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2012 IGARSS Conference 23-27 July 2012, Munich, Germany. SST from NPP/VIIRS Sasha Ignatov, Peter Minnett, Bob Evans, Doug May, Pierre LeBorgne, Bob Arnone, Sid Jackson. P. Dash, X. Liang, J. Stroup, Y. Kihai, B. Petrenko, J. Sapper, M. Bouali, K. Saha NOAA/NESDIS, CSU/CIRA, SSAI, Riverside
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2012 IGARSS Conference 23-27 July 2012, Munich, Germany SST from NPP/VIIRS Sasha Ignatov, Peter Minnett, Bob Evans, Doug May, Pierre LeBorgne, Bob Arnone, Sid Jackson P. Dash, X. Liang, J. Stroup, Y. Kihai, B. Petrenko, J. Sapper, M. Bouali, K. Saha NOAA/NESDIS, CSU/CIRA, SSAI, Riverside K. Kilpatrick U. Miami/RSMAS B. McKenzie, J.-F. Cayula NAVO SST from NPP/VIIRS
JPSS Program Scientist – Mitch Goldberg NPP Project Scientist – Jim Gleason JPSS Data, Products and Algorithms Team – Heather Kilcoyne, Janna Feeley, Bruce Gunther VIIRS Sensor Data Records (SDR; L1b) Team – Changyong Cao, Frank DeLuccia NESDIS/STAR JPSS Team – Ivan Csiszar, Laurie Rokke, Lihang Zhou Acknowledgements SST from NPP/VIIRS
Outline • NPP, JPSS, VIIRS • NPP – The Suomi National Polar-orbiting Partnership • JPSS – Joint Polar Satellite System • VIIRS – Visible/Infrared Imager/Radiometer Suite • JPSS SST Team & Products • JPSS IDPS – Interface Data Processing Segment • NOAA ACSPO – Advanced Clear-Sky Processor for Oceans, SEATEMP (NAVO), L2gen (U. Miami), OSI SAF (EUMETSAT) • ACSPO SST Imagery from VIIRS & MODIS • Monitoring and Validation of SSTs • ACSPO – IDPS Comparisons • AVHRR – MODIS – VIIRS SST Consistency • Monitoring and Validation of Radiances • Stability of VIIRS radiances • Consistency AVHRR MODIS SST from NPP/VIIRS
Definitions NPP – The Suomi National Polar-orbiting Partnership • Successfully launched on 28 October 2011 • Transition from NOAA/POES & NASA/EOS – to JPSS JPSS – Joint Polar Satellite System • US - European Cooperation • US Contribution: VIIRS onboard NPP/JPSS in 1:30am/pm orbit. Planned launches: JPSS-1 (2017), -2 (2022) • European contribution: AVHRR onboard Metop in 9:30am/pm orbit. Planned launches: Metop-B (Sep 2012), -C (2017?) VIIRS – Visible/Infrared Imager/Radiometer Suite • Builds on MODIS heritage: Multispectral, high spatial resolution, high radiometric accuracy imagery • Products: Raw Data Records (RDR; L1a); Sensor Data Records (SDR; L1b); Environmental Data Records (EDR; L2) - e.g. SST SST from NPP/VIIRS
JPSS Data Products: IDPS – Interface Data Processing Segment • Algorithms: IPO/NPOESS (Northrop Grumman Aerospace Systems) • Operational Products: IPO/NPOESS (Raytheon) IDPS (RDRs, SDRs, EDRs) SST from NPP/VIIRS
JPSS SST Team & VIIRS Products SST from NPP/VIIRS
Current IDPS Daytime SST Algorithm a0, a1, a2, a3: Regression coefficients T11: Brightness temperature at 11 mm T12: Brightness temperature at 12 mm RSST: Reference (First-Guess) SST (currently, NCEP GFS) z: Sensor View Zenith Angle The algorithm is stratified by T11-T12 with a switch point at 0.8 K. For the range of 0.6 K to 1.0 K results from the two stratifications are linearly interpolated. The regression coefficients are derived using match-ups with QCed in situ SSTs available from NOAA in situ Quality Monitor (iQuam) http://www.star.nesdis.noaa.gov/sod/sst/iquam/ SST from NPP/VIIRS
Current IDPS Nighttime SST Algorithm a0, a1, a2, a3: Regression coefficients T3.7: Brightness temperature at 3.7 mm T11: Brightness temperature at 11 mm T12: Brightness temperature at 12 mm RSST: Reference (First-guess) SST (currently, NCEP GFS) z: View Sensor Zenith Angle There is no stratification for the nighttime algorithm The regression coefficients are derived using match-ups with QCed in situ SSTs available from NOAA in situ Quality Monitor (iQuam) http://www.star.nesdis.noaa.gov/sod/sst/iquam/ SST from NPP/VIIRS
Examples ACSPO VIIRS and MODIS SST Imagery Gulf of Mexico 23 May 2012 – Night SST from NPP/VIIRS
NPP/VIIRS ACSPO SST 23 May 2012 0730-0740 UTC – Night – Swath Projection ACSPO_V2.10_NPP_VIIRS_2012-05-23_0730-0740_20120526.053954.hdf SST from NPP/VIIRS
Aqua/MODIS ACSPO SST 23 May 2012 0800-0805 UTC – Night – Swath Projection ACSPO_V2.10_AQUA_MODIS_2012-05-23_0800-0805_20120527.093405.hdf SST from NPP/VIIRS
NPP/VIIRS ACSPO SST 23 May 2012 0730-0740 UTC – Night – Mapped onto 0.8km grid ACSPO_V2.10_NPP_VIIRS_2012-05-23_0730-0740_20120526.053954.hdf SST from NPP/VIIRS
Aqua/MODIS ACSPO SST 23 May 2012 0800-0805 UTC – Night – Mapped onto 0.8km grid ACSPO_V2.10_AQUA_MODIS_2012-05-23_0800-0805_20120527.093405.hdf SST from NPP/VIIRS
Examples ACSPO VIIRS and MODIS SST Imagery Great Britain and Ireland 26 May 2012 – Day SST from NPP/VIIRS
NPP/VIIRS ACSPO SST 26 May 2012 1250-1300 UTC – Day– Swath Projection ACSPO_V2.10_NPP_VIIRS_2012-05-26_1250-1300_20120529.075657.hdf SST from NPP/VIIRS
Aqua/MODIS ACSPO SST 26 May 2012 1300-1305 UTC – Day– Swath Projection ACSPO_V2.10_AQUA_MODIS_2012-05-26_1300-1304_20120527.215350.hdf SST from NPP/VIIRS
NPP/VIIRS ACSPO SST 26 May 2012 1250-1300 UTC – Day– Mapped onto 0.8km grid ACSPO_V2.10_NPP_VIIRS_2012-05-26_1250-1300_20120529.075657.hdf SST from NPP/VIIRS
Aqua/MODIS ACSPO SST 26 May 2012 1300-1305 UTC – Day– Mapped onto 0.8km grid ACSPO_V2.10_AQUA_MODIS_2012-05-26_1300-1304_20120527.215350.hdf SST from NPP/VIIRS
Wind Speed 26 May 2012 – Day – 1° gridded NCEP GFS SST from NPP/VIIRS
ACSPO and IDPS SST Monitoring in SST Quality Monitor (SQUAM) www.star.nesdis.noaa.gov/sod/sst/squam/ SST from NPP/VIIRS
NIGHT: ACSPO L2 minus OSTIA L4 28 May 2012 • Deviation from Reference SST is flat & close to 0 • Residual Cloud/Aerosol leakages seen as cold spots SST from NPP/VIIRS
NIGHT: IDPS L2 minus OSTIA L4 28 May 2012 • More Cloud leakages in IDPS than in ACSPO • “Limb Cooling” – due to SST equations/coefficients SST from NPP/VIIRS
NIGHT: ACSPO L2 minus OSTIA L4 28 May 2012 • Shape close to Gaussian • Domain & Performance Stats close to expected SST from NPP/VIIRS
NIGHT: IDPS L2 minus OSTIA L4 28 May 2012 • IDPS sample +29% larger compared to ACSPO • Shape less Gaussian (negative Skew / increased Kurt) • increased STDV/RSD & Larger fraction of outliers SST from NPP/VIIRS
NIGHT 28 May 2012 – Summary ΔT = “VIIRS minus OSTIA” SST (expected ~0) • IDPS SST domain +29% larger & Stats degraded, compared to ACSPO • Gap between Conventional and Robust stats wider in IDPS - More outliers Analyses are routinely performed in SQUAM. Both IDPS and ACSPO products are being improved SST from NPP/VIIRS
NIGHT STD DEV wrt. OSTIA L4 Warm-Up Cool-Down Event IDPS shows larger STD DEV • AVHRR & MODIS SSTs are consistent • ACSPO VIIRS is consistent with MODIS & AVHRR • IDPS VIIRS EDR shows larger STD DEV SST from NPP/VIIRS
DAY STD DEV wrt. OSTIA L4 Warm-Up Cool-Down Event IDPS shows much larger STD DEV • AVHRR & MODIS SSTs are consistent • ACSPO VIIRS is consistent with MODIS & AVHRR • IDPS VIIRS EDR shows much larger STD DEV SST from NPP/VIIRS
VIIRS, MODIS, and AVHRR Radiance Monitoring in MICROS www.star.nesdis.noaa.gov/sod/sst/micros/ SST from NPP/VIIRS
M-O Biases and Double Differences (“DD”) • 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 SST from NPP/VIIRS
Fully automated Scripted/Croned Back-up processing enabled ACSPO: Identify clear-sky pixels (Fortran 95) MICROS: Generate stats (IDL) Post to web: Html/JS/JQuery/JQplot MICROS: Set-Up, Data Volumes, Processing Time # of clear-sky (night) ocean pixels and Processing Time for 24hrs of L1b data SST from NPP/VIIRS
Nighttime M-O Biases in MICROS-ACSPO @11µm • Shape close to Gaussian • M-O Bias close to zero, slightly positive (expected) • VIIRS consistent with AVHRR; Terra consistent with Aqua • 2 MODIS and AVHRR/VIIRS clusters shifted by 0.6K SST from NPP/VIIRS
Nighttime DD’s @3.7 µm (Ref=Metop-A GAC) N16: unstable & out of family VIIRS recalibration Aqua: out of family by 0.3K • All AVHRRs (except N16), Terra/MODIS, and VIIRS: consistent to within ±0.08K • Aqua and Terra MODIS inconsistent by 0.3K : Calibration problem • Aqua/MODIS out of family by 0.3K (CRTM coefficients in error) • VIIRS Cal Change 7 Mar 2012 reset BT@M12 by +0.13K; In-family SST from NPP/VIIRS
Nighttime DD’s @11 µm (Ref=Metop-A GAC) N16: unstable & out of family Terra & Aqua: out of family by 0.6K VIIRS recalibration • All AVHRRs (except N16) and VIIRS are consistent to within ±0.05K • Terra and Aqua/MODIS out of family by 0.6K (error in CRTM coefficients) • Cal Change 7 Mar 2012: Reset BT@M15 by +0.14K; Now better in family SST from NPP/VIIRS
Nighttime DD’s @12 µm (Ref=Metop-A GAC) N16: unstable & out of family VIIRS recalibration Terra & Aqua: out of family by 0.3K • All AVHRRs (except N16) and VIIRS are consistent to within ±0.08K • Terra and Aqua/MODIS out of family by 0.3K (error in CRTM coefficients) • VIIRS Cal Change 7 Mar 2012: BT@M15 +0.14K; Now better in family SST from NPP/VIIRS
Nighttime DD’s SST (Ref=Metop-A GAC) New Reg. Coeff. used VIIRS recalibration N16: unstable & out of family Terra & Aqua SSTs are in family, due to use of empirical regression • All AVHRRs (except N16), MODISs and VIIRS are consistent to within ±0.13K • VIIRS Cal Change 7 Mar 2012: SST +0.10K & Out of family • New regression coefficients on 3 May 2012: SST -0.15K & back in family SST from NPP/VIIRS
Liang, Ignatov, Saha Monitoring of IR Clear-sky Radiances over Oceans for SST from NPP VIIRS, Terra-Aqua MODIS, and NOAA-Metop AVHRR. Poster Session “Ocean Temperature and Salinity” Tuesday, 24 July @17:20-19:00 More on VIIRS – MODIS – AVHRR Radiance Consistency SST from NPP/VIIRS
NPP launch – 28 Oct 2011 Nadir door opens, VIS/NIR imagery acquired – 21 Nov 2011 Cryoradiator doors opens, IR imagery acquired – 18 Jan 2012 Thermal IR Cal updated – 7 Mar 2012 Sensor Data Records: Beta distributed via CLASS – June 2012 VIIRS Cloud Mask (VCM): Declared Beta – April 2012 (Performance for SST Remains suboptimal) IDPS SST to be declared Beta VCM + 4..5 months ACSPO SST Beta is available from NESDIS NPP VIIRS & SST Milestones SST from NPP/VIIRS
Summary VIIRS is a good instrument for SST • Radiances: Stable & consistent with AVHRRs • Imagery – comparable to or better than Aqua MODIS • In ACSPO, we consider generating Level 1.5 intermediate product: Destripe imagery & Fill in bow-tied deleted pixels MODIS • MODIS Terra-Aqua 3.7 µm inconsistent by 0.3K – working to fix • All MODIS bands out of AVHRR/VIIRS family by 0.3-0.6K. • Sensor is fine, CRTM coefficients in error – working to fix SST Products • IDPS EDR – quite a bit of cloud leakage in SST. Work is underway with the VIIRS Cloud Mask Team to fix, before declaring SST Beta • ACSPO Beta is available • SDRs available via CLASS – users can make their SST retrievals SST from NPP/VIIRS