A model study of Circumpolar Deep Water on the West Antarctic Peninsula and Ross Sea continental shelves
A model study of Circumpolar Deep Water on the West Antarctic Peninsula and Ross Sea continental shelves
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DOI：
10.1016/j.dsr2.2010.11.013
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发表时间：
2011-07-01
影响因子：
3
通讯作者：
Smith, Walker O., Jr.
中科院分区：
文献类型：
--
作者：
Dinniman, Michael S.;Klinck, John M.;Smith, Walker O., Jr.
相对温暖、营养丰富的环极深水（CDW）向南极大陆架的输送对物理和生物过程有重要影响。然而，CDW的特点沿着大陆架断裂，以及发生了什么事，一旦它已经平流到大陆架上，空间上不同。在本研究中，高分辨率（4-5公里）的区域模式的罗斯海和西南极半岛沿海海洋的CDW传输的差异进行了比较，模型比较非常好，从这两个地区的观测。检查通量不仅热，而且模拟的“染料”代表COW，表明在这两种情况下，COW跨越大陆架断裂的具体位置主要由水深测量，但最终洪水大部分的货架。玛格丽特海槽的侵入频率约为100%。2-3每月，类似于最近的系泊观测。观测到沿沿着陆架断裂风应力和通过玛格丽特海槽的跨陆架断裂染料通量之间的显著相关性，表明侵入体至少部分与短持续时间的风事件有关。罗斯和南极半岛陆架上的CDW侵入体之间的主要区别在于，在罗斯海，CDW与表面沃茨有更强烈的混合，特别是在西部高盐度陆架水形成的地方。该模型表明，COW移动横跨南极半岛大陆架的冰架的底部不仅是温暖的初始和旅行的距离比平流对罗斯冰架的底部，但它也受到较少的垂直混合与表面沃茨，这保存了热量可平流冰架下。这种垂直混合的差异也可能导致从COW到上层水柱的营养物供应的差异，从而调节对地表生物地球化学过程的影响。(C)2010爱思唯尔有限公司版权所有。
Transport of relatively warm, nutrient-rich Circumpolar Deep Water (CDW) onto continental shelves around Antarctica has important effects on physical and biological processes. However, the characteristics of the CDW along the shelf break, as well as what happens to it once it has been advected onto the continental shelf, differ spatially. In the present study high resolution (4-5 km) regional models of the Ross Sea and the West Antarctic Peninsula coastal ocean are used to compare differences in CDW transport The models compared very well with observations from both regions. Examining the fluxes not only of heat, but also of a simulated "dye" representing COW, shows that in both cases COW crosses the shelf break in specific locations primarily determined by the bathymetry, but eventually floods much of the shelf. The frequency of intrusions in Marguerite Trough was ca. 2-3 per month, similar to recent mooring observations. A significant correlation between the along shelf break wind stress and the cross shelf break dye flux through Marguerite Trough was observed, suggesting that intrusions are at least partially related to short duration wind events.The primary difference between the CDW intrusions on the Ross and west Antarctic Peninsula shelves is that there is more vigorous mixing of the CDW with the surface waters in the Ross Sea, especially in the west where High Salinity Shelf Water is created. The models show that the COW moving across the Antarctic Peninsula continental shelf towards the base of the ice shelves not only is warmer initially and travels a shorter distance than that advected towards the base of the Ross Ice Shelf, but it is also subjected to less vertical mixing with surface waters, which conserves the heat available to be advected under the ice shelves. This difference in vertical mixing also likely leads to differences in the supply of nutrients from the COW into the upper water column, and thus modulates the impacts on surface biogeochemical processes. (C) 2010 Elsevier Ltd. All rights reserved.