Influence of the ocean surface velocity dependence of the wind stress on the dynamics of the Southern Ocean

该提案的目的是了解表面风应力的表面速度依赖性对南大洋动力学的影响。扩展摘要：在海洋研究中，表面风应力对海洋表面速度的依赖性通常被忽略，因为海洋表面流的速度通常比10米风的速度小至少一个数量级。然而，最近的研究表明，包括海洋表面速度依赖性导致耗散效应，其大小与海洋底部摩擦有关。这种阻尼的效果是特别强的中尺度涡动场导致减少约20%的涡动动能的模型，包括海洋表面速度的依赖性相比，不。在南大洋，中尺度涡动场是影响动力学的重要因素。特别是，一个向南的输送与涡需要对抗北Ekman输送在地面层由于绕极西风。正是这两种相互抵消的效应之间的轻微不平衡，驱动了南大洋的赤道翻转环流（MOC），而这反过来又对全球气候系统，包括碳循环至关重要。该提案的目的是了解将海洋表面速度纳入表面风应力参数化对南大洋动力学的影响。由于我们希望找到中尺度涡旋场的阻尼，因此需要探索这种阻尼对平均流（例如绕极流的强度）和MOC的影响。也有人认为，阻尼的变化在确定海洋中涡流场的变化方面起着一定的作用。因此，了解阻尼的影响对于了解南大洋对上覆风场变化和气候变化的反应非常重要。

The objective of the proposal is to understand the influence of the surface velocity dependence of the surface wind stress on the dynamics of the Southern Ocean. Extended Summary: The dependence of the surface wind stress on the ocean surface velocity is usually neglected in studies of the ocean on the grounds that the speed of the ocean surface current is often at least one order of magnitude smaller than that of the 10 m wind. However, recent studies have shown that including the ocean surface velocity dependence leads to a dissipative effect that is comparable in magnitude to that associated with the bottom friction in the ocean. The effect of this damping is especially strong on the mesoscale eddy field leading to a reduction of around 20% in the eddy kinetic energy in models that include the ocean surface velocity dependence compared to models that do not. In the Southern Ocean, the dynamics depend crucially on the mesoscale eddy field. In particular, a southward transport associated with the eddies is required to counter the northward Ekman transport in the surface layers due to the circumpolar westerly winds. It is the slight imbalance between these two counteracting effects that drives the meridional overturning circulation (MOC) in the Southern Ocean which, in turn, is of major importance for the global climate system, including the carbon cycle. The objective of the proposal is to understand the impact of including the ocean surface velocity in the parameterisation of the surface wind stress on the dynamics of the Southern Ocean. Since we expect to find a damping of the mesoscale eddy field, there is a need to explore the impact of this damping on the mean flow (e.g. the strength of the Circumpolar Current) and on the MOC. It has also been suggested that variations in the damping play a role in determining the variability of the eddy field in the ocean. Understanding the impact of the damping is therefore important for understanding the response of the Southern Ocean to changes in the overlying wind field and to climate change.