Using Ocean Bottom Pressure from the Gravity Recovery and Climate Experiment (GRACE) to Estimate Transport Variability in the Southern Indian Ocean
Previous studies have suggested that ocean bottom pressure (OBP) from the Gravity Recovery and Climate Experiment (GRACE) can be used to measure the depth-averaged, or barotropic, transport variability of the Antarctic Circumpolar Current (ACC). Here, we use GRACE OBP observations to calculate trans...
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ftunisfloridatam:oai:digitalcommons.usf.edu:msc_facpub-2413 2023-05-15T14:04:11+02:00 Using Ocean Bottom Pressure from the Gravity Recovery and Climate Experiment (GRACE) to Estimate Transport Variability in the Southern Indian Ocean Makowski, Jessica K. Chambers, Don P. Bonin, Jennifer A. 2015-01-01T08:00:00Z application/pdf https://digitalcommons.usf.edu/msc_facpub/1405 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2413&context=msc_facpub unknown Digital Commons @ University of South Florida https://digitalcommons.usf.edu/msc_facpub/1405 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2413&context=msc_facpub default Marine Science Faculty Publications Antarctic circumpolar current Southern Ocean GRACE ocean bottom pressure Life Sciences article 2015 ftunisfloridatam 2022-01-20T18:39:16Z Previous studies have suggested that ocean bottom pressure (OBP) from the Gravity Recovery and Climate Experiment (GRACE) can be used to measure the depth-averaged, or barotropic, transport variability of the Antarctic Circumpolar Current (ACC). Here, we use GRACE OBP observations to calculate transport variability in a region of the southern Indian Ocean encompassing the major fronts of the ACC. We use a statistical analysis of a simulated GRACE-like data set to determine the uncertainty of the estimated transport for the 2003.0–2013.0 time period. We find that when the transport is averaged over 60° of longitude, the uncertainty (one standard error) is close to 1 Sv (1 Sv = 106 m3 s−1) for low-pass filtered transport, which is significantly smaller than the signal and lower than previous studies have found. The interannual variability is correlated with the Southern Annual mode (SAM) (0.61), but more highly correlated with circumpolar zonally averaged winds between 45°S and 65°S (0.88). GRACE transport reflects significant changes in transport between 2007 and 2009 that is observed in the zonal wind variations but not in the SAM index. We also find a statistically significant trend in transport (−1.0 ± 0.4 Sv yr−1, 90% confidence) that is correlated with a local deceleration in zonal winds related to an asymmetry in the SAM on multidecadal periods. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean Digital Commons University of South Florida (USF) Antarctic Southern Ocean The Antarctic Indian |
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Open Polar |
collection |
Digital Commons University of South Florida (USF) |
op_collection_id |
ftunisfloridatam |
language |
unknown |
topic |
Antarctic circumpolar current Southern Ocean GRACE ocean bottom pressure Life Sciences |
spellingShingle |
Antarctic circumpolar current Southern Ocean GRACE ocean bottom pressure Life Sciences Makowski, Jessica K. Chambers, Don P. Bonin, Jennifer A. Using Ocean Bottom Pressure from the Gravity Recovery and Climate Experiment (GRACE) to Estimate Transport Variability in the Southern Indian Ocean |
topic_facet |
Antarctic circumpolar current Southern Ocean GRACE ocean bottom pressure Life Sciences |
description |
Previous studies have suggested that ocean bottom pressure (OBP) from the Gravity Recovery and Climate Experiment (GRACE) can be used to measure the depth-averaged, or barotropic, transport variability of the Antarctic Circumpolar Current (ACC). Here, we use GRACE OBP observations to calculate transport variability in a region of the southern Indian Ocean encompassing the major fronts of the ACC. We use a statistical analysis of a simulated GRACE-like data set to determine the uncertainty of the estimated transport for the 2003.0–2013.0 time period. We find that when the transport is averaged over 60° of longitude, the uncertainty (one standard error) is close to 1 Sv (1 Sv = 106 m3 s−1) for low-pass filtered transport, which is significantly smaller than the signal and lower than previous studies have found. The interannual variability is correlated with the Southern Annual mode (SAM) (0.61), but more highly correlated with circumpolar zonally averaged winds between 45°S and 65°S (0.88). GRACE transport reflects significant changes in transport between 2007 and 2009 that is observed in the zonal wind variations but not in the SAM index. We also find a statistically significant trend in transport (−1.0 ± 0.4 Sv yr−1, 90% confidence) that is correlated with a local deceleration in zonal winds related to an asymmetry in the SAM on multidecadal periods. |
format |
Article in Journal/Newspaper |
author |
Makowski, Jessica K. Chambers, Don P. Bonin, Jennifer A. |
author_facet |
Makowski, Jessica K. Chambers, Don P. Bonin, Jennifer A. |
author_sort |
Makowski, Jessica K. |
title |
Using Ocean Bottom Pressure from the Gravity Recovery and Climate Experiment (GRACE) to Estimate Transport Variability in the Southern Indian Ocean |
title_short |
Using Ocean Bottom Pressure from the Gravity Recovery and Climate Experiment (GRACE) to Estimate Transport Variability in the Southern Indian Ocean |
title_full |
Using Ocean Bottom Pressure from the Gravity Recovery and Climate Experiment (GRACE) to Estimate Transport Variability in the Southern Indian Ocean |
title_fullStr |
Using Ocean Bottom Pressure from the Gravity Recovery and Climate Experiment (GRACE) to Estimate Transport Variability in the Southern Indian Ocean |
title_full_unstemmed |
Using Ocean Bottom Pressure from the Gravity Recovery and Climate Experiment (GRACE) to Estimate Transport Variability in the Southern Indian Ocean |
title_sort |
using ocean bottom pressure from the gravity recovery and climate experiment (grace) to estimate transport variability in the southern indian ocean |
publisher |
Digital Commons @ University of South Florida |
publishDate |
2015 |
url |
https://digitalcommons.usf.edu/msc_facpub/1405 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2413&context=msc_facpub |
geographic |
Antarctic Southern Ocean The Antarctic Indian |
geographic_facet |
Antarctic Southern Ocean The Antarctic Indian |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_source |
Marine Science Faculty Publications |
op_relation |
https://digitalcommons.usf.edu/msc_facpub/1405 https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=2413&context=msc_facpub |
op_rights |
default |
_version_ |
1766275202356871168 |