Abstract
Abstract. The Mistral and Tramontane are mesoscale winds in southern France and above the Western Mediterranean Sea. They are phenomena well suited for studying channeling effects as well as atmosphere–land/ocean processes. This sensitivity study deals with the influence of the sea surface roughness length parameterizations on simulated Mistral and Tramontane wind speed and wind direction. Several simulations with the regional climate model COSMO-CLM were performed for the year 2005 with varying values for the Charnock parameter α. Above the western Mediterranean area, the simulated wind speed and wind direction pattern on Mistral days changes depending on the parameterization used. Higher values of α lead to lower simulated wind speeds. In areas, where the simulated wind speed does not change much, a counterclockwise rotation of the simulated wind direction is observed.
Highlights
The Mistral and Tramontane are winds in southern France, which are channeled by the Rhône and Aude valleys before blowing over the Mediterranean Sea
This sensitivity study investigates the influence of the sea surface roughness length parameterization on the patterns of Mistral and Tramontane wind speeds and wind directions above the Mediterranean Sea in CCLM simulations
Three values for the Charnock parameter α have been tested within the regional climate model COSMO-CLM
Summary
The Mistral and Tramontane are winds in southern France, which are channeled by the Rhône and Aude valleys before blowing over the Mediterranean Sea. On Mistral and Tramontane days, simulations with the regional climate model COSMO-CLM (CCLM) with 0.088◦ grid spacing were found to be able to simulate Mistral and Tramontane wind patterns slightly overestimating 10 m wind speed compared to satellite and buoy observations (Obermann et al, 2016). This sensitivity study investigates the influence of the sea surface roughness length parameterization on the patterns of Mistral and Tramontane wind speeds and wind directions above the Mediterranean Sea in CCLM simulations. A complete description of the ocean-atmosphere interaction and, the sea surface roughness, should account for ocean currents, waves, and interaction between these phenomena (Carniel et al, 2016; Ricchi et al, 2016)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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
