在北极中部，通过铅热通量占主导地位的PDF的高通量的尾巴。这种多重分形特征与变形率和铅含量的多重分形和单分形特征有关。在更广泛的北极地区，PDF的高通量尾部主要是由指数衰减，我们归因于沿海冰穴的存在。
最后，我们表明，模拟的铅分数和热通量的缩放依赖于弱模型的分辨率和讨论的作用，子网格尺度的冰的异质性参数化可能有改善这一结果。
Abstract. We explore several statistical properties of the observed and simulated Arctic sea-ice lead fraction, as well as the statistics of simulated Arctic ocean–atmosphere heat fluxes.
First we show that the observed lead fraction in the Central Arctic has a monofractal spatial scaling, which we relate to the multifractal spatial scaling present in sea-ice deformation rates.
We then show that the relevant statistics of the observed lead fraction in the Central Arctic are well represented by our model, neXtSIM.
Given that the heat flux through leads may be up to 2 orders of magnitude larger than that through unbroken ice, we then explore the statistical properties (probability distribution function – PDF – and spatial scaling) of the heat fluxes simulated by neXtSIM.
We demonstrate that the modelled heat fluxes present a multifractal scaling in the Central Arctic, where heat fluxes through leads dominate the high-flux tail of the PDF. This multifractal character relates to the multi- and monofractal character of deformation rates and the lead fraction. In the wider Arctic, the high-flux tail of the PDF is dominated by an exponential decay, which we attribute to the presence of coastal polynyas.
Finally, we show that the scaling of the simulated lead fraction and heat fluxes depends weakly on the model resolution and discuss the role sub-grid-scale parameterisations of the ice heterogeneity may have in improving this result.