Asymmetric behaviour of turbulence kinetic energy in the wake of wind farms caused by the Coriolis effect

The wake behind large wind farms simulated through large-eddy simulations (LES) in shallow conventionally neutral boundary layers is characterised by an asymmetric behaviour in the turbulence kinetic energy (TKE). A streak of increased TKE  forms at one edge of the wake only, and it extends over several tens of kilometres.
A larger-than-expected TKE in the wind farm wake has non-negligible consequences on several aspects, from impacting the life expectancy of turbines in neighbouring wind farms to enhancing mixing of several quantities of the atmospheric boundary layer (ABL) with consequences for the local microclimate.
The primary objective of our work is to determine the physical nature of the increased TKE by means of LES. We initially identify the Coriolis force as the primary symmetry-breaking feature in the resolved physics by observing the TKE streak switching the side of the wake at which it appears when simulating a real wind farm in the German Bight in a shallow northern hemisphere ABL (NH) and in a southern hemisphere ABL (SH).
Moreover,  we implement a method to simulate the same wind farm in three additional fictitious ABLs: one with identical shear profile to NH but without Ekman veer, this isolates the contribution of the Coriolis force induced by the velocity reduction in the wake; an identical ABL to NH but without Coriolis force, to isolate the effect of veer; one ABL where both veer and the Coriolis force are removed. 
Thanks to such a framework, we identify the presence of veer as the necessary conditions for generating a noticeable and long-lasting asymmetry in the wind farm wake TKE. When veer is present, the wind direction inside the wind farm wake is different from that in the free stream. This causes a convergence at the side where the lateral velocity component in the free stream points towards the wind farm wake region. This effect is the most noticeable in the region above the hub height of the rotors.
Such a convergence in the upper part of the ABL induces a larger vertical shear in the main velocity component that causes a larger TKE production.
Our simulation setup allows for further qualitative comparison with satellite-based measurements of the sea-surface collected in the German  Bight, showing asymmetric streaks in the measured friction velocity similar to the modelled TKE. 
Our LES suggest that, in the TKE streak, downward momentum transport is enhanced. Furthermore, a similar pattern to the TKE asymmetry also appears in the friction velocity when using the Charnock parametrisation instead of a constant surface roughness at the domain bottom boundary. Thus, the asymmetric behaviour observed from the satellite could stem from the TKE asymmetry. However, more simulations with different ABLs are required to demonstrate this statement.