1. Aquarius/SAC-D Mission Validation Working Group Summary Gary Lagerloef 6 th Science Meeting; Seattle, WA, USA 19-21 July 2010

2. 2 19-21 July 2010 Error Validation & Early Orbit Corrections – Lagerloef 6rh Science Meeting, Seattle, WA, USA Three Phases 1.Pre-Launch 2.In Orbit Checkout (Launch + 45 days) 3.IOC + 6 months

3. 3 19-21 July 2010 Error Validation & Early Orbit Corrections – Lagerloef 6rh Science Meeting, Seattle, WA, USA Validation Working Group Summary -1 Charter: Provide methods to understand and remove systematic SSS retrieval errors and demonstrate that the retrieval accuracy meets mission science requirements. Discussion: 1.Pre-Launch Phase: We reviewed pre-launch simulated error tests; A few WG members expressed interest in working on the evaluation data sets. Mostly this will be done by the Project Science Team and results posted on the Forum. 2.In Orbit Checkout (Launch + 45 days) Phase: We briefly reviewed the preliminary evaluation criteria and concluded that this is also a project team focus. Daily results will be posted during the initial phases of the instrument turn-on sequence and assessment.

4. 4 19-21 July 2010 Error Validation & Early Orbit Corrections – Lagerloef 6rh Science Meeting, Seattle, WA, USA Validation Working Group Summary -2 3.IOC + 6 months Phase: Considerable discussion: 1.Dielectric (Emissivity model): Present model is Meissner-Wentz; will be analyzed and updated during the mission, including new lab measurements by R.Lang. 2.Suggestion to use ECMWF instead of NCEP winds for the early mission phase processing. NCEP is built into present simulator and processing systems, and is intended as a bridge roughness term until the scatterometer is calibrated. Use of an alternate requires changes to the system plus access agreements with ECMWF. It was agreed to delegate the modeling/analysis WG to assess the relative advantage of ECMWF and NOGAPS(US Navy) vs NCEP. 3.Radiative transfer model (RTM): Is the RTM the same as used by NOAA/NAVY for satellite processing? To be investigated. 4.SST corrections: GRSST uncertainties can exceed 1C regionally, generally 0.5C global rms (consistent with Aquarius error budget allocation). A difference map between two GRSST operational SST fields shown in the Modeling/Analysis WG showing large scale systematic differences >1C

5. 5 19-21 July 2010 Error Validation & Early Orbit Corrections – Lagerloef 6rh Science Meeting, Seattle, WA, USA Validation Working Group Summary (3) 3.IOC + 6 months Phase: Considerable discussion: 5.Evaluating error sources in validation data: 1.difference error between a point salinity measurement and the area average over the instantaneous satellite footprint. 2.error due to the temporal or spatial offset between the satellite and in situ samples. 3.difference error between the skin depth (~1-2 cm) salinity and in situ instrument measurement. 4.The in situ sensor calibration error, usually very small. 6.Vertical errors are skewed, many systematic bias problems in historical data. 7.Diurnal SST cycle and day-night SST differences will introduce am/pm orbit bias in retrieved SSS, requires further study for SSS validation. 8.Argo STS profiling upper 5 m to resolve skin effects. Also programmable to surface exactly during a satellite overpass. 9.Suggestion to improve calibration by using the ‘best’ surface data rather than the most data. Establish data quality screen.

6. 6 19-21 July 2010 Error Validation & Early Orbit Corrections – Lagerloef 6rh Science Meeting, Seattle, WA, USA Validation Working Group Summary (4) 3.IOC + 6 months Phase: Considerable discussion: 10.Discussion about approaches to asses global rms error, regional geographically correlated errors and by latitude (temperature) zones.

7. 7 19-21 July 2010 Error Validation & Early Orbit Corrections – Lagerloef 6rh Science Meeting, Seattle, WA, USA