TY - JOUR
T1 - Ocean response to strong precipitation events in the Gulf of Lions (northwestern Mediterranean Sea)
T2 - A sensitivity study
AU - Brossier, Cindy Lebeaupin
AU - Béranger, Karine
AU - Drobinski, Philippe
N1 - Funding Information:
This work is a contribution to the MORCE-MED project funded by the GIS (Groupement d’Intérêt Scientifique) “Climat, Environnement et Société, with granted access to the HPC resources of IDRIS (under allocation i2009010227). The authors are grateful to Charles Deltel (LOCEAN, INRIA), Romain Bourdallé-Badie, and Jonathan Beuvier (Mercator-Ocean) for their useful help about the MED12 model. Finally, the authors would like to thank the two anonymous reviewers that help us to deeply improve this paper.
PY - 2012/2/1
Y1 - 2012/2/1
N2 - The Mediterranean Sea is a region of intense air-sea interactions, with in particular strong evaporation over sea which drives the thermohaline circulation. The Mediterranean region is also prone to strong precipitation events characterized by low spatial extent, short duration, and high temporal variability. The impacts of intense offshore precipitation over sea, in the Gulf of Lions which is a spot for winter deep convection, are investigated using four sensitivity simulations performed at mesoscale resolution with the eddy-resolving regional ocean model NEMO-MED12. We use various atmospheric fields to force NEMO-MED12, downscaled from reanalyses with the non-hydrostatic mesoscale Weather Research and Forecasting model but differing in space resolutions (20 and 6.7 km) or in time frequencies (daily and three-hourly). This numerical study evidences that immediate, intense, and rapid freshening occurs under strong precipitation events. The strong salinity anomaly induced extends horizontally (≃50 km) as vertically (down to 50 m) and persists several days after strong precipitation events. The change in the space resolution of the atmospheric forcing modifies the precipitating patterns and intensity, as well as the shape and the dynamics of the low-salinity layer formed are changed. With higher forcing frequency, shorter and heavier precipitation falls in the ocean in the center of the Gulf of Lions, and due to a stronger vertical shear and mixing, the low-salinity anomaly propagates deeper.
AB - The Mediterranean Sea is a region of intense air-sea interactions, with in particular strong evaporation over sea which drives the thermohaline circulation. The Mediterranean region is also prone to strong precipitation events characterized by low spatial extent, short duration, and high temporal variability. The impacts of intense offshore precipitation over sea, in the Gulf of Lions which is a spot for winter deep convection, are investigated using four sensitivity simulations performed at mesoscale resolution with the eddy-resolving regional ocean model NEMO-MED12. We use various atmospheric fields to force NEMO-MED12, downscaled from reanalyses with the non-hydrostatic mesoscale Weather Research and Forecasting model but differing in space resolutions (20 and 6.7 km) or in time frequencies (daily and three-hourly). This numerical study evidences that immediate, intense, and rapid freshening occurs under strong precipitation events. The strong salinity anomaly induced extends horizontally (≃50 km) as vertically (down to 50 m) and persists several days after strong precipitation events. The change in the space resolution of the atmospheric forcing modifies the precipitating patterns and intensity, as well as the shape and the dynamics of the low-salinity layer formed are changed. With higher forcing frequency, shorter and heavier precipitation falls in the ocean in the center of the Gulf of Lions, and due to a stronger vertical shear and mixing, the low-salinity anomaly propagates deeper.
KW - Mediterranean Sea
KW - Resolution impact
KW - Stratification
KW - Strong precipitation
UR - https://www.scopus.com/pages/publications/84861097230
U2 - 10.1007/s10236-011-0502-8
DO - 10.1007/s10236-011-0502-8
M3 - Article
AN - SCOPUS:84861097230
SN - 1616-7341
VL - 62
SP - 213
EP - 226
JO - Ocean Dynamics
JF - Ocean Dynamics
IS - 2
ER -