Mean dynamic topography of the Gulf of Mexico with application to satellite altimetry

Abstract

Abstract A new calculation of the mean dynamic sea surface topography for the Gulf of Mexico is presented. All available hydrographic, STD, and XBT data from the national archive and other sources are combined to calculate the mean dynamic height of the basin at 25‐km horizontal spatial resolution, using 1000 db as the reference level. In all, over 26,000 stations were considered, approximately 15% of which were rejected for geographic, oceanographic, or instrumental reasons. Most of the observations were taken between 1969 and 1973, were equally spread over all seasons except winter, and were mostly in the eastern Gulf. Standard error of the mean surface is estimated at less than ±2 dyn‐cm (dynamic centimeters). The mean dynamic topography is dominated by the 150‐dyn‐cm high associated with the Gulf Loop Current in the eastern basin, and by a cyclone/anticyclone pair in the western basin. Standard deviation about the mean relative to 450 db accounts for 75% of the 1000‐db variation and shows that more th...