A Modelling Approach for the Assessment of Wave-Currents Interaction in the Black Sea

Abstract

In this study, we investigate wave-currents interaction for the first time in the Black Sea, implementing a coupled numerical system based on the ocean circulation model NEMO v4.0 and the third-generation wave model WaveWatchIII v5.16. The scope is to evaluate how the waves impact the surface ocean dynamics, through assessment of temperature, salinity and surface currents. We provide also some evidence on the way currents may impact on sea-state. The physical processes considered here are Stokes–Coriolis force, sea-state dependent momentum flux, wave-induced vertical mixing, Doppler shift effect, and stability parameter for computation of effective wind speed. The numerical system is implemented for the Black Sea basin (the Azov Sea is not included) at a horizontal resolution of about 3 km and at 31 vertical levels for the hydrodynamics. Wave spectrum has been discretised into 30 frequencies and 24 directional bins. Extensive validation was conducted using in-situ and satellite observations over a five-year period (2015–2019). The largest positive impact of wave-currents interaction is found during Winter while the smallest is in Summer. In the uppermost 200 m of the Black Sea, the average reductions of temperature and salinity error are about −3% and −6%, respectively. Regarding waves, the coupling enhanced the model skill, reducing the simulation error, about −2%.

Assessment of global wave models on regular and unstructured grids using the Unresolved Obstacles Source Term

“…The coupling of waves and circulation was explored in a number of local studies (e.g. Ferrarin et al, 2008;Roland et al, 2009Roland et al, , 2012Babanin et al, 2011;Staneva et al, 2016;Clementi et al, 2017;Causio et al, 2021), and only recently global applications were developed (e.g. Law-Chune et al, 2021).…”

A global unstructured, coupled, high-resolution hindcast of waves and storm surge

“…The coupling of waves and circulation was explored in a number of local studies (e.g. Ferrarin et al, 2008;Roland et al, 2009;Babanin et al, 2011;Roland et al, 2012;Staneva et al, 2016;Clementi et al, 2017;Causio et al, 2021), and only recently global applications were developed (e.g. Law-Chune et al, 2021).…”

Ocean Modelling in Support of Operational Ocean and Coastal Services

“…The book "Ocean Modelling in Support of Operational Ocean and Coastal Services" includes eleven contributions [1][2][3][4][5][6][7][8][9][10][11] to this Special Issue published during 2021-2022. The overall objective of this Special Issue is to draw an updated picture of the heterogeneous challenges that are being addressed in operational oceanographic regional and coastal services, gathering novel and cutting-edge techniques and methods to advance the state of the art of forecast and analysis products.…”

“…Related to the increase in interactions between systems, improving uses of data forcing, and promoting coupling approaches, Causio et al [6] study wave-current interaction for the first time in the Black Sea, implementing a coupled numerical system based on NEMO and WaveWatchIII, evaluating how waves impact surface ocean dynamics, and how ocean currents may impact sea state. Different physical processes are considered in the study (i.e., Stokes-Coriolis force, sea-state-dependent momentum flux, wave-induced vertical mixing, Doppler shift effect, and stability parameter for the computation of effective wind speed).…”