FN Archimer Export Format
PT J
TI An altimetry-based gravest empirical mode south of Africa: 1. Development and validation
BT 
AF SWART, Sebastiaan
   SPEICH, Sabrina
   ANSORGE, Isabelle J.
   LUTJEHARMS, Johann
AS 1:1;2:2;3:1;4:1;
FF 1:;2:;3:;4:PDG-DRO-UMLPO;
C1 Univ Cape Town, Dept Oceanog, ZA-7701 Rondebosch, South Africa.
   Univ Bretagne Occidentale, CNRS, IFREMER, Lab Phys Oceans,UMR 6523, F-29238 Brest, France.
   IFREMER, Univ Bretagne Occidentale, CNRS, Lab Phys Oceans,UMR 6523, F-29238 Brest, France
C2 UNIV CAPE TOWN, SOUTH AFRICA
   UBO, FRANCE
   IFREMER, FRANCE
SI BREST
SE PDG-DOP-DCB-OPS-LPO
   PDG-DRO-UMLPO
IN WOS Ifremer jusqu'en 2018
   copubli-france
   copubli-univ-france
   copubli-int-hors-europe
   copubli-sud
IF 3.303
TC 80
TU Centre national de la recherche scientifique
   Institut de recherche pour le développement
   Institut français de recherche pour l'exploitation de la mer
   Université de Bretagne Occidentale
UR https://archimer.ifremer.fr/doc/00008/11901/8613.pdf
LA English
DT Article
CR MD 166 / BONUS-GOODHOPE
BO Marion Dufresne
AB Hydrographic transects of the Antarctic Circumpolar Current (ACC) south of Africa are projected into baroclinic stream function space parameterized by pressure and dynamic height. This produces a two-dimensional gravest empirical mode (GEM) that captures more than 97% of the total density and temperature variance in the ACC domain. Weekly maps of absolute dynamic topography data, derived from satellite altimetry, are combined with the GEM to obtain a 16 year time series of temperature and salinity fields. The time series of thermohaline fields are compared with independent in situ observations. The residuals decrease sharply below the thermocline and through the entire water column the mean root-mean-square (RMS) error is 0.15 degrees C, 0.02, and 0.02 kg m(-3) for temperature, salinity, and density, respectively. The positions of ACC fronts are followed in time using satellite altimetry data. These locations correspond to both the observed and GEM-based positions. The available temperature and salinity information allow one to calculate the baroclinic zonal velocity field between the surface and 2500 dbar. This is compared with velocity measurements from repeat hydrographic transects at the GoodHope line. The net accumulated transports of the ACC, derived from these different methods are within 1-3 Sv of each other. Similarly, GEM-produced cross-sectional velocities at 300 dbar compare closely to the observed data, with the RMS difference not exceeding 0.03 m s(-1). The continuous time series of thermohaline fields, described here, are further exploited to understand the dynamic nature of the ACC fronts in the region, and which is given by Swart and Speich (2010).
PY 2010
PD MAR
SO Journal Of Geophysical Research-oceans
SN 0148-0227
PU American Geophysical Union
VL 115
IS C03002
UT 000275320000001
BP 1
EP 19
DI 10.1029/2009JC005299
ID 11901
ER

EF