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Satellite-Derived Fluxes and Comparisons with NWP Data A. Bentamy; L-H. Ayina; W. Drennan; A. M. Nunez, K. Katsaros, and R. Pinker. Calculation and validation of independent momentum and latent and sensible heat fluxes derived only from satellite data. Satellite Data.
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Satellite-Derived Fluxes and Comparisons with NWP DataA. Bentamy; L-H. Ayina; W. Drennan; A. M. Nunez, K. Katsaros, and R. Pinker Calculation and validation of independent momentum and latent and sensible heat fluxes derived only from satellite data. WGNE-22 Meeting, Boulder 24-27 October 2006
Satellite Data WGNE-22 Meeting, Boulder 24-27 October 2006
Satellite Flux Groups WGNE-22 Meeting, Boulder 24-27 October 2006
Gridded Satellite Flux Characteristics WGNE-22 Meeting, Boulder 24-27 October 2006
Satellite Processing Scheme Data Collection Satellite / Models / In-situ • Satellite Measurements Data Analysis; Method and algorithm for Data Processing; Collocation Calibration / Validation : Wind; Humidity, Air Sea Temperatures Interaction ocean-atmosphere; Parametrization Turbulent Flux Calculations Objective Methods Flux Fields and Error Characteristics Numerical Simulations; Ocean Dynamic Impact and Process Studies WGNE-22 Meeting, Boulder 24-27 October 2006
Latent Heat Flux : 1995 - 2000 WGNE-22 Meeting, Boulder 24-27 October 2006
Sensible Heat Flux : 1995 - 2000 WGNE-22 Meeting, Boulder 24-27 October 2006
Wind Stress : 1995 - 2000 WGNE-22 Meeting, Boulder 24-27 October 2006
Accuracy Issue : Difference Sources • Raw data • Calibration / Validation Procedures • Spatial and Temporal Resolutions • Estimation of basic variables : Winds, Humidity, Sea Surface and Air Temperatures • Analysis Methods • Flux Algorithms • … In-situ / satellite Differences WGNE-22 Meeting, Boulder 24-27 October 2006
Error related to the Retrieval Winds :Wind Stress Climatology from ERS-1/2 and QuikSCAT ERS : 1992 - 2001 QuikSCAT: 1999 - 2005 WGNE-22 Meeting, Boulder 24-27 October 2006
Improvement of the Remotely Sensed Winds • Calibration / Validation • Inverse and Direct models (algorithms) • Parameters : Wind conditions, Sea State, Current, Rain, Stability; • Empirical correction • … Buoy / Satellite Data ERS-1ERS-2QuikSCAT ERA40 WGNE-22 Meeting, Boulder 24-27 October 2006
Error related to the Objective Method Satellite Sampling Scheme • Use of simulated satellite data from buoy measurements or from ECMWF analysis • Temporal Sampling Impact : • <X> : Time - Averaged surface parameter from Hourly Buoy Data • <X’> : Time - Averaged surface parameter from Hourly Buoy Data close to satellite passes • Rms of <X> - <X’> WGNE-22 Meeting, Boulder 24-27 October 2006
NDBC Buoy / Satellite Comparisons WGNE-22 Meeting, Boulder 24-27 October 2006
TAO PIRATA Buoy / Satellite Comparisons WGNE-22 Meeting, Boulder 24-27 October 2006
ODAS Buoy / Satellite Comparisons WGNE-22 Meeting, Boulder 24-27 October 2006
Comparison Buoy /ECMWF / Satellite Winds Tropical Ocean : 10°S – 10°N ERS-1 ERS-2 ECMWF WGNE-22 Meeting, Boulder 24-27 October 2006
Latitudinal Structures over the Atlantic Ocean during : 1995 – 2000 SHF LHF WGNE-22 Meeting, Boulder 24-27 October 2006
Monthly Structures over the Atlantic Ocean during : 1995 – 2000 LHF SHF WGNE-22 Meeting, Boulder 24-27 October 2006
Three Sensitivity Experiments Reference = EXP1 TForced with daily fluxes of 1994 to 1999 derived from ECMWF analysis. - SST - relaxed toward the climatology of Reynolds & Smith 1994 (RS94) - SSS - relaxed toward Levitus (1994) b - Spin-up forced during 10 years with daily mean ECMWF (1994 –1996) Second = EXP2 TForced substituting ECMWF latent heat flux by daily satellite estimates during the period 1996-1998. His initial state correspond to the EXP1 state at December 31, 1995. Third = EXP3 TForced substituting the daily satellite stress wind and latent heat flux to ECMWF estimates during the period 1996-1998. His initial state is same than EXP2. WGNE-22 Meeting, Boulder 24-27 October 2006
Accuracy Issue : Forcing OGCM EXP1 X – SST RS94 and Y— Exps’ SST RS94 — Reynolds and Smith (1994) EXP2 EXP3 –— EXP1 –— EXP2 –— EXP3 … RS94 WGNE-22 Meeting, Boulder 24-27 October 2006 EXP1
Summary / Perspectives / Questions(1) • 15 years of satellite fluxes are available • Resolutions • Spatial : 1°; 0.5°; 0.25°; 0.125° • Temporal : 6h; 12h; daily; Weekly; monthly, Climatology • Satellite and buoy flux estimates compare well • Satellite fluxes exhibt similar features • Satellite and model fluxes • Similar large patterns • Significant difference in magnitude WGNE-22 Meeting, Boulder 24-27 October 2006
Summary / Perspectives / Questions(2) • Reprocessing of Surface Wind since 1992 (earlier?) • Re-analysis of satellite fluxes since 1992(earlier?) • Including Radiative Fluxes • Impact Analysis • MERCATOR Proposal : 50 year ocean circulation re-analysis • MERSEA project • Calculation of Blended products in near real and delayed time • Numerical Simulations using Blended data (Circulation and wave models) • Characterization of NWP and Satellite differences at global and regional scales • Archiving, Distribution, and facilities • Using New data : exp. METOP / ASCAT WGNE-22 Meeting, Boulder 24-27 October 2006
Summary / Perspectives / Questions(3) How can we meet the perspectives • For operatonal Oceanography • E.U. projects : MERSEA • GMES : ? • Seaflux • Others? WGNE-22 Meeting, Boulder 24-27 October 2006