NOAA Ocean Surface Wind Vectors from Wind Sat

NOAA Ocean Surface Wind Vectors from Wind. Sat Polarimetric Measurements Zorana Jelenak, Tim Mavor, Laurence Connor, Nai-Yu Wang and Paul S. Chang NOAA/NESDIS/ORA Mike Bettenhausen and Peter Gaiser NRL February 2005 Ocean Wind Vector Workshop, Miami, FL

Wind. Sat-Mission Successfully launched on January 6 th 2003 with the objectives to: l Demonstrate the capability of Polarimetric Microwave Radiometry to measure the Ocean Surface Wind Vector from Space l Show potential to measure other EDR’s: SST, Water Vapor, Cloud liquid water, rain rate, sea ice and snow cover l February 2005 OVW NASA/NOAA Workshop, Miami, FL

Talk Outline l What did we know? l What did we learn? l What is it that we still don’t know? February 2005 OVW NASA/NOAA Workshop, Miami, FL

Ocean Brightness Temperatures l Tb’s measured by satellite radiometer consists of: – Signal that is emitted from the ocean surface and travels upwards – Upward traveling atmospheric radiation – Downward traveling atmospheric and cold space radiation that is scattered back from the ocean surface February 2005 OVW NASA/NOAA Workshop, Miami, FL

Theoretical Model February 2005 OVW NASA/NOAA Workshop, Miami, FL

Wind. Sat Data on PODAAC l SDR’s Ver. 1. 6. 1 l NOAA EDR’s. Based on 1. 5. 1 SDR’s – NESDIS_0 Algorithm version l NOAA EDR’s Based on 1. 6. 1 SDR’s – NESDIS_1 Algorithm version Wind Speed Algorithm l SST Algorithm l QC flag l February 2005 OVW NASA/NOAA Workshop, Miami, FL

CLW Retrievals 18. 7, 28. 8 and 37 GHz NOAA Wind. Sat Wind Vector Retrieval Algorithm – Ver 0 Wind Direction Retrievals WV Retrievals 18. 7, 23. 8 and 37 GHz Wind Speed Retrievals 10. 7, 18. 7, 23. 8 and 37 GHz SST Retrievals 10. 7, 18. 7 and 37 GHz 3 rd and 4 th Stokes Ambiguity Removal • 4 possible solution • GDAS initialization • Median filter • 3 passes 10. 7 GHz February 2005 OVW NASA/NOAA Workshop, Miami, FL

CLW Retrievals 18. 7, 28. 8 and 37 GHz NOAA Wind. Sat Wind Vector Retrieval Algorithm – Ver 1 Wind Direction Retrievals WV Retrievals 18. 7, 23. 8 and 37 GHz Wind Speed Retrievals 10. 7, 18. 7, 23. 8 and 37 GHz SST Retrievals 10. 7, 18. 7 and 37 GHz 3 rd and 4 th Stokes Ambiguity Removal • 4 possible solution • GDAS initialization • Median filter • 3 passes 10. 7 GHz February 2005 OVW NASA/NOAA Workshop, Miami, FL

Wind. Sat 1. 5. 1 EDR’s Data from Sep, 2003 to February, 2004 l Retrievals performed over: – Ocean flagged points – Only fore measurements l Retrievals flagged for: – Out of bounds Tb’s – Out of bounds eia – Geographical regions – Rain and ice contamination – High values of wind speed, cloud liquid water and water vapor l February 2005 OVW NASA/NOAA Workshop, Miami, FL

EDR Validation Data Set WS-GDAS-QSCAT-SSMI (Sep, 2003 – Feb, 2004) l Matchup criteria: – – l 35 min between WS-SSMI and 1 h WS-QSCAT 1 h WS-GDAS 1 h QSCAT-GDAS Validation criteria: – Wspd, based on GDAS wspd – Wind direction based on GDAS wind direction. Two sets of data: l All points that satisfied matchup criteria l Edited set: (WS-GDAS)<90 – WV and CLW bins based on SSMI retrievals – SST bins based on GDAS surface SST February 2005 OVW NASA/NOAA Workshop, Miami, FL

February 2005 OVW NASA/NOAA Workshop, Miami, FL

VER 0 February 2005 VER 1 OVW NASA/NOAA Workshop, Miami, FL

Wind Speed Retrievals VER 0 Regression based algorithm -Tbv, h 10, Tbv, h 18, Tbv 23, Tbv 37 -tpw dependent -dc dependent February 2005 VER 1 Regression based algorithm -Tbv 10, Tbv, h 18, Tbv 23, Tbv, h 37 -tpw dependent -dc dependent OVW NASA/NOAA Workshop, Miami, FL

Wind Speed Algorithm Performances VER 0 Across Swath VER 0 Versus CLW VER 1 VER 0 Versus SST Versus TPW mean February 2005 OVW NASA/NOAA Workshop, Miami, FL VER 1

Wind Direction Validation VER 0 February 2005 VER 1 OVW NASA/NOAA Workshop, Miami, FL

Algorithm Performance - Wind Direction Across Swath Versus SST Versus CLW Versus TPW February 2005 OVW NASA/NOAA Workshop, Miami, FL

Wind Speed and Directional Histograms VER 1 February 2005 OVW NASA/NOAA Workshop, Miami, FL

February 2005 OVW NASA/NOAA Workshop, Miami, FL

February 2005 OVW NASA/NOAA Workshop, Miami, FL

Wind. Sat Quik. Scat November 5, 2003 (rev 04529) February 2005 OVW NASA/NOAA Workshop, Miami, FL

Wind. Sat February 2005 Quik. SCAT OVW NASA/NOAA Workshop, Miami, FL

Conclusions l Wind. Sat wind vector retrieval algorithm has been developed and six months of Windsat EDR’s has been released – EDR’s based on 1. 6. 1 SDR’s will be released in March l A*Tbv-Tbh relationship developed – Almost independent of atmospheric parameters – When used in retrievals instrument skill improves l Initial cal/val done – Initial validation results show that wind speed rms error <2 m/s for wind speed between [3 -20]m/s – Wind Directional error <25 for wind speeds [5 -20]m/s for selected solutions – Large retrieval errors are associated with large values of cloud liquid water and water vapor in the atmosphere February 2005 OVW NASA/NOAA Workshop, Miami, FL

l Wind. Sat Wind Vector Imagery available – http: //manati. orbit. nesdis. noaa. gov/windsat l PODAAC Wind. Sat Web page – http: //podaac. jpl. nasa. gov/windsat February 2005 OVW NASA/NOAA Workshop, Miami, FL