Abstract
Abstract. In this contribution the wind jet dynamics in the northern margin of the Ebro River shelf (NW Mediterranean Sea) are investigated using coupled numerical models. The study area is characterised by persistent and energetic offshore winds during autumn and winter. During these seasons, a seaward wind jet usually develops in a ∼ 50 km wide band offshore. The COAWST (Coupled Ocean–Atmosphere–Wave–Sediment Transport) modelling system was implemented in the region with a set of downscaling meshes to obtain high-resolution meteo-oceanographic outputs. Wind, waves and water currents were compared with in situ observations and remote-sensing-derived products with an acceptable level of agreement. Focused on an intense offshore wind event, the modelled wind jet appears in a limited area offshore with strong spatial variability. The wave pattern during the wind jet is characterised by the development of bimodal directional spectra, and the ocean circulation tends to present well-defined two-layer flow in the shallower region (i.e. inner shelf). The outer shelf tends to be dominated by mesoscale dynamics such as the slope current. Due to the limited fetch length, ocean surface roughness considering sea state (wave–atmosphere coupling) modifies to a small extent the wind and significant wave height under severe cross-shelf wind events. However, the coupling effect in the wind resource assessment may be relevant due to the cubic relation between the wind intensity and power.
Highlights
Coastal areas are often characterised by highly variable and heterogeneous wind, wave and current conditions, which make the numerical prediction of the meteo-oceanographic processes difficult
After the introduction (Sect. 1), in Sect. 2 (Methods) we describe the study area, the COAWST model implementation and the wind jet event selected to investigate in detail the meteo-oceanographic dynamics
The correlation coefficient (R) is almost 0.8 and the root mean square error (RMSE) and the bias are smaller than the mean and the standard deviation obtained from the observations
Summary
Coastal areas are often characterised by highly variable and heterogeneous wind, wave and current conditions, which make the numerical prediction of the meteo-oceanographic processes difficult. Despite the relatively limited fetch in the wind jet region, the wave height can be relevant, interacting with bimodal features (Shimada and Kawamura, 2006). In this sense, several contributions have highlighted the influence of variable wind conditions in relatively smallscale areas (such as wind jet), influencing wind–wave generation (Shimada and Kawamura, 2006; Bolaños-Sanchez et al, 2007; Alomar et al, 2014) or modifying ocean circulation patterns (Csanady, 1980; Zhai and Bower, 2013; Schaeffer et al, 2011; Klaicet al., 2011)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
