夏季渤海海峡大小潮影响下水体温盐浊分布特征及其水动力机制

渤海海峡沉积物输运及水体温盐分布特征与水体层化混合程度密切相关,大潮时期水体混合程度比小潮时期强,使得水体温盐分布自南向北、自底向上都存在着明显的大小潮差异。老铁山水道附近中低层入侵的高盐低温的黄海水团受混合作用影响,在大潮时期明显比小潮时期垂向作用范围大,且跃层明显;自北隍城岛向南,受渤海沿岸流淡水影响,水体盐度逐渐降低,温度逐渐升高,表层存在明显温盐跃层,且小潮跃层厚度较大。受混合作用影响,中底层水体浊度在大潮时期基本高于小潮时期,底层泥沙主要来自海底底质泥沙再悬浮,自南向北底质泥沙粒度渐粗,因此,底层浊度自南向北逐渐降低。

DISTRIBUTION OF TURBIDITY AND WATER THERMOHALINE PATTERN AND ITS DYNAMICAL MECHANISM UNDER THE INFLUENCE OF SUMMER SPRING AND NEAP TIDES

The sediment distribution and the water thermohaline structure are closely related to the mixing of the stratifiedwater in the Bohai Strait. The mixing level of the water column in spring tides is stronger than that in neap tides, that makes significant spring-neap difference in water thermohaline structure from south to north and from the bottom to the surface. The vertical spread of the Yellow Sea water mass was larger in spring tide than in neap tide in the middle and lower water layers near the Laotieshan channel, influenced by the water mixing effect, and the water thermocline and halocline here are also more apparent in spring tide. From the North Huangcheng Island to the south, affected by fresh water of the Bohai Coastal Current, the water salinity decreases gradually, while the water temperature increases. The thermocline and halocline are both clear in the surface layer. The thickness of the thermocline and halocline in neap tide was larger than that in spring tide. In addition, the water turbidity in the middle and bottom layer was higher in spring tide than in neap tide. For the reason that the bottom suspended sediment is derived from the resuspension of the seabed sediment and the sediment grain size increased gradually from south to north, the bottom turbidity decreased gradually from south to north.