Fine structure, microstructure, and vertical mixing processes in the upper ocean in the western Weddell Sea
Fine structure, microstructure, and vertical mixing processes in the upper ocean in the western Weddell Sea
复制标题
威德尔海西部上层海洋的精细结构、微观结构和垂直混合过程
DOI：
10.1029/95jc01742
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发表时间：
1995
影响因子：
--
通讯作者：
M. Levine
中科院分区：
文献类型：
--
作者：
R. Robertson;L. Padman;M. Levine
使用 1992 年 2 月至 6 月期间从流冰站获得的数据估算了从暖深水 (WDW) 地下核心到威德尔海西部大陆坡上常年冰覆盖的海面的向上热量通量。通过永久密斜斜，二密热通量估计约为 3 W m -2，主要是由于双扩散对流。没有证据表明剪切驱动的混合在重斜斜中很重要。尽管在暴风雨期间发现峰值热通量高达 15 W m -2 ，但从混合层到冰的估计平均传热率为 1.7 W m -2 。据推测，沿倾斜侵入体的等密度混合也会导致该区域 WDW 的热量损失；然而，我们无法量化与此过程相关的通量。在整个实验过程中，入侵间歇性地发生，但最常见于暖核流和东部陆架改良水的边界附近。这些热通量明显低于平衡威德尔环流热收支所需的盆地平均值 19 W m -2 （Fahrbach 等，1994）。其他研究表明，冰站漂移轨迹以西的陆架过程和东部中旋流中更有活力的双扩散对流可以解释我们对该地区通量估计与基于盆地尺度热收支的估计之间的差异。
The upward flux of heat from the subsurface core of Warm Deep Water (WDW) to the perennially ice-covered sea surface over the continental slope in the western Weddell Sea is estimated using data obtained during February-June 1992 from a drifting ice station. Through the permanent pycnocline the diapycnal heat flux is estimated to be about 3 W m -2, predominantly because of double-diffusive convection. There is no evidence that shear-driven mixing is important in the pycnocline. The estimated mean rate of heat transfer from the mixed layer to the ice is 1.7 W m -2, although peak heat fluxes of up to 15 W m -2 are found during storms. It is hypothesized that isopycnal mixing along sloping intrusions also contributes to the loss of heat from the WDW in this region; however, we are unable to quantify the fluxes associated with this process. Intrusions occur intermittently throughout this experiment but are most commonly found near the boundary of the warm-core current and the shelf-modified water to the east. These heat fluxes are significantly lower than the basin-averaged value of 19 W m -2 (Fahrbach et al., 1994) that is required to balance the heat budget of the Weddell Gyre. Other studies suggest that shelf processes to the west of the ice station drift track and more energetic double-diffusive convection in the midgyre to the east could account for the difference between our flux estimates for this region and those based on the basin-scale heat budget.