Glacial meltwater dynamics in coastal waters west of the Antarctic peninsula
Glacial meltwater dynamics in coastal waters west of the Antarctic peninsula
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DOI：
10.1073/pnas.032206999
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发表时间：
2002-02-19
影响因子：
11.1
通讯作者：
Vernet, M
中科院分区：
文献类型：
--
作者：
Dierssen, HM;Smith, RC;Vernet, M
海冰每年的进退被认为是南极沿海海洋生态系统时空变化的主要物理决定因素。然而，冰川融水对南极半岛生态系统水文学的作用在很大程度上被忽视了，由此产生的生物效应也只被考虑到距海岸几公里范围内。通过与帕尔默站长期生态研究项目一起收集的几条证据，我们表明，夏季沿海地表水的清新和变暖不仅如文献所暗示的那样受到海冰融化的影响，而且很大程度上受到冰川融水流入的影响。此外，冰川融水羽流数量和范围的季节性变化通过影响水的物理动力学（例如水柱分层、近岸浊度），在生物群的功能中发挥着关键作用。根据近十年的观察（19911999），表面融水的存在不仅与近岸浮游植物的大量繁殖有关，而且在空间上与近海 100 公里以上的浮游植物繁殖有关。融水量还会影响海冰形成的时间，从而对生态系统产生重要的二次影响。由于南极半岛地区的气温在统计上呈上升趋势，冰川融水的存在可能会在这些地表水域中变得更加普遍，并在推动这一脆弱的生态系统方面继续发挥越来越大的作用。
The annual advance and retreat of sea ice has been considered a major physical determinant of spatial and temporal changes in the structure of the Antarctic coastal marine ecosystem. However, the role of glacial meltwater on the hydrography of the Antarctic Peninsula ecosystem has been largely ignored, and the resulting biological effects have only been considered within a few kilometers from shore. Through several lines of evidence collected in conjunction with the Palmer Station Long-Term Ecological Research Project, we show that the freshening and warming of the coastal surface water over the summer months is influenced not solely by sea ice melt, as suggested by the literature, but largely by the influx of glacial meltwater. Moreover, the seasonal variability in the amount and extent of the glacial meltwater plume plays a critical role in the functioning of the biota by influencing the physical dynamics of the water (e.g., water column stratification, nearshore turbidity). From nearly a decade of observations (19911999), the presence of surface meltwater is correlated not only to phytoplankton blooms nearshore, but spatially over 100 km offshore. The amount of meltwater will also have important secondary effects on the ecosystem by influencing the timing of sea ice formation. Because air temperatures are statistically increasing along the Antarctic Peninsula region, the presence of glacial meltwater is likely to become more prevalent in these surface waters and continue to play an ever-increasing role in driving this fragile ecosystem.