夏季黄河入海径流对黄河口及附近海域环流影响的数值研究

基于区域海洋模式ROMS,建立了一个三维非线性斜压浅海模式,考虑了包括径流、风场、海面热交换以及黄渤海环流等因素,研究了夏季8月份黄河入海径流量对黄河口及附近海域环流结构的影响。数值实验较好地佐证了黄河冲淡水的"北偏"现象,并很好的体现了冲淡水对河口附近海域环流结构的影响。数值研究表明:黄河入海径流量对河口附近海域环流结构有显著影响,径流越大冲淡水向北-西北方向偏转越明显,同时流轴中心余流流速也显著增大;莱州湾顺时针环流受黄河入海径流影响显著,径流量越大越不利于该环流的发育和维持,而径流量越小环流越稳定;径流量越大导致河口附近海域表层余流加大,余流垂向梯度得到加强,底部补偿流增强,河口垂向环流越明显。

Numerical study of the circulation influenced by runoff input in the Huanghe (Yellow) River Estuary and adjacent waters in summer

A 3-D nonlinear baroclinic ocean model based on Regional Ocean Modeling System (ROMS) has been set up, with the consideration of river discharge, wind, sea surface heat flux and regional ocean circulation to carry out numerical studies of the circulation pattern influenced by runoff input in the Huanghe (Yellow) River Estuary and adjacent waters in summer month of August. The numerical simulations confirm the viewpoint of northward rotation of Huanghe diluted water well, and present the effect of river discharge on circulation in the vicinity of Huanghe Estuary meanwhile. The numerical results show that Huanghe diluted water affects circulation in region of Huanghe Estuary significantly, and the residual speed markedly increased alone with the strengthened northerly rotation as the result of increasingly discharge. The circulation pattern in Laizhou Bay is under almost total controls of Huanghe runoff, and this local circulation is apt to develop and maintain with smaller order of magnitude of Huanghe discharge, vice versa. Surface residual currents tend to increase apparently with larger volume of diluted water, leading to enhanced vertical gradient of residual currents that can cause much stronger bottom flow and vertical circulation near river estuary.