Sea ice transports in the Weddell Sea
Sea ice transports in the Weddell Sea
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威德尔海的海冰运输
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
V. Strass
中科院分区：
文献类型：
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作者：
Sabine Harms;E. Fahrbach;V. Strass
在威德尔海海冰草案的时间序列进行评估，水文观测，卫星被动微波数据，冰漂移的淡水通量估计和威德尔海。自1990年以来，沿沿着两条横跨威德尔环流的断面，用系泊的向上看的声纳测量冰吃水。一个样带，从南极半岛的尖端延伸到Kapp Norvegia，在1990年和1994年之间进行了采样，涵盖了流入和流出南部威德尔海。另一个样带是自1996年以来取样的，从南极大陆沿着格林威治子午线向北延伸，涵盖了威德尔海东部和西部之间的水团交换。为了将不同时间段的结果联系起来，建立了海冰季节长度与（1）年平均冰吃水和（2）年平均冰量输送之间的经验关系，海冰季节长度是由卫星被动微波数据得出的，定义为每年海冰浓度超过15%的天数。通过使用这些经验关系，得出了1979年2月至1999年2月期间所有系泊点的年平均冰吃水和冰量输送的估计值。风和海流迫使威德尔海东部沿海地区的冰向西输送，西部的冰向北输送。在1991/1992两年期间，威德尔海的平均冰输出量为（50 ± 19）× 103 m3 s-1。这一淡水输出代表了较长期（20年）的平均值，超过了降水和冰架融化所获得的平均淡水量约19×103 m3 s−1，从而得出威德尔海新通风底层水形成速率的上限为2.6 Sv。
Time series of sea ice draft in the Weddell Sea are evaluated together with hydrographic observations, satellite passive microwave data, and ice drift for estimation of the freshwater fluxes into and out of the Weddell Sea. Ice draft is measured with moored upward looking sonars since 1990 along two transects across the Weddell Gyre. One transect, extending from the tip of the Antarctic Peninsula to Kapp Norvegia, was sampled between 1990 and 1994 and covers the flow into and out of the southern Weddell Sea. The other transect, sampled since 1996 and extending from the Antarctic continent northward along the Greenwich meridian, covers the exchange of water masses between the eastern and the western Weddell Sea. In order to relate results obtained during the different time periods, empirical relationships are established between the length of the sea ice season, derived from the satellite passive microwave data and defined as the number of days per year with the sea ice concentration exceeding 15%, and (1) the annual mean ice draft and (2) the annual mean ice volume transport. By using these empirical relationships, estimates of annual mean ice drafts and ice volume transports are derived at all mooring sites for the period February 1979 through February 1999. Wind and current force a westward ice transport in the coastal areas of the eastern Weddell Sea and a northward ice transport in the west. During the 2-year period 1991/1992 the mean ice volume export from the Weddell Sea is (50 ± 19) × 103 m3 s−1. This freshwater export is representative for a longer-term (20-year) mean and exceeds the average amount of freshwater gained by precipitation and ice shelf melt by about 19×103 m3 s−1, yielding an upper bound for the formation rate of newly ventilated bottom water in the Weddell Sea of 2.6 Sv.