GOES-R AWG 2 nd Validation Workshop 9-10 January 2014, College Park, MD GOES-R and JPSS SST Monitoring System Sasha Ignatov, Prasanjit Dash, Xingming Liang, Feng Xu, Yury Kihai, Xinjia Zhou With support from John Sapper, John Stroup, Boris Petrenko, Marouan Boauli 9 January 2014GOES-R SST Validation1

SQUAM - SST Quality Monitor Monitor SST Products (L2, L3, L4) for Self- and Cross- Consistency; Validate against in situ SSTs ( i Quam) i Quam - In situ Quality Monitor QC in situ SSTs, Monitor on Web, Distribute to users Input to SQUAM MICROS - Monitoring IR Clear-sky Radiances over Oceans for SST Monitor Clear-sky ocean radiances for Self- and Cross- Consistency; Validate against CRTM simulations NOAA JPSS and GOES-R Cal/Val Tools 9 January 20142GOES-R SST Validation SST Community Resources, Support JPSS and GOES-R

3 Principles of NOAA SST Monitoring 9 January 2014GOES-R SST Validation Monitor automatically, in Near-Real Time, Globally, Online -Satellite SSTs against reference SST -Satellite sensor radiances associated with SST -Reference SSTs (in situ, L4) Monitor GOES-R and JPSS SST products in context of other community SST products Monitor deviations from a reference state (expected to be centered at zero, and have a narrow Gaussian distribution) Supplement heritage VAL against in situ SST (sparse, geographically biased, suboptimal quality, not available in NRT) with global consistency checks against another reference, L4 analysis fields (global coverage, large statistics, more uniform data quality, available in NRT)

SST Monitoring in SST Quality Monitor (SQUAM) 9 January 20144GOES-R SST Validation Das, et al: SST Quality Monitor. JTECH, 2010.

DAY: VIIRS L2 minus OSTIA L4 28 December 2013 Deviation from Reference SST is flat & close to 0 Residual Cloud/Aerosol leakages seen as cold spots Warm spots show areas with diurnal warming during daytime 9 January 2014GOES-R SST Validation5

DAY: VIIRS L2 minus in situ SST 28 December 2013 Much fewer match-ups with in situ data than with L4 Validation statistics may not be globally representative Daily validation statistics may not be accurate and stable 9 January 2014GOES-R SST Validation6

DAY: VIIRS L2 minus OSTIA L4 28 December 2013 Shape close to Gaussian but skewed positively due to diurnal warming Domain & Performance Stats close to expected 9 January 2014GOES-R SST Validation7

DAY: VIIRS L2 minus in situ SST 28 December 2013 Shape close to Gaussian Domain & Performance Stats better than spec 9 January 2014GOES-R SST Validation8

DAY 28 December 2013 – Summary NOBSMin/ MaxMean/ STDMed/ RSDSkew/ Kurt 117,600, / / / / +7.9 ΔT = “VIIRS minus OSTIA” SST 9 January 2014 NOBSMin/ MaxMean/ STDMed/ RSDSkew/ Kurt 1, / / / / +2.8 ΔT = “VIIRS minus in situ” SST 9GOES-R SST Validation

DAY STD DEV wrt. In situ SST Outliers come from satellite and in situ data IDPS shows larger STD although improved recently 9 January 2014GOES-R SST Validation10 Daily val against in situ SST is noisy due to small match-up sample & lack of global coverage IDPS SST improved recently but has been out of family for the full 2 years of monitoring

DAY STD DEV wrt. Reynolds L4 9 January 2014GOES-R SST Validation11 IDPS shows much larger STD IDPS SST has been out of family but improved in mid Still significantly deviates from family, but less than earlier in the mission

DAY STD DEV wrt. OSTIA L4 9 January 2014GOES-R SST Validation12 IDPS shows much larger STD Comparison with OSTIA SST suggest the same qualitative observations as against Reynolds and in situ, although quantitatively, comparison statistics may differ

VIIRS, MODIS, and AVHRR Radiance Monitoring in MICROS 9 January Liang, Ignatov: Monitoring IR Clear-Sky Radiances over Oceans for SST. JTECH, GOES-R SST Validation

Model minus Observation (“M-O”) Biases -M (Model) = Community Radiative Transfer Model (CRTM) simulated TOA Brightness Temperatures (w/ Reynolds SST, GFS profiles as input) -O (Observation) = Clear-Sky sensor (AVHRR, MODIS, VIIRS) BTs Double Differences (“DD”) for Cross-Platform Consistency -“M” used as a “Transfer Standard” -DDs cancel out/minimize effect of systematic errors & instabilities in BTs arising from e.g. -Errors/Instabilities in Reynolds SST & GFS -Missing aerosol -Possible systemic biases in CRTM -Updates to ACSPO algorithm M-O Biases and Double Differences (“DD”) 9 January GOES-R SST Validation

All AVHRRs (except N16 and Metop-B), MODISs, and VIIRS are now consistent to within ±0.1K VIIRS Cal change 7 Mar 2012 reset by +0.14K – now better in family Before 13 Sep 2012: Terra & Aqua/MODIS were biased by -0.6K (suboptimal CRTM coeffs in v2.02) Both are back in family now, after CRTM V2.1 implemented on 13 Sep 2012 Metop–B out of family by ~+0.3 K (likely due to suboptimal CRTM coefficients in CRTM V2.1) N16: unstable and out of family CRTM V2.1 implemented Metop-B: out of family Double Differences in IR11 (VIIRS M15) 9 January VIIRS recalibration GOES-R SST Validation

All AVHRRs, MODISs and NPP/VIIRS SSTs are consistent to within ±0.1K As a result of VIIRS Cal Change on 7 Mar 2012, VIIRS SST went out of family Was brought back in family when new SST coefficients implemented 3 May 2012 CRTM update resulted regression SSTs more noise, and the new coefficients have been implemented since Dec More data is needed to understand their performance N16: unstable and out of family VIIRS recalibrationCRTM V2.1 implemented Double Differences in SST 9 January New Reg. Coeff. used GOES-R SST Validation

In situ SST QC & Monitoring in iQuam 9 January Xu, Ignatov: In situ SST Quality Monitor. JTECH, GOES-R SST Validation

9 January 2014GOES-R SST Validation18 In situ Quality Monitor (iQuam) performs the following functions  QC: Accurate/flexible QC of in situ SSTs, consistent with wider Meteorological and Oceanographic communities  Monitoring: Report online statistical summaries of in situ minus reference L4 SST (stratified by ships, drifters, tropical & coastal moored, ARGO floats; and individual platforms)  Data Serving: Serve QCed in situ SST data online for SST community Objectives of in situ SST Quality Monitor

9 January 2014GOES-R SST Validation19 Quality Control – Consistent with UK MO CategoryCheckType of error handledPhysical basis PreprocessingDuplicate Removal Duplicates arise from multiple transmission or data set merging Identical space/time/ID PlausibilityPlausibility checks Unreasonable field valuesRange of single fields & Relationships among them Internal consistency TrackingPoints falling out of trackTravel speed exceeds limit Spike checkDiscontinuities in SST time series along track SST gradient exceeds limit External consistency Reference Check Measurements deviating far away from reference Bayesian approach (*) (Ref. SST: Daily OI SST v2) Mutual consistency Cross- platform Check Mutual verification with nearby measurements (“buddies check”) Bayesian approach (*) based on space/time correlation of SST field (Correlation model: 2-scale SOAR, Martin et al., 2002) (*) Lorenc and Hammon, 1988; Ingleby and Haddleston, 2007

9 January 2014GOES-R SST Validation20

9 January 2014GOES-R SST Validation21 Monthly Statistical Summaries Outliers detected by each QC check Moments of ΔT S =T in situ - T Reynolds Histograms of ΔT S

9 January 2014GOES-R SST Validation22 Time Series of Monthly Statistics (1981-pr) No of Platforms No of Observations Bias in ΔT S SD of ΔT S ships drifters moorings

9 January 2014GOES-R SST Validation23 Monitoring individual platforms List of platforms & individual statistics Error Rate History Time Series of ΔT S Monthly Trajectory

9 January 2014GOES-R SST Validation24 Data for Download Last monthly file updated in NRT every 6hrs. Initial QC performed on the fly. Final QC requires ~7 days. QC’ed data in HDF format available for download (1981-pr)

9 January GOES-R SST Validation Status of NOAA SST Monitoring Well established for polar products AVHHR (NOAA, NAVO, EUMETSAT) MODIS-Terra, MODIS-Aqua (NOAA) VIIRS (NOAA) Progress made towards Monitoring Geo products Some elements of SQUAM and MICROS web design in place Prototyped using MSG SEVIRI (NOAA) Not linked to SQUAM and MICROS main pages yet

Future work 9 January 2014GOES-R SST Validation26 Polar Products Bring into SQUAM remaining community SST products - MOD28/MYD28 and (A)ATSR Update and unify functionality Geo products Complete development of Geo functionality in SQUAM and MICROS Set up match-up processing with iQuam in situ data Link to main SQUAM and MICROS pages Get ready for GOES-R launch!