FN Archimer Export Format
PT J
TI The upper Bay of Bengal salinity structure in a high-resolution model
BT 
AF BENSHILA, Rachid
   DURAND, Frederic
   MASSON, Sebastien
   BOURDALLE-BADIE, Romain
   DE BOYER MONTEGUT, Clement
   PAPA, Fabrice
AS 1:1;2:2;3:1;4:3;5:4;6:2,5;7:;
FF 1:;2:;3:;4:;5:PDG-ODE-LOS;6:;7:;
C1 UPMC, CNRS, MNHN, LOCEAN IPSL,IRD, Paris, France.
   IRD CNRS CNES UPS, LEGOS, Toulouse, France.
   MERCATOR Ocean, Parc Technol Canal, Ramonville St Agne, France.
   IFREMER, LOS, F-29280 Brest, France.
   Indian Inst Sci, IFCWS, IRD IISc Joint Int Lab, Indo French Cell Water Sci, Bangalore 560012, Karnataka, India.
C2 UNIV PARIS 06, FRANCE
   LEGOS, FRANCE
   MERCATOR OCEAN, FRANCE
   IFREMER, FRANCE
   INDIAN INST SCI, INDIA
SI BREST
SE PDG-ODE-LOS
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
IF 2.927
TC 68
UR https://archimer.ifremer.fr/doc/00168/27925/26199.pdf
LA English
DT Article
DE ;Salinity;Bay of Bengal;Export of fresh water plume;High resolution ocean modeling
AB Salinity in the Bay of Bengal is highly heterogeneous, with extremely fresh waters found at the surface in the Northern part of the basin, and saltier waters at subsurface as well as to the south. This paper investigates the seasonal structure of sea surface salinity of the Bay in a regional high-resolution model forced by ERA-Interim reanalysis and various precipitation products. Surface circulation is believed to drive the spreading of northern Bay of Bengal fresh waters to the rest of the Indian Ocean. We first present a series of experiments to infer the sensitivity of modeled circulation to various numerical choices. Surface circulation is found to be sensitive to the horizontal resolution of the model, with the 1/12° version appearing much more realistic than the 1/4° version. The sidewall boundary condition is also drastically influencing the characteristics of the western boundary current simulated. We then investigate the sensitivity of the salinity response to the various precipitation products. We observe that ERA-Interim excess precipitation induces a fresh bias in the surface salinity response. Spaceborne precipitation products are more satisfactory. We then identify the pathways of the northern Bay freshwater mass, based on passive tracers experiments. Our model suggests that over timescales of a few months, vertical exchanges between the upper fresh layer and the underlying saltier layer appear to be the main export pathway for the freshwater. The horizontal circulation within the mixed layer also acts to convey fresh waters out of the Bay at these timescales, but in a lesser quantity compared to the vertical export. Beyond its intrinsic interest for the understanding of Bay of Bengal physics, this study highlights the need for a careful design of any realistic numerical model, in three key aspects: the choice of the resolution of the model, the choice of the sub-grid scale parameterizations, and the choice of the forcing fluxes.
PY 2014
PD FEB
SO Ocean Modelling
SN 1463-5003
PU Elsevier Sci Ltd
VL 74
UT 000330576400003
BP 36
EP 52
DI 10.1016/j.ocemod.2013.12.001
ID 27925
ER

EF