Large-Scale Variability of Physical and Biological Sea-Ice Properties in Polar Oceans
Large-Scale Variability of Physical and Biological Sea-Ice Properties in Polar Oceans
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DOI：
10.3389/fmars.2020.00536
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发表时间：
2020-08-12
影响因子：
3.7
通讯作者：
Flores, Hauke
中科院分区：
文献类型：
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作者：
Castellani, Giulia;Schaafsma, Fokje L.;Flores, Hauke
在这项研究中，我们介绍了2012至2017年间五次活动期间使用水面和冰下拖网(套装)收集的独特数据，涵盖了北冰洋从春季到夏季和秋季的过渡，以及南大洋冬季和夏季的季节。这套衣服配备了一个传感器阵列，我们从中提取了：海冰厚度、海冰底部的光场、冰中的叶绿素a浓度(冰内chla)以及冰下水的盐度、温度和chla浓度。两极地区的平均拖网距离约为2公里，全球样带长度超过117公里，这是首次基于千米尺度剖面的多季节栖息地特征。目前的数据突出了极地海洋海冰性质的区域和季节模式。在夏季，北极海冰的透光率几乎达到100%，当时冰层较薄，融化的池塘覆盖在冰面上。而海冰下的日积光量在春季最大。与北极相比，南极海冰较薄，积雪深度较厚，海冰特性在不同季节之间更加均匀。冬季透光率较低，最大透过率为73%。尽管积雪较厚，但南极夏季的总体冰下光照比北极夏季要高得多。空间自相关分析表明，与南极相比，北极海冰具有较大的浮冰特征。在两个极地地区，透过率的斑块大小随海冰厚度的空间变化而变化。北冰洋冰内Chla保持在0.39 mg Chl am(-2)以下，而南极冬季超过7 mg Chl Am(-2)，此时水体Chl a浓度保持在1.5 mg Chl Am(-2)以下，从而突出了其作为越冬生物重要碳源的潜力。本研究中分析的数据可以改进在气候变化影响和海洋管理背景下分析的大规模物理和生态系统模型、栖息地地图研究和时间序列。
In this study, we present unique data collected with a Surface and Under-Ice Trawl (SUIT) during five campaigns between 2012 and 2017, covering the spring to summer and autumn transition in the Arctic Ocean, and the seasons of winter and summer in the Southern Ocean. The SUIT was equipped with a sensor array from which we retrieved: sea-ice thickness, the light field at the underside of sea ice, chlorophyll a concentration in the ice (in-ice chl a), and the salinity, temperature, and chl a concentration of the under-ice water. With an average trawl distance of about 2 km, and a global transect length of more than 117 km in both polar regions, the present work represents the first multi-seasonal habitat characterization based on kilometer-scale profiles. The present data highlight regional and seasonal patterns in sea-ice properties in the Polar Ocean. Light transmittance through Arctic sea ice reached almost 100% in summer, when the ice was thinner and melt ponds spread over the ice surface. However, the daily integrated amount of light under sea ice was maximum in spring. Compared to the Arctic, Antarctic sea-ice was thinner, snow depth was thicker, and sea-ice properties were more uniform between seasons. Light transmittance was low in winter with maximum transmittance of 73%. Despite thicker snow depth, the overall under-ice light was considerably higher during Antarctic summer than during Arctic summer. Spatial autocorrelation analysis shows that Arctic sea ice was characterized by larger floes compared to the Antarctic. In both Polar regions, the patch size of the transmittance followed the spatial variability of sea-ice thickness. In-ice chl a in the Arctic Ocean remained below 0.39mg chl am(-2), whereas it exceeded 7mg chl am(-2) during Antarctic winter, when water chl a concentrations remained below 1.5mg chl am(-2), thus highlighting its potential as an important carbon source for overwintering organisms. The data analyzed in this study can improve large-scale physical and ecosystem models, habitat mapping studies and time series analyzed in the context of climate change effects and marine management.