Satellite Altimetry in the Gulf of Mexico Techniques Tools and Theory Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Today s SSH SST Overlay Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Yesterday s Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Outline of Talk Introduction to Gulf of Mexico Oceanography Techniques Overview of CCAR near real time altimeter data system Recent update and validation of system Sample near real time products and applications Tools On line forms for plotting GOM data Online SSH SST Overlay form Loop Current Toolbox Theory Loop Current Eddy Shedding and Upstream Influences Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Oceanographic Overview The Gulf of Mexico GOM is an oceanographic region where the general circulation is dominated by mesoscale circulation Loop Current Loop Current eddies anticyclones highs cyclones lows eddy pairs Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 JHUAPL 3 day composite SST 2 22 2003 Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Schematic of Altimeter System Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Schematic of Corrections Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 CCAR Mesoscale SSH Map 2 22 2003 Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 SST SSH Overlay October 22 2003 Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Altimetry Blended SSH Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 GOM SSH Map 10 22 2003 Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 GOM SSH Anomaly 10 22 2003 Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Original CCAR Near Real time Altimeter System Quick look processing designed to retain and map mesoscale variability Went online in early 1996 Used NOAA Laboratory for Satellite Altimetry ERS and Geosat Follow on near real time altimeter data products Enhanced NOAA corrections Delft Institute for Earth Oriented Space Research orbits Used near real time TOPEX RGDRs Processed by the Naval Oceanographic Office Altimeter Data Fusion Center JPL Earth Orbiter Systems Group GPS orbit CCAR system was designed so that quick look products are processed and posted by 12 00 p m MST Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 CCAR Quick look mesoscale analysis All altimeter data are referenced to an independent gridded mean sea surface The data are treated as non repeating ground tracks and are referenced directly to the mean sea surface non collinear processing Saves a significant amount of computational effort during near real time processing Along track loess filtering is used to remove residual orbit and environmental correction errors The loess filtering removes a running least squares fit of a tilt and bias line within a sliding window from the along track data The window width is approximately 15 degrees or 200 seconds along track The detrended data are objectively mapped to a 1 4 grid In the Gulf a model mean or mean dynamic height is added to the anomaly to estimate the total sea surface height Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Current CCAR Near Real time Altimeter System Updated collinear processing and new reference mean sea surface Went online in summer 2003 Uses NOAA Laboratory for Satellite Altimetry ERS and Geosat Follow on near real time altimeter data products Only North Atlantic and GOM ERS 2 data since tape recorder failure NRT ERS 2 processing will be suspended soon Uses near TOPEX and Jason 1 RGDRs Stack file processing thanks to Eric Leuliette and Gerard Kruizinga JPL Earth Orbiter Systems Group GPS orbits and real time data Envisat data will be added this summer Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Updating of the Mean Reference Surface The original system used the Ohio State University MSS 1995 OSUMSS95 or Rapp Mean as the mean reference surface 1 16 spatial resolution Based on one year means from T P 10 day repeat ERS 1 35 day repeat and Geosat 17 day repeat and one 168 day repeat cycle from the ERS 1 Geodetic Mission Phase Yi 1995 The updated system uses the Goddard Spaceflight Center MSS 00 1 GSFC00 1 MSS or the Goddard Mean 1 30 spatial resolution Based on Geosat Geodetic ERM data multi years of ERS 1 2 35 day repeat data both cycles of ERS 1 168 day repeat data and 6 years of T P data Wang 2001 in JGR Oceans Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Gulf of Mexico Goddard Mean Sea Surface GSFC00 1 MSS Wang 2001 JGR Oceans Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Goddard Mean minus Rapp Mean Difference of Gridded Fields T P and ERS 35 day repeat along track differences Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 1993 1999 Mean Anomalies Rapp Mean Anomaly Goddard Mean Anomaly Centimeters Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 RMS Difference 1993 1999 Mean Anomaly Colorado Center for Astrodynamics Research University of Colorado at Boulder Remote Sensing Seminar 14 April 02 Online Data Access Tools Gulf of Mexico Interactive Online Data Forms Gulf of Mexico Near Real Time Data Viewer Gulf of Mexico Near Real Time Geostrophic Velocity Vector Viewer Gulf of Mexico Along Track Data Host Gulf of Mexico Along Track Visualization One Day Gulf of Mexico Along Track Visualization Multiple Day Colorado Center for Astrodynamics Research University of