On the wind stress formulation over shallow waters in atmospheric models
P. A. Jiménez1,2 and J. Dudhia31National Center for Atmospheric Research, Research Applications Laboratory, Boulder, CO, USA 2CIEMAT, División de Energías Renovables, Madrid, Spain 3National Center for Atmospheric Research, Mesoscale and Microscale Meteorology Division, Boulder, CO, USA
Received: 26 Oct 2014 – Accepted for review: 25 Nov 2014 – Discussion started: 18 Dec 2014
Abstract. The wind stress formulation over shallow waters is investigated using year-long observations of the wind profile within the first 100 m of the atmosphere and mesoscale simulations. The model experiments use a range of planetary boundary layer parameterizations in order to quantify the uncertainty related to the turbulent closure assumptions, and thus isolate the dominant influence of the roughness formulation. Results indicate that a positive wind speed bias exists when the common open ocean formulation for roughness is adopted. An alternative formulation consistent with shallow water observations is necessary to reconcile model results with observations, providing the first modeling evidence supporting the increase of surface drag over shallow waters. Including ocean bathymetry as static input data to atmospheric models constitutes an area where further research should be oriented.
Jiménez, P. A. and Dudhia, J.: On the wind stress formulation over shallow waters in atmospheric models, Geosci. Model Dev. Discuss., 7, 9063-9077, doi:10.5194/gmdd-7-9063-2014, 2014.