Deepwater overflow through Luzon Strait
Deepwater overflow through Luzon Strait
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DOI：
10.1029/2005jc003139
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发表时间：
2006-01-10
影响因子：
3.6
通讯作者：
Whitehead, JA
中科院分区：
文献类型：
--
作者：
Qu, TD;Girton, JB;Whitehead, JA
[1]本研究利用所有可获得的水文资料，探讨中国南海及邻近太平洋的水属性分布。分析表明，在1500 m以下，存在一个持续的斜压压力梯度驱动气流从太平洋经吕宋海峡进入南海。将假定位涡为零、海底平坦的水力学理论应用于吕宋海峡，得出的输送量估计值为2.5 Sv（1 Sv = 10（6）m（3）s（-1））。这一结果的一些含义包括：（1）在中国南海深海的停留时间不到30年，（2）平均底扩散率高达10（-3）m（2）s（-1），（3）深海上升流速率约为3 × 10（-6）m（-1）。这些量与基于耗氧速率的停留时间一致。所有流入的水在离开盆地之前必须升温，这一事实意味着这个边缘海有助于推动北太平洋纬向翻转环流的水团转变。南海海盆内的密度分布表明，一个气旋性的深边界流系统，可以预期的溢出驱动的深海环流。
[1] This study examines water property distributions in the deep South China Sea and [adjoining Pacific Ocean using all available hydrographic data. Our analysis reveals that below about 1500 m there is a persistent baroclinic pressure gradient driving flow from the Pacific into the South China Sea through Luzon Strait. Applying hydraulic theory with assumptions of zero potential vorticity and flat bottom to the Luzon Strait yields a transport estimate of 2.5 Sv ( 1 Sv = 10(6) m(3) s(-1)). Some implications of this result include: ( 1) a residence time of less than 30 years in the deep South China Sea, ( 2) a mean diapycnal diffusivity as large as 10(-3) m(2) s(-1), and (3) an abyssal upwelling rate of about 3 x 10(-6) m s(-1). These quantities are consistent with residence times based on oxygen consumption rates. The fact that all of the inflowing water must warm up before leaving the basin implies that this marginal sea contributes to the water mass transformations that drive the meridional overturning circulation in the North Pacific. Density distributions within the South China Sea basin suggest a cyclonic deep boundary current system, as might be expected for an overflow-driven abyssal circulation.