GOCE, Satellite Gravimetry and Antarctic Mass Transports

Rummel, Reiner; Horwath, Martin; Yi, Wu; Albertella, A.; Bösch, Wolfgang; Haagmans, Roger

doi:10.1007/978-94-007-2063-3_21

Cited by 1 publication

(1 citation statement)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While the barotropic flow component is obtained from GRACE, sea surface height anomalies from the satellite altimetry mission TOPEX/Poseidon and its successors can provide information on a large part of the baroclinic variability [ Gille et al , 2001]. Improved retracking algorithms suitable to obtain highly accurate sea level anomalies also near the coasts (see, e.g., for recent technological developments, Gommenginger et al [2011]), in connection with an independently obtained high‐resolution geoid from GOCE [ Rummel et al , 2011] serving as a reference surface for calculating absolute surface geostrophic velocities, calls for a reassessment of previous studies that attempted to monitor the variability of the Antarctic Circumpolar Current from space.…”

Section: Discussionmentioning

confidence: 99%

Short‐term transport variability of the Antarctic Circumpolar Current from satellite gravity observations

Bergmann

Dobslaw

2012

J. Geophys. Res.

View full text Add to dashboard Cite

Ocean bottom pressure gradients deduced from the satellite gravity mission Gravity Recovery and Climate Experiment (GRACE) were previously shown to provide barotropic transport variations of the Antarctic Circumpolar Current (ACC) with up to monthly resolution. Here, bottom pressure distributions from GRACE with monthly (GFZ RL04) and higher temporal resolution (CNES/GRGS with 10 days, ITG‐GRACE2010 with daily resolution) are evaluated over the ACC area. Even on time scales shorter than 10 days, correlations with in situ bottom pressure records frequently exceed 0.6 with positive explained variances, giving evidence that high‐frequency nontidal ocean mass variability is captured by the daily ITG‐GRACE2010 solutions not already included in the applied background models. Bottom pressure is subsequently taken to calculate the barotropic component of the ACC transport variability across Drake Passage. For periods longer than 30 days, transport shows high correlations between 0.4 and 0.5 with several tide gauge records along the coast of Antarctica. Still significant correlations around 0.25 are obtained even for variability with periods shorter than 10 days. Since transport variations are predominantly affected by time‐variable surface winds, GRACE‐based transports are contrasted against an atmospheric index of the Southern Annular Mode (SAM), which represents the Southern Hemispheric wind variability. Correlations between the SAM and GRACE‐based transports are consistently higher than correlations between any of the available sea level records in all frequency bands considered, indicating that GRACE is indeed able to accurately observe a hemispherically consistent pattern of bottom pressure (and hence ACC transport) variability that is otherwise at least partially masked in tide gauge records due to local weather effects, sea ice presence and steric signals.

show abstract

Section: Discussionmentioning

confidence: 99%