A note on evanescent behavior of Arctic thermohaline intrusions
A note on evanescent behavior of Arctic thermohaline intrusions
复制标题
关于北极温盐入侵渐逝行为的注解
DOI：
10.1357/00222400260497499
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
E. Carmack
中科院分区：
文献类型：
--
作者：
David A. Walsh;E. Carmack
温度/盐度交织是北冰洋热盐转变的标志。这些交错的特征，或侵入，当它们从较暖的水域向较冷的水域横向扩散时，其振幅会减小。本文通过考虑非线性状态方程对入侵结构和行为的影响来研究这一现象。分析表明，热膨胀系数(a)的大尺度梯度会引起侵入温度、盐度和流速振幅向较冷水域的空间衰减。空间衰减意味着相邻层之间的再循环流动，这导致侵入体缓慢的垂直传播。a的温度依赖性提供了一种机制，可以在温暖的北极边界流附近捕获入侵，抑制较冷水域的通风。
Temperature/salinity interleaving is a signature of thermohaline transition in the Arctic Ocean. These interleaving features, or intrusions, are observed to decrease in amplitude as they spread laterally from warmer toward cooler water. Here this phenomenon is investigated by considering the effect of a nonlinear equation of state on intrusion structure and behavior. The analysis shows that large-scale gradients of the thermal expansion coefficient (a) can induce a spatial decay of intrusion temperature, salinity, and velocity amplitudes toward cooler water. Spatial decay implies a recirculating flow between adjacent layers, which induces a slow vertical propagation of the intrusions. The temperature-dependence of a provides a mechanism which may act to trap intrusions in the vicinity of warm Arctic boundary currents, inhibiting ventilation of cooler waters.