Antarctic circumpolar current transport variability during 2003–05 from GRACE
Gravity Recovery and Climate Experiment (GRACE) gravity data spanning January 2003–November 2005 are used as proxies for ocean bottom pressure (BP) averaged over 1 month, spherical Gaussian caps 500 km in radius, and along paths bracketing the Antarctic Circumpolar Current’s various fronts. The GRAC...
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ftnasajpl:oai:trs.jpl.nasa.gov:2014/40371 2023-05-15T13:31:32+02:00 Antarctic circumpolar current transport variability during 2003–05 from GRACE Zlotnicki, Victor Wahr, John Fukumori, Ichiro Song, Yuhe T. 2007-08-16T21:13:55Z 1314286 bytes application/pdf http://hdl.handle.net/2014/40371 en_US eng American Meteorological Society Journal of Physical Oceanography, February 2007 (Vol. 37, No. 2, 230-244) 06-2279 http://hdl.handle.net/2014/40371 Gravity Recovery and Climate Experiment (GRACE) Antarctic currents Article 2007 ftnasajpl 2021-12-23T13:12:19Z Gravity Recovery and Climate Experiment (GRACE) gravity data spanning January 2003–November 2005 are used as proxies for ocean bottom pressure (BP) averaged over 1 month, spherical Gaussian caps 500 km in radius, and along paths bracketing the Antarctic Circumpolar Current’s various fronts. The GRACE BP signals are compared with those derived from the Estimating the Circulation and Climate of the Ocean (ECCO) ocean modeling–assimilation system, and to a non-Boussinesq version of the Regional Ocean Model System (ROMS). The discrepancy found between GRACE and the models is 1.7 cm H2O (1 cm H2O ~ 1 hPa), slightly lower than the 1.9 cmH2O estimated by the authors independently from propagation of GRACE errors. The northern signals are weak and uncorrelated among basins. The southern signals are strong, with a common seasonality. The seasonal cycle GRACE data observed in the Pacific and Indian Ocean sectors of the ACC are consistent, with annual and semiannual amplitudes of 3.6 and 0.6 cmH2O (1.1 and 0.6 cm H2O with ECCO), the average over the full southern path peaks (stronger ACC) in the southern winter, on days of year 197 and 97 for the annual and semiannual components, respectively; the Atlantic Ocean annual peak is 20 days earlier. An approximate conversion factor of 3.1 Sv (Sv equiv 106 m3 sˉ¹) of barotropic transport variability per cm H2O of BP change is estimated. Wind stress data time series from the Quick Scatterometer (QuikSCAT), averaged monthly, zonally, and over the latitude band 40°– 65°S, are also constructed and subsampled at the same months as with the GRACE data. The annual and semiannual harmonics of the wind stress peak on days 198 and 82, respectively. A decreasing trend over the 3 yr is observed in the three data types. NASA/JPL Article in Journal/Newspaper Antarc* Antarctic JPL Technical Report Server Antarctic Indian Pacific The Antarctic |
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Open Polar |
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JPL Technical Report Server |
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ftnasajpl |
language |
English |
topic |
Gravity Recovery and Climate Experiment (GRACE) Antarctic currents |
spellingShingle |
Gravity Recovery and Climate Experiment (GRACE) Antarctic currents Zlotnicki, Victor Wahr, John Fukumori, Ichiro Song, Yuhe T. Antarctic circumpolar current transport variability during 2003–05 from GRACE |
topic_facet |
Gravity Recovery and Climate Experiment (GRACE) Antarctic currents |
description |
Gravity Recovery and Climate Experiment (GRACE) gravity data spanning January 2003–November 2005 are used as proxies for ocean bottom pressure (BP) averaged over 1 month, spherical Gaussian caps 500 km in radius, and along paths bracketing the Antarctic Circumpolar Current’s various fronts. The GRACE BP signals are compared with those derived from the Estimating the Circulation and Climate of the Ocean (ECCO) ocean modeling–assimilation system, and to a non-Boussinesq version of the Regional Ocean Model System (ROMS). The discrepancy found between GRACE and the models is 1.7 cm H2O (1 cm H2O ~ 1 hPa), slightly lower than the 1.9 cmH2O estimated by the authors independently from propagation of GRACE errors. The northern signals are weak and uncorrelated among basins. The southern signals are strong, with a common seasonality. The seasonal cycle GRACE data observed in the Pacific and Indian Ocean sectors of the ACC are consistent, with annual and semiannual amplitudes of 3.6 and 0.6 cmH2O (1.1 and 0.6 cm H2O with ECCO), the average over the full southern path peaks (stronger ACC) in the southern winter, on days of year 197 and 97 for the annual and semiannual components, respectively; the Atlantic Ocean annual peak is 20 days earlier. An approximate conversion factor of 3.1 Sv (Sv equiv 106 m3 sˉ¹) of barotropic transport variability per cm H2O of BP change is estimated. Wind stress data time series from the Quick Scatterometer (QuikSCAT), averaged monthly, zonally, and over the latitude band 40°– 65°S, are also constructed and subsampled at the same months as with the GRACE data. The annual and semiannual harmonics of the wind stress peak on days 198 and 82, respectively. A decreasing trend over the 3 yr is observed in the three data types. NASA/JPL |
format |
Article in Journal/Newspaper |
author |
Zlotnicki, Victor Wahr, John Fukumori, Ichiro Song, Yuhe T. |
author_facet |
Zlotnicki, Victor Wahr, John Fukumori, Ichiro Song, Yuhe T. |
author_sort |
Zlotnicki, Victor |
title |
Antarctic circumpolar current transport variability during 2003–05 from GRACE |
title_short |
Antarctic circumpolar current transport variability during 2003–05 from GRACE |
title_full |
Antarctic circumpolar current transport variability during 2003–05 from GRACE |
title_fullStr |
Antarctic circumpolar current transport variability during 2003–05 from GRACE |
title_full_unstemmed |
Antarctic circumpolar current transport variability during 2003–05 from GRACE |
title_sort |
antarctic circumpolar current transport variability during 2003–05 from grace |
publisher |
American Meteorological Society |
publishDate |
2007 |
url |
http://hdl.handle.net/2014/40371 |
geographic |
Antarctic Indian Pacific The Antarctic |
geographic_facet |
Antarctic Indian Pacific The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
Journal of Physical Oceanography, February 2007 (Vol. 37, No. 2, 230-244) 06-2279 http://hdl.handle.net/2014/40371 |
_version_ |
1766018637498417152 |