Altimetry-derived surface geostrophic currents in the Gulf of Mexico
Satellite altimetry data (1993-2017) are used to describe the the Gulf of Mexico (GoM) Loop Current (LC) system. We use the
delayed-time, merged/gridded 1/4° sea surface height (SSH) anomalies produced by AVISO+ (www.aviso.altimetry.fr/) and
obtained from the E.U. Copernicus Marine Service Information (http://marine.copernicus.eu/). A mean dynamic height of
mdt_cnes_cls2013 is added to the sea level anomaly data, and annual cycles are removed to reduce the steric height effect.
Geostrophic currents are computed from the gradient of the SSH. A quantitative assesment using the satellite-tracked drifter
trajectory observations in the estern Gulf of Mexico show that the altimetry-derived current products performs better than the data
assimilative numerical models in providing essential surface current information [Liu et al., 2014]. The altimetry product was used in a series of analyses of the Gulf of Mexico Loop Current
patterns by the USF Ocean Circulation Group [Alvera-Azcárate
et al., 2009; Liu et al., 2011; Liu et al., 2016a] and the West Florida Shelf offshore forcing
index [Liu et al., 2016b]. Recently, the altimetry data were used to study the West Florida Shelf's
role of an anchor that affects the LC pentration into the GoM [Weisberg and Liu, 2017].
Characteristic patterns of the GOM LC patterns are summerized in recent analysis using the Self-Organizing
Map. Snapshots of sea surface height and surface geostrophic currents are shown in movies below:
The analyses and data are research products under development. No warranty is made, expressed or implied, regarding accuracy, or regarding the suitability for any particular application. All rights reserved University of
South Florida, Ocean Circulation Group. Copyright University of South Florida 2017.