Broad-scale predictability of carbohydrates and exopolymers in Antarctic and Arctic sea ice.
Broad-scale predictability of carbohydrates and exopolymers in Antarctic and Arctic sea ice.
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南极和北极海冰中碳水化合物和外聚物的大范围可预测性。
DOI：
10.1073/pnas.1302870110
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发表时间：
2013
影响因子：
11.1
通讯作者：
Underwood GJ
中科院分区：
文献类型：
--
作者：
Underwood GJ
海冰可以含有高浓度的溶解有机碳（DOC），其中大部分是由栖息在冰中的微藻和细菌产生的富含碳水化合物的胞外聚合物（EPS）。在这里，我们报告的浓度溶解碳水化合物（dCHO）和溶解EPS（dEPS）的关系，藻类现存量[估计叶绿素（Chl）浓度]在海冰从六个地点在南大洋和北冰洋。采样点内部和采样点之间的浓度差异很大，反映了当地的冰况和生物含量。然而，结合所有的数据显示强大的dCHO浓度和不同的dEPS组分，叶绿素a和DOC的浓度之间的统计关系。这些关系对于整个冰芯、底冰（生物量丰富）部分和较冷的表面冰都是正确的。dEPS的分布与藻类生物量密切相关，dEPS和非EPS碳水化合物的最高浓度都在冰的底层。复杂的EPS在较冷的表面海冰视野中更为普遍。预测模型（对独立的数据进行验证），使估计dCHO浓度的冰厚度，盐度和垂直位置的核心数据。当包括叶绿素时，获得了更高水平的预测。在这些关系中反映的一致模式提供了一个强有力的基础，包括估计区域和季节性的碳水化合物和dEPS碳预算耦合物理-地球化学模型，在不同类型的海冰从两个极地地区。
Sea ice can contain high concentrations of dissolved organic carbon (DOC), much of which is carbohydrate-rich extracellular polymeric substances (EPS) produced by microalgae and bacteria inhabiting the ice. Here we report the concentrations of dissolved carbohydrates (dCHO) and dissolved EPS (dEPS) in relation to algal standing stock [estimated by chlorophyll (Chl)aconcentrations] in sea ice from six locations in the Southern and Arctic Oceans. Concentrations varied substantially within and between sampling sites, reflecting local ice conditions and biological content. However, combining all data revealed robust statistical relationships between dCHO concentrations and the concentrations of different dEPS fractions, Chla, and DOC. These relationships were true for whole ice cores, bottom ice (biomass rich) sections, and colder surface ice. The distribution of dEPS was strongly correlated to algal biomass, with the highest concentrations of both dEPS and non-EPS carbohydrates in the bottom horizons of the ice. Complex EPS was more prevalent in colder surface sea ice horizons. Predictive models (validated against independent data) were derived to enable the estimation of dCHO concentrations from data on ice thickness, salinity, and vertical position in core. When Chladata were included a higher level of prediction was obtained. The consistent patterns reflected in these relationships provide a strong basis for including estimates of regional and seasonal carbohydrate and dEPS carbon budgets in coupled physical-biogeochemical models, across different types of sea ice from both polar regions.