Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ice.
Leads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ice.
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北极浮冰中的铅使得浮游植物在冰雪覆盖的海冰下提前繁殖。
DOI：
10.1038/srep40850
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发表时间：
2017-01-19
影响因子：
4.6
通讯作者：
Granskog MA
中科院分区：
文献类型：
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作者：
Assmy P;Fernández-Méndez M;Duarte P;Meyer A;Randelhoff A;Mundy CJ;Olsen LM;Kauko HM;Bailey A;Chierici M;Cohen L;Doulgeris AP;Ehn JK;Fransson A;Gerland S;Hop H;Hudson SR;Hughes N;Itkin P;Johnsen G;King JA;Koch BP;Koenig Z;Kwasniewski S;Laney SR;Nicolaus M;Pavlov AK;Polashenski CM;Provost C;Rösel A;Sandbu M;Spreen G;Smedsrud LH;Sundfjord A;Taskjelle T;Tatarek A;Wiktor J;Wagner PM;Wold A;Steen H;Granskog MA
北极冰盖正在迅速从较厚的多年冰盖转变为较薄的主要是季节性的第一年冰盖，对北极初级生产产生重大影响。一个关键的挑战是了解生产力在未来几十年内将如何变化。最近的研究报告称，夏季期间在积水海冰下出现了大面积浮游植物水华，这表明基于卫星的北极年度初级生产量估计数可能被大大低估。在这里，我们提出了一个独特的时间序列的浮游植物春季水华下观察积雪覆盖的北极浮冰。浮游藻类普氏棕囊藻（Phaeocystis pouchetii）占主导地位的水华导致表层硝酸盐存量几乎耗尽，溶解无机碳减少了16 ± 6 g C m−2。该地区的海洋环流特征表明，尽管有冰雪覆盖的海冰，水华仍在原地发展。动态冰盖中的铅提供了启动和维持水华所需的额外阳光。尽管预计北极高降雪量会增加，但由于海冰变薄和更具活力，未来北冰洋的浮游植物在冰雪覆盖的冰层下大量繁殖可能会变得更加普遍和广泛，并经常形成铅。这可能会改变北冰洋的生产力、海洋食物网和碳固存。
The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice. The bloom, dominated by the haptophyte algae Phaeocystis pouchetii, caused near depletion of the surface nitrate inventory and a decline in dissolved inorganic carbon by 16 ± 6 g C m−2. Ocean circulation characteristics in the area indicated that the bloom developed in situ despite the snow-covered sea ice. Leads in the dynamic ice cover provided added sunlight necessary to initiate and sustain the bloom. Phytoplankton blooms beneath snow-covered ice might become more common and widespread in the future Arctic Ocean with frequent lead formation due to thinner and more dynamic sea ice despite projected increases in high-Arctic snowfall. This could alter productivity, marine food webs and carbon sequestration in the Arctic Ocean.