On the freshening of the northwestern Weddell Sea continental shelf
On the freshening of the northwestern Weddell Sea continental shelf
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DOI：
10.5194/os-7-305-2011
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发表时间：
2011-01-01
期刊：
影响因子：
3.2
通讯作者：
Timmermann, R.
中科院分区：
文献类型：
--
作者：
Hellmer, H. H.;Huhn, O.;Timmermann, R.
我们分析了威德尔海西北部大陆架 1989 年、1997 年和 2006 年三个冬季以及上次冬季航行后两个夏季的水文数据。夏季，南纬 64 度附近存在一个热锋，将寒冷的南部水域与温暖的北部水域分开，这些水域具有与布兰斯菲尔德海峡中央盆地深水相似的特征。冬季，整个大陆架呈现出南方特征，氖（Ne）浓度较高，表明冰川融水大量输入。对南极半岛尖端浅层陆架17年的冬季数据进行比较显示，整个水柱的盐度下降了0.09，其停留时间<1年。我们将这种清新解释为由于海冰向南退缩导致盐输入减少和 20 世纪末威德尔海西部大陆架降水量增加共同造成的。然而，盐化减少也可能是由于以前被拉森 A 和 B 冰架占据的沿海地区海冰形成导致的盐输入增加与拉森 C 冰损失增加之间的微妙相互作用造成的。
We analyzed hydrographic data from the northwestern Weddell Sea continental shelf of the three austral winters 1989, 1997, and 2006 and two summers following the last winter cruise. During summer a thermal front exists at similar to 64 degrees S separating cold southern waters from warm northern waters that have similar characteristics as the deep waters of the central basin of the Bransfield Strait. In winter, the whole continental shelf exhibits southern characteristics with high Neon (Ne) concentrations, indicating a significant input of glacial melt water. The comparison of the winter data from the shallow shelf off the tip of the Antarctic Peninsula, spanning a period of 17 yr, shows a salinity decrease of 0.09 for the whole water column, which has a residence time of < 1 yr. We interpret this freshening as being caused by a combination of reduced salt input due to a southward sea ice retreat and higher precipitation during the late 20th century on the western Weddell Sea continental shelf. However, less salinification might also result from a delicate interplay between enhanced salt input due to sea ice formation in coastal areas formerly occupied by Larsen A and B ice shelves and increased Larsen C ice loss.