Study on Modelling the Air-Sea Boundary Processes in Unsteady and Non-Uniform Field by Expanding the TOHOKU Wave Model

模拟非定常、非均匀场中的海气边界过程是阐明大尺度海气相互作用的一项基本任务。本课题要解决的问题包括：(1)阐明散体公式中的阻力和其他系数，或气流粗糙度参数Z&lt；@D20@&>D2，除风条件外，还与海况或风浪条件的关系；(2)在海面蒸发和热交换的定量表达式中适当地考虑海-水滴的影响；(3)将上述两项与适当的波浪预报模式相结合，建立海气通量大范围分布的表达方式。关于第(1)项，已阐明了纯风浪的局部平衡的详细结构，即风浪、湍流、空气和水的摩擦速度之间的关系。将局地平衡概念应用于悉尼大学一位同事获得的巴斯海峡大风和风浪条件下的资料，有力地支持了我们早先提出的Z&lt；@D20@&gt；d1=Gamma u&lt；@D2*@&gt；D2/sigma&lt；@D2p@&gt；D2，其中Gamma=0.025，u&lt；@D2*@&gt；D2是空气摩擦速度，@D2p@&gt；D2是风浪谱峰值角频率。关于第(2)项，给出了风浪表面海水水滴在海面附近的产生率和浓度的新公式。对于第(3)项，我们的东北波模型在更复杂的条件下的应用已经取得了一些进展。

Modelling of the air-sea boundary processes in unsteady, non-uniform field is a fundamental task for the elucidation of large-scale air-sea interactions. Elements to be solved for this subject include (1) to elucidate the dependence of drag and other coefficients in Bulk formulas, or the air-flow roughness parameter, Z<@D20@>D2, on the sea state or wind wave conditions in addition to the wind conditions; (2) to include properly the effect of sea-water droplets in quantitative expressions of sea-surface evaporation and the heat exchange; (3) to establish the way of expression of broad-area distribution of air-sea fluxes by incorporating the above two items together with an appropreate wave prediction model. As to the item (1), detailed structure of the local equilibrium, or the relations among wind waves, turbulence, air and water friction velocity, has been elucidated for pure wind waves. By using the local equilibrium concept, applied to data under strong wind and wind-wave conditions in Bass Strait obtained by a Sydney University colleague, a strong support has been given for our earlier proposal of Z<@D20@>D1 = gamma u<@d2*@>d2/sigma<@d2p@>d2, where gamma = 0.025, u<@d2*@>d2 is the air friction velocity, and sigma<@d2p@>d2 the wind-wave spectral peak angular frequency. For item (2), a new formulation has been given for the rate of production and concentration near the sea surface of sea-water droplets from wind-wave surfaces. For item (3), some progress has been made for the application of our TOHOKU Wave Model to more complicated conditions.