THE ANNUAL VARIATION OF WATER MASS STRUCTURE IN THE GULF OF MAINE - 1986-1987
THE ANNUAL VARIATION OF WATER MASS STRUCTURE IN THE GULF OF MAINE - 1986-1987
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DOI：
10.1357/0022240933223828
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发表时间：
1993-02-01
影响因子：
0.5
通讯作者：
IRISH, JD
中科院分区：
文献类型：
--
作者：
BROWN, WS;IRISH, JD
利用5次船载测量和4个系泊台阵的数据遥测，对缅因州海湾主要水团的结构和配置的年变化进行了研究。时间序列观测记录的冷却引起的上层水柱在秋季和随后的混合层加深在西部海湾，主要是在威尔金森盆地，在1987年冬季。异常大量的新鲜斯科舍陆架水流入抑制1987年冬季垂直混合在东部海湾相对于深层混合在西部海湾和周围的威尔金森盆地。这些过程的最终结果是1987年的海湾比1986年的海湾更冷，更新鲜。海湾主要水团厚度的详细历史--即缅因州地表水、缅因州中层水和缅因州底层水--在系泊地点揭示了初夏从东北海峡到乔治盆地和约旦盆地的斜坡和底层水的进展。1987年早春，缅因州中层水占墨西哥湾总水量的近50%。在夏季，东部海湾的缅因州中层水被一个温暖的水团所取代，我们称之为夏季中层水。CTD导出的1987年春夏水团分布图序列记录了（1）缅因州中层水撤退到威尔金森盆地，（2）夏季中层水向西扩散，以及（3）斜坡水流入。一个简单的水团守恒模型表明，缅因州中层水损失的72%以0.21 × 10（6）m3/s的速率流出观测区域，而另外的28%通过与东部海湾的表层水和底层水混合而产生夏季中层水。斜坡水（0.11 x 10（6）M3/s）、底层水（0.03 x 10（6）M3/s）和夏季中层水（0.07 x 10（6）M3/s）的合并流入似乎平衡了4月至7月缅因州中层水的流出。
The annual variation in the structure and disposition of the principal water masses in the Gulf of Maine has been investigated with a set of water property observations using five shipboard surveys and four moored arrays with data telemetry. The time series observations document the cooling-induced destratification of the upper water column during autumn and the subsequent mixed-layer deepening in the western Gulf-primarily in Wilkinson Basin-during winter 1987. Unusually large amounts of fresher Scotian Shelf Water inflow inhibited winter 1987 vertical mixing in the eastern Gulf relative to the deep mixing in and around Wilkinson Basin in the western Gulf. The net result of these processes was a 1987 Gulf that was colder and fresher than the 1986 Gulf. Detailed histories of the thicknesses of the principal water masses in the Gulf-namely, Maine Surface Water, Maine Intermediate Water, and Maine Bottom Water-at the mooring sites reveal the early summer progression of Slope and Bottom Water from the Northeast Channel to Georges Basin and on to Jordan Basin. Maine Intermediate Water made up nearly 50% of the entire volume of the Gulf in early spring 1987. During the summer, Maine Intermediate Water in the eastern Gulf was replaced by a warmer water mass we call Summer Intermediate Water. A spring-summer 1987 sequence of CTD-derived water mass distribution maps documents (1) the retreat of Maine Intermediate Water into Wilkinson Basin, (2) the westward spread of Summer Intermediate Water, and (3) the inflow of Slope Water. A simple water mass conservation model indicates that 72% of the Maine Intermediate Water loss flows out of the observation domain at a rate of 0.21 X 10(6) m3/s, while the other 28% contributes, through mixing with Surface Water and Bottom Water in the eastern Gulf, to the production of Summer Intermediate Water. The combined inflow of Slope Water (0.11 X 10(6) M3/S), Bottom Water (0.03 x 10(6) M3/s), and Summer Intermediate Water (0.07 x 10(6) M3/s) appears to have balanced the April-July outflow of Maine Intermediate Water.