Turbulent vertical velocity measurements are scarce in regions prone to convection such as the Labrador Sea, which hinders our understanding of deep convection dynamics. Vertical velocity, $w$, is retrieved from wintertime glider deployments in the convective region. From $w$, downward convective plumes of dense waters are identified. These plumes only cover a small fraction of the convective area. Throughout the convective area, the standard deviation of $w$ agrees with scaling relations for the atmospheric surface and boundary layers. It initially depends on surface buoyancy loss in winter, and later, on wind stress after mid-March. Both periods are characterized by positive turbulent vertical buoyancy flux. During convective periods in winter, the positive buoyancy flux is mostly forced by surface heat loss. After mid-March, when buoyancy loss to the atmosphere is reduced, the positive buoyancy flux results from a restratifying upward freshwater flux, potentially of lateral origins and without much atmospheric influence.

中文翻译：

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拉布拉多海对流中的湍流垂直速度


在拉布拉多海等易发生对流的地区，湍流垂直速度测量很少，这阻碍了我们对深对流动力学的理解。垂直速度 $w$ 是从对流区域的冬季滑翔机部署中检索的。从 $w$ 开始，确定了密集水域的向下对流羽流。这些羽流只覆盖了对流面积的一小部分。在整个对流区，$w$ 的标准差与大气表层和边界层的缩放关系一致。它最初取决于冬季的表面浮力损失，后来取决于 3 月中旬之后的风应力。这两个时期的特点是正湍流垂直浮力通量。在冬季的对流期间，正浮力通量主要是由表面热量损失引起的。3 月中旬之后，当大气中的浮力损失减少时，正浮力通量是由重新分层的向上淡水通量产生的，可能是横向来源的，没有太大的大气影响。