浅水情形下波浪对大气和海洋底边界层的影响

During the propagation process of ocean waves to the coast, the shoaling effect will alter the action of the sea-surface roughness and sea-bottom stress to water motion. The sea sprays induced by wave breaking in atmospheric bottom boundary layer (ABBL) and suspended sediments induced by waves in oceanic bottom boundary layer (OBBL) will have significant impacts on their stabilities, respectively. Thus the wind stress and sea-bottom stress will be changed. Moreover, ABBL and OBBL will interact on each other in the case of shallow seas. This proposal will investigate the interactions of ocean waves with ABBL and OBBL, and analyze the effects of waves and currents on sea-bottom stress and wind stress. The parameterizations of wind stress and sea-bottom stress in case of shallow seas will be proposed. They will be used to improve the prediction accurate of wave and storm surge models. The results can be applied as theoretical basis and technical support in the disaster prevention and mitigation of our country.

海浪向海岸传播过程中，由于变浅效应会改变海面粗糙度和海底应力对水体的影响，波浪破碎产生的海洋飞沫会影响大气底边界层的稳定性，同样，波浪在海底掀起的泥沙悬浮物会影响海洋底边界层的稳定性，从而改变海面风应力和海底应力。在浅水情形，大气底边界层和海洋底边界层还会发生相互作用。本项目探讨浅水情形下海浪与大气底边界层和海洋底边界层之间的相互作用机制，研究波浪和海流对海底摩擦力和海面风应力的影响，提出浅水情形下海面和海底应力参数化方案，提高浅海海浪和风暴潮模式的预报精度，为我国的减灾和防灾工作提供理论依据和技术支撑。

基于现有的观测数据、数值模式和理论分析，分析了海面拖曳系数与海浪谱宽度以及波龄和波陡之间的关系，提出了海浪谱宽度决定海面拖曳系数的新机制，阐明了涌浪从风浪汲取能量的过程，将拖曳系数与波龄和波陡呈正相关的方案用于WW3海浪数值模式，改进了中国近海波浪模拟精度。通过考虑波浪破碎和波浪轨道速度引起的混合效应，减小了热带气旋强度和半径的预报误差。分别给出了以风速和风海雷诺数为参数的海-气界面气体交换速率公式，考虑了海水温度对海-气界面气体交换的影响，计算了全球海-气界面CO2通量和年际变化。上述工作为海-气界面动量通量和气体通量的准确计算给出了新的途径，为深刻理解海-气相互作用过程以及全球气候变暖预测和碳循环估算提供了新方法。