Monitoring of IR Clear-sky Radiances over Oceans for SST (MICROS): Towards Establishing Cross-Calibration Links Between AVHRRs Onboard NOAA-16, -17, -18, -19 and MetOp-A

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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

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Acknowledgements

• 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

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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

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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
  130am/pm orbit. Planned launches JPSS-1 (2017),
  -2 (2022)
• European contribution AVHRR onboard Metop in
  930am/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

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JPSS Data Products IDPS Interface Data
Processing Segment
Role / Responsibility NOAA/POES and NASA/EOS NPOESS JPSS
Platform, Launch Vehicle Private Industry Private Industry Private Industry
Instruments Private Industry Private Industry Private Industry
Algorithms Government Private Industry In transition to Government
Data Products Government Private Industry IPO/NPOESS
Cal/Val Government Private Industry Government
Archival Distribution Government Government Government
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JPSS SST Team VIIRS Products
Product Data Producer Team Member(s) Domain Heritage Format Archive
IDPS IPO NPOESS Ignatov and Team Global New Hdf5 NOAA CLASS
ACSPO NOAA Ignatov Global AVHRR MODIS Hdf4 NOAA CLASS
L2gen U. Miami Evans Minnett Global MO(Y)D28 AVHRR (PF) Nc3 -
SEATEMP NAVO May Global AVHRR DEF BUFR JPL PO.DAAC
EUMETSAT OSI SAF Le Borgne North-Atlantic AVHRR Nc3 OSI SAF
Ocean Color NRL Bob Arnone Link to Ocean Color Cal/Val Link to Ocean Color Cal/Val Link to Ocean Color Cal/Val Link to Ocean Color Cal/Val
IDPS NGAS Sid Jackson Link to heritage IPO/NPOESS code Link to heritage IPO/NPOESS code Link to heritage IPO/NPOESS code Link to heritage IPO/NPOESS code
Monitored in SQUAM www.star.nesdis.noaa.gov/sod/sst/squam/ Monitored in SQUAM www.star.nesdis.noaa.gov/sod/sst/squam/ Monitored in SQUAM www.star.nesdis.noaa.gov/sod/sst/squam/ Monitored in SQUAM www.star.nesdis.noaa.gov/sod/sst/squam/ Monitored in SQUAM www.star.nesdis.noaa.gov/sod/sst/squam/ Monitored in SQUAM www.star.nesdis.noaa.gov/sod/sst/squam/ Monitored in SQUAM www.star.nesdis.noaa.gov/sod/sst/squam/
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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/
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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/
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Examples ACSPO VIIRS and MODIS SST Imagery
Gulf of Mexico 23 May 2012 Night
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NPP/VIIRS ACSPO SST 23 May 2012 0730-0740 UTC
Night Swath Projection
ACSPO_V2.10_NPP_VIIRS_2012-05-23_0730-0740_2012052
6.053954.hdf
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Aqua/MODIS ACSPO SST 23 May 2012 0800-0805 UTC
Night Swath Projection
ACSPO_V2.10_AQUA_MODIS_2012-05-23_0800-0805_201205
27.093405.hdf
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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_2012052
6.053954.hdf
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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_201205
27.093405.hdf
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Examples ACSPO VIIRS and MODIS SST Imagery
Great Britain and Ireland 26 May 2012 Day
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NPP/VIIRS ACSPO SST 26 May 2012 1250-1300 UTC
Day Swath Projection
ACSPO_V2.10_NPP_VIIRS_2012-05-26_1250-1300_2012052
9.075657.hdf
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Aqua/MODIS ACSPO SST 26 May 2012 1300-1305 UTC
Day Swath Projection
ACSPO_V2.10_AQUA_MODIS_2012-05-26_1300-1304_201205
27.215350.hdf
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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_2012052
9.075657.hdf
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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_201205
27.215350.hdf
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Wind Speed 26 May 2012 Day 1 gridded NCEP GFS
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ACSPO and IDPS SST Monitoring in SST Quality
Monitor (SQUAM) www.star.nesdis.noaa.gov/sod/sst/
squam/
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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

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NIGHT IDPS L2 minus OSTIA L4 28 May 2012

• More Cloud leakages in IDPS than in ACSPO
• Limb Cooling due to SST equations/coefficients

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NIGHT ACSPO L2 minus OSTIA L4 28 May 2012

• Shape close to Gaussian
• Domain Performance Stats close to expected

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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

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NIGHT 28 May 2012 Summary
?T VIIRS minus OSTIA SST (expected 0)
NOBS (ACSPO) Min/ Max Mean/ STD Med/ RSD Skew/ Kurt
ACSPO 84.0M (100) -9.4/ 13.1 0.01/0.53 0.01/0.43 0.2/ 4.4
IDPS 108.5M (129) -17.5/25.5 0.03/0.69 0.05/0.48 -0.1/15.3

• 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
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NIGHT STD DEV wrt. OSTIA L4

• AVHRR MODIS SSTs are consistent
• ACSPO VIIRS is consistent with MODIS AVHRR
• IDPS VIIRS EDR shows larger STD DEV

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DAY STD DEV wrt. OSTIA L4
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

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VIIRS, MODIS, and AVHRR Radiance Monitoring in
MICROS www.star.nesdis.noaa.gov/sod/sst/micros/
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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

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MICROS Set-Up, Data Volumes, Processing Time

• 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

of clear-sky (night) ocean pixels and
Processing Time for 24hrs of L1b data
4 AVHRR GACs (N-16, -18, -19, Metop-A) 1 AVHRR FRAC (Metop-A) MODIS Terra MODIS Aqua VIIRS/NPP
Clear Ocean Pixels / Night 3M 4 45M 35M 2 90M
CPU Hours ACSPOMICROS (0.7 0.60.1) 4 5 41 (5 41) 2 13 103
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Nighttime M-O Biases in MICROS-ACSPO _at_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

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Nighttime DDs _at_3.7 µm (RefMetop-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_at_M12 by
  0.13K In-family

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Nighttime DDs _at_11 µm (RefMetop-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_at_M15 by 0.14K
  Now better in family

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Nighttime DDs _at_12 µm (RefMetop-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_at_M15 0.14K Now
  better in family

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Nighttime DDs SST (RefMetop-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

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More on VIIRS MODIS AVHRR Radiance Consistency

• 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 _at_1720-1900

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NPP VIIRS SST Milestones

• 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

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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