On the Nature of the Mesoscale Variability in Denmark Strait
On the Nature of the Mesoscale Variability in Denmark Strait
复制标题
丹麦海峡中尺度变率的本质
DOI：
10.1175/jpo-d-16-0127.1
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发表时间：
2017
影响因子：
3.5
通讯作者：
J. Girton
中科院分区：
文献类型：
--
作者：
Wilken‐Jon Appen;Dana Mastropole;R. Pickart;H. Valdimarsson;S. Jónsson;J. Girton
摘要：利用来自丹麦海峡中心系泊点的时间序列数据和跨海床的船上水文剖面集合来阐明海峡中稠密溢流水的中尺度变化。确定了两个主要的、重复出现的特征，称为推注和脉冲。水团是一个大的、弱分层的溢流水透镜体，与气旋旋转和沿流速度适度增加 0.1 m s−1 相关。当团块通过海峡时，溢流层界面高度增加60 m，底部温度降低0.4℃。相比之下，脉冲的特征是反气旋旋转、沿流速度强劲增加 >0.25 m s−1、界面高度降低 90 m，并且没有明显的底部温度信号。据估计，平均每 3.4 (5.4) 天就有一次脉冲通过海峡，其频率没有季节性信号。这两个功能都具有最强的...
AbstractTime series data from a mooring in the center of Denmark Strait and a collection of shipboard hydrographic sections occupied across the sill are used to elucidate the mesoscale variability of the dense overflow water in the strait. Two dominant, reoccurring features are identified that are referred to as a bolus and a pulse. A bolus is a large, weakly stratified lens of overflow water associated with cyclonic rotation and a modest increase in along-stream speed of 0.1 m s−1. When a bolus passes through the strait the interface height of the overflow layer increases by 60 m, and the bottom temperature decreases by 0.4°C. By contrast, a pulse is characterized by anticyclonic rotation, a strong increase in along-stream speed of >0.25 m s−1, a decrease in interface height of 90 m, and no significant bottom temperature signal. It is estimated that, on average, boluses (pulses) pass through the strait every 3.4 (5.4) days with no seasonal signal to their frequency. Both features have the strongest along...