Air–Sea Interaction in the Ligurian Sea: Assessment of a Coupled Ocean–Atmosphere Model Using In Situ Data from LASIE07

Abstract

In situ experimental data and numerical model results are presented for the Ligurian Sea in the northwestern Mediterranean. The Ligurian Sea Air-Sea Interaction Experiment (LASIE07) and LIGURE2007 experiments took place in June 2007. The LASIE07 and LIGURE2007 data are used to validate the Coupled Ocean-Atmosphere Mesoscale Prediction System (COAMPS) 1 developed at the Naval Research Laboratory. This system includes an atmospheric sigma coordinate, nonhydrostatic model, coupled to a hydrostatic sigma-z-level ocean model (Navy Coastal Ocean Model), using the Earth System Modeling Framework (ESMF).A month-long simulation, which includes data assimilation in the atmosphere and full coupling, is compared against an uncoupled run where analysis SST is used for computation of the bulk fluxes. This reveals that COAMPS has reasonable skill in predicting the wind stress and surface heat fluxes at LASIE07 mooring locations in shallow and deep water. At the LASIE07 coastal site (but not at the deep site) the validation shows that the coupled model has a much smaller bias in latent heat flux, because of improvements in the SST field relative to the uncoupled model. This in turn leads to large differences in upper-ocean temperature between the coupled model and an uncoupled ocean model run.

Sensitivity of a Mediterranean Tropical-Like Cyclone to Different Model Configurations and Coupling Strategies

“…The substantial difference between the WRF standalone case and the AO run is that in the latter, the SST provided by ROMS is at high resolution and updated frequently in a dynamically consistent way. In fact, the heat fluxes that WRF sends to ROMS are based on the SST that WRF receives from ROMS, therefore providing a consistent approach for energy and momentum [18,19,27,47]. In standalone configurations, the fluxes are calculated offline independently by the atmospheric and the ocean models, generating inconsistencies between the two representations.…”

SURFEX v8.0 interface with OASIS3-MCT to couple atmosphere with hydrology, ocean, waves and sea-ice models, from coastal to global scales

“…COAMPS also includes nesting capability in the two components and a coupled data assimilation scheme. This system was used in particular over the Adriatic Sea and the Ligurian Sea to evaluate the air-sea interactions during strong wind events, bora and mistral, with resolutions of up to 4 km in the atmosphere and 2 km in the ocean (Pullen et al, 2006(Pullen et al, , 2007Small et al, 2011Small et al, , 2012. A configuration of COAMPS, named COAMPS-TC, was also specifically designed to improve tropical cyclone forecasts (Doyle et al, 2014).…”

The M3A network of open ocean observatories in the Mediterranean Sea

“…The system was validated during the Ligurian Air Sea Interaction Experiment (LASIE) [41] carried out in the period June-July 2007 when a Datawell Directional Waverider was deployed about 4 km far from the W1-M3A observatory. The developed approach was validated up to sea state 5 and the correlation coefficient was 0.97 and 0.99 for the wave height and the wave period, respectively.…”

“…The availability of a complete set of meteorological measurements including long-wave and short wave radiation, coupled with sea surface temperature and the amount of rainfall allows monitoring the dynamics of heat fluxes into the ocean in terms of its latent and sensible components as well as the heat fluxes and the momentum fluxes due to rain [41]. Multi-annual time series (Fig.…”