FN Archimer Export Format
PT J
TI Cyclogeostrophic balance in the Mozambique Channel
BT 
AF PENVEN, Pierrick
   HALO, Issufo
   POUS, Stephane
   MARIE, Louis
AS 1:1,2,3;2:2,4;3:2,3,5;4:6;
FF 1:;2:;3:;4:PDG-ODE-LPO;
C1 UBO, IFREMER, CNRS, Lab Phys Oceans,UMR 6523,IRD, Plouzane, France.
   Univ Cape Town, Dept Oceanog, ZA-7925 Cape Town, South Africa.
   Univ Cape Town, IRD, LMI ICEMASA, ZA-7925 Cape Town, South Africa.
   Univ Cape Town, Nansen Tutu Ctr Marine Environm Res, ZA-7925 Cape Town, South Africa.
   UPMC, Lab Oceanog & Climat Expt & Approches Numer, CNRS, UMR 7159,IRD,MHN, Paris, France.
   IFREMER, UBO,CNRS, Lab Phys Oceans,UMR 6523,IRD, Plouzane, France.
C2 IRD, FRANCE
   UNIV CAPE TOWN, SOUTH AFRICA
   UNIV CAPE TOWN, SOUTH AFRICA
   UNIV CAPE TOWN, SOUTH AFRICA
   UNIV PARIS 06, FRANCE
   IFREMER, FRANCE
SI BREST
SE PDG-ODE-LPO
   PDG-ODE-DYNECO-PHYSED
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-p187
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
TC 28
UR https://archimer.ifremer.fr/doc/00175/28617/27045.pdf
LA English
DT Article
AB Three methods are proposed for the inclusion of inertia when deriving currents from sea surface height (SSH) in the Mozambique Channel: gradient wind, perturbation expansion, and an iterative method. They are tested in a model and applied to satellite altimetry. For an eddy of 25 cm amplitude and 100 km radius, typical of Mozambique Channel rings at 18°S, the error made with geostrophy is 40% for the anticyclones and 20% for the cyclones. Inertia could reach one third of the pressure gradient. Geostrophy underestimates subsurface currents by up to 50 cm s−1, resulting in errors of 30–40%. The iterative method results in errors of <5% for the most part of the structure. The error RMS in velocities based on 8 years of model SSH is in excess of 30 cm s−1 for geostrophy and reduces to about 10 cm s−1 for the gradient wind and iterative methods. The perturbation method is less accurate. Applied to satellite altimetry, the addition of inertia results in a significant increase in velocities for the anticyclones and a decrease for the cyclones. It induces a velocity increase of >50% in Mozambique Channel rings. Geostrophic EKE reaches 1400 cm2 s−2, while it attains 1800 cm2 s−2 when inertia is added. Applied to the Gulf Stream, these methods confirm the hypothesis of Maximenko and Niiler [2006] that centrifugal accelerations should be the main cause for the difference observed between geostrophic and drifter EKE. This methodology should result in a net improvement for operational surface ocean currents.
PY 2014
PD FEB
SO Journal Of Geophysical Research-oceans
SN 0148-0027
PU Amer Geophysical Union
VL 119
IS 2
UT 000336261200026
BP 1054
EP 1067
DI 10.1002/2013JC009528
ID 28617
ER

EF