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Argo Update. IGST, St John’s, NL Canada August 7, 2007. Ming Ji, NOAA/NCEP/OPC Steve Piotrowicz, Ocean.US David Behringer NOAA/NCEP/EMC. Active Argo Floats as of 30 June 2007. Countries: 44. Network Growth. Parking and Profiling Depths. Float Survival Rate (all models).
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Argo Update IGST, St John’s, NL Canada August 7, 2007 Ming Ji, NOAA/NCEP/OPC Steve Piotrowicz, Ocean.US David Behringer NOAA/NCEP/EMC
Active Argo Floats as of 30 June 2007 Countries: 44
United States Yearly Deployments (As of 07/07: Total = 2383 Deployed; 1606 Active, U.S. Argo Program = 2101 Deployed; 1517 Active)
Distribution of U.S. Argo Data to the GTS Delays were due to Visual QC
Argo Assimilation at NCEP • GODAS – Climate • HYCOM – Ocean Weather
The Argo array is providing deep temperature profiles for ocean analysis in numbers and coverage previously unavailable. Argo is also providing salinity profiles in numbers that are now practical for use in global analysis.
Current operational GODAS • Temperature profiles from Argo, XBTs, TAO moorings • The depth of the assimilation is 750 meters. Deep assimilation in GODAS-X • Temperature profiles from Argo, XBTs, TAO moorings • The depth of the assimilation is 2200 meters. Assimilating deep Argo temperature profiles has improved the accuracy of the GODAS at mid-depths.
Standard vs. Deep assimilation Independent WOCE CTD section completed in 1988 & 1989 … …and repeated in 2003 & 2005 by PMEL. Shallow assimilation has a strong cold bias of 1-3oC below 750 m. Standard Deep assimilation eliminates the cold bias. Deep
Current operational GODAS • Temperature profiles from Argo, XBTs, TAO moorings • Salinity profiles are 100% synthetic (via TS-relationship) Argo salinity in GODAS-A/S • Temperature profiles from Argo and XBTs only • Salinity profiles are 75% observed (Argo) and 25% synthetic (XBTs) Assimilating Argo salinity profiles has had an unexpected impact on tropical Pacific currents.
Equatorial salinity section in the Pacific (vertical bars show positions of time-series below). Assimilating Argo Salinity Oper GODAS Salinity variability due to correlation with temperature. GODAS-A/S Salinity variability introduced by observations.
In the west, assimilating Argo salinity corrects the bias at the surface and the depth of the undercurrent core and captures the complex structure at 165oE. In the east, assimilating Argo salinity reduces the bias at the surface and sharpens the profile below the thermocline at 110oW. Assimilating Argo Salinity Comparison with independent ADCP currents. ADCP GODASGODAS-A/S
R/V Kaharoa, operated by NIWA/New Zealand 28 meters LOA, 300 tons.