Circulation and Transport in the Western Boundary Currents at Cape Farewell, Greenland
Circulation and Transport in the Western Boundary Currents at Cape Farewell, Greenland
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DOI：
10.1175/2009jpo4160.1
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发表时间：
2009-08-01
影响因子：
3.5
通讯作者：
McDonagh, E. L.
中科院分区：
文献类型：
--
作者：
Holliday, N. P.;Bacon, S.;McDonagh, E. L.
2005年8 - 9月，对格陵兰岛普惠角附近的西边界流环流和体积输送进行了全深度水文和速度测量。西边界流在伊尔明格海向南输送40.5 +/- 8.1 Sv (Sv相当于10(6)m(3) s(-1))，在拉布拉多海向北输送53.8 +/- 10.8 Sv。深西部边界流（DWBC，定义为潜在密度大于27.80 kg m（-3）的水）在伊尔明格海向南输送12.3 +/- 2.5 Sv。告别角以南的深水运输减少，水流方向由南向北（南角）改变。在erik山脊上的一段，DWBC向西输送8.7 +/- 1.7 Sv。南角的输运减少与最深层内的速度下降和最含盐的深水类型的体积损失有关。观测结果表明，西部浅部和深层边界流的路径在南角分岔。拉布拉多海东部下游深水输运向北增加至19.7 +/- 3.9 Sv，增加了更密集的再循环深水。并结合DWBC的配套电流计测量结果，讨论了半透光测量结果的代表性。
The circulation and volume transports in the western boundary currents around Cape Farewell, Greenland, are derived from full-depth hydrographic and velocity measurements from August-September 2005. The western boundary currents from surface to seafloor transport 40.5 +/- 8.1 Sv (Sv equivalent to 10(6) m(3) s(-1)) southward in the Irminger Sea, and 53.8 +/- 10.8 Sv northward in the Labrador Sea. The Deep Western Boundary Current (DWBC, defined as water with potential density greater than 27.80 kg m(-3)) transports 12.3 +/- 2.5 Sv southward in the Irminger Sea. The deep water transport is reduced south of Cape Farewell, where it changes flow direction from southward to northward ( the south corner). At a section over the Eirik Ridge, a bathymetric feature extending southwest of Cape Farewell, the DWBC transports 8.7 +/- 1.7 Sv westward. The reduction in transport at the south corner is associated with decreased velocities within the deepest layers and the volumetric loss of the most saline deep water types. The observations suggest that the paths of the shallow and deep western boundary currents diverge at the south corner. Downstream in the eastern Labrador Sea the deep water transport is increased to 19.7 +/- 3.9 Sv northward, with the addition of recirculating denser deep waters. The representativeness of the results from the semisynoptic survey is discussed with reference to companion current meter measurements of the DWBC.