Temperature and salinity fronts at the boundaries of the subarctic-subtropical transition zone in the western Pacific
Temperature and salinity fronts at the boundaries of the subarctic-subtropical transition zone in the western Pacific
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西太平洋亚北极-亚热带过渡带边界的温度和盐度锋面
DOI：
10.1029/jc077i036p07175
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发表时间：
1972
影响因子：
--
通讯作者：
G. I. Roden
中科院分区：
文献类型：
--
作者：
G. I. Roden
本文研究了西太平洋副北极-副热带过渡带边界的锋面特征。亚北极锋出现在42°N附近，其特征是水平温度梯度为8°C/36 km，水平盐度梯度为1‰/36 km，水平声速梯度为28 m sec−1/36 km。在100米以上的水平温度和盐度梯度相互平衡，从而导致密度梯度很小。非常低的流体静力学稳定性发生在亚北极锋面以南，并导致300米深的等温和等盐表层。索法轴的深度在锋面从40米增加到600米，声速沿轴沿着从1464米/秒增加到1478米/秒。副热带锋出现在30°N附近，与副北极锋不同的是，在100米以上存在显著的水平密度梯度。在副热带锋的北面发现了低静流体稳定度，而在南面的区域则有一层以30米为中心的高稳定度薄层。温度的水平梯度为1°C/36 km，盐度的水平梯度为0.1‰/36 km，声速的水平梯度为4 m sec−1/36 km。在154°E处，观察到海水颜色的显著变化。副热带锋和副北极锋都与风应力场、地转流场和热盐通量散度有关。
The frontal features observed at the boundaries of the subarctic-subtropical transition zone in the western Pacific are investigated. The subarctic front occurs near 42°N and is characterized by horizontal temperature gradients of 8°C/36 km, horizontal salinity gradients of 1‰/36 km, and horizontal sound velocity gradients of 28 m sec−1/36 km. The horizontal temperature and salinity gradients in the upper 100 meters balance each other in such a way that the resulting density gradients are small. Very low hydrostatic stabilities occur just south of the subarctic front and result in a 300-meter-deep isothermal and isohaline surface layer. The depth of the Sofar axis increases from 40 to 600 meters at the front, and the sound velocities along the axis increase from 1464 to 1478 m sec−1. The subtropical front occurs in the vicinity of 30°N and differs from the subarctic front by the presence of significant horizontal density gradients in the upper 100 meters. Low hydrostatic stabilities are found just north of the subtropical front, whereas the region to the south is marked by a thin layer of high stability centered at 30 meters. Characteristic horizontal gradients are 1°C/36 km for temperature, 0.1‰/36 km for salinity, and 4 m sec−1/36 km for sound velocity. At 154°E a marked change in the color of the sea was observed. Both the subtropic and the subarctic fronts are related to the wind stress and geostrophic flow fields and to the heat and salt flux divergence.