INVESTIGADORES
FERRARI Ramiro
artículos
Título:
Volume transport of the Antarctic Circumpolar Current: Production and validation of a 20 year long time series obtained from in situ and satellite observations
Autor/es:
ZOÉ KOENIG; CHRISTINE PROVOST; RAMIRO FERRARI; NATHALIE SENNÉCHAEL; MARIE-HÉLÈNE RIO
Revista:
JOURNAL OF GEOPHYSICAL RESEARCH
Editorial:
AMER GEOPHYSICAL UNION
Referencias:
Año: 2014 p. 5407 - 5433
ISSN:
0148-0227
Resumen:
A 20 year long volume transport time series of the Antarctic Circumpolar
Current across the Drake Passage is estimated from the combination of
information from in situ current meter data (2006?2009) and satellite
altimetry data (1992?2012). A new method for transport estimates had to
be designed. It accounts for the dependence of the vertical velocity
structure on surface velocity and latitude. Yet unpublished velocity
profile time series from Acoustic Doppler Current Profilers are used to
provide accurate vertical structure estimates in the upper 350 m. The
mean cross-track surface geostrophic velocities are estimated using an
iterative error/correction scheme to the mean velocities deduced from
two recent mean dynamic topographies. The internal consistency and the
robustness of the method are carefully assessed. Comparisons with
independent data demonstrate the accuracy of the method. The full-depth
volume transport has a mean of 141 Sv (standard error of the mean 2.7
Sv), a standard deviation (std) of 13 Sv, and a range of 110 Sv. Yearly
means vary from 133.6 Sv in 2011 to 150 Sv in 1993 and standard
deviations from 8.8 Sv in 2009 to 17.9 Sv in 1995. The canonical ISOS
values (mean 133.8 Sv, std 11.2 Sv) obtained from a year-long record in
1979 are very similar to those found here for year 2011 (133.6 Sv and 12
Sv). Full-depth transports and transports over 3000 m barely differ as
in that particular region of Drake Passage the deep recirculations in
two semiclosed basins have a close to zero net transport.