Ocean waves can spatiotemporally redistribute the momentum flux at the air‐sea interface, which varies with the sea state. Traditional atmosphere‐ocean coupled systems assume the ocean‐side stress (τ_oc) to be identical to the air‐side stress (τ_a); consequently, the role of ocean waves is neglected. In this study, the wave impacts on the air‐sea momentum flux are investigated based on 1‐year high‐resolution model simulations in the Baltic Sea using an atmosphere‐wave coupled model (Uppsala University‐Coupled Model, UU‐CM). The simulation results show that τ_oc can differ significantly from τ_a in both direction and magnitude. The direction difference between τ_oc and τ_a (DD(τ_oc, τ_a)) and the normalized momentum flux () decrease with increasing inverse wave age. In general, and DD(τ_oc, τ_a) are pronounced under wind‐following swell and wind‐crossing swell conditions, respectively. The occurrence frequencies of large and DD(τ_oc, τ_a) are higher nearer the coast; statistically, both decrease significantly with increasing water depth because of the joint effect of dissipation processes. Based on four selected areas, we find that alongshore winds (winds blowing parallel to the coastline) are favorable for large angular differences between τ_oc and τ_a (DD(τ_oc, τ_a) > 5°). However, onshore winds predominate at . The τ_a in the wave model is generally less than that obtained from the atmospheric model under low‐moderate wind conditions if the wave model feeds only the Charnock coefficient (roughness length) back to the atmospheric model in coupled systems.

中文翻译：

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海空界面动量通量平衡

海浪可以在时空上重新分配气海界面处的动量通量，该动量通量随海况而变化。传统的大气海洋耦合系统假设海洋侧应力（τ _OC）以等同于空气侧应力（τ_一个）; 因此，海浪的作用被忽略了。在这项研究中，基于波罗的海的1年高分辨率模型模拟，使用大气-波耦合模型（乌普萨拉大学耦合模型，UU-CM），研究了波浪对空气-海洋动量通量的影响。仿真结果表明，τ _OC可以显著不同于τ_一个在两个方向和大小。τ之间的方向差_OC和τ_一个（ DD（ τ _OC， τ_一）），并归一化的动量通量（）减少随着逆波的年龄。一般情况下，和DD（ τ _OC， τ_一个）的风以下膨胀和风力交叉溶胀条件下分别显着。的大出现频度和DD（ τ _OC， τ_一个）靠近海岸更高；从统计上讲，由于耗水过程的共同影响，两者都随着水深的增加而显着下降。基于四个选择的区域，我们发现，近岸风速（风平行于海岸线吹）是用于之间的大角度差有利τ _OC和τ_一个（DD（τ _OC，τ_一）> 5°）。但是，陆风主要在处。该τ_一 如果波浪模型仅将Charnock系数（粗糙度长度）反馈给耦合系统中的大气模型，则波浪模型中的“海浪”通常小于在低中风条件下从大气模型获得的海浪。