Advanced Clear-Sky Processor for Oceans (ACSPO): Next-Generation Sea Surface Temperature (SST) Product

1. Advanced Clear-Sky Processor for Oceans (ACSPO): Next-Generation Sea Surface Temperature (SST) Product Presented by John Sapper

2. Requirements Weather & Water: • Increase lead-time & accuracy for Weather & Water warnings and forecasts • Improve predictability of hazardous and severe Weather & Water events • Increase development, application, & transition to operations and services • Reduce uncertainty of Weather & Water forecasts and assessments • Enhance environmental literacy, improve Weather & Water info and services Climate: • Develop an integrated global obs and data system to monitor climate • Understand climate forcing, Reduce uncertainty in climate predictions • Understand impact of climate variability on marine ecosystem • Enhance operational tools to support national socio-economic benefits Ecosystem: • Advance understanding of ecosystems and improve resource management • Explore our oceans, Forecast ecosystem events • Develop scenarios and build capacity to support regional management

3. Objectives, Benefits, Users Science: Develop flexible, state-of-the art Clear-Sky Ocean Processor in IR/VIS • Main product? Clear-Sky Radiances. Derived products? SST & Aerosol • Flexibility? Process Real time & historical data from various platforms & sensors • Innovation? Integrate sensor radiances with 1st guess SST/Upper Air fields via RTM Benefit: Enhanced CSR/SST products contribute towards improved • Operational Weather and Ocean Forecasting • Military and Defense Operations • Validating/Forcing Ocean and Atmospheric models • Ecosystem assessment, Tourism and Fisheries • Seasonal Forecasting, Climate Monitoring Users: NOAA, other National and International • NOAA/NWS (NCEP/EMC; CPC; OPC; Marine Forecast Offices and Centers) • NOAA/NOS; NOAA/NMFS; NOAA/OAR • NOAA/NESDIS (NODC; NCDC) • Department of Defense: US Navy • International: Group for High-Resolution SST (GHRSST)

4. Challenges and Path Forward • Science Challenges • Cross-platform/sensor consistency (AVHRR, MODIS, VIIRS) • Resolving diurnal cycle & skin-bulk difference • Next-generation AVHRR Climate Data Record (CDR) • Next Steps • Fully explore CRTM potential to improve SST Accuracy/Precision • Test with MODIS; Generate ACSPO products from VIIRS, ABI • Reconcile Radiances/SSTs from multiple sensors • Improve sensor calibration • Model Diurnal Variability & Skin-Bulk difference • Process NOAA-KLMNN’ (NOAA-15 and up) - First step towards CDR • Transition Path • Each new version of ACSPO is delivered to OSDPD & implemented into operations (2 upgrades since May 2008) • Working with NCEP users to implement ACSPO into NWS applications

5. ACSPO Team Project Co-Leads • Alexander Ignatov, Center for Satellite Applications and Research • John Sapper, Office of Satellite Data Processing and Distribution Development Team • Yury Kihai, STAR/Perot Systems • XingMing Liang, STAR/CIRA • Boris Petrenko, STAR/IMSG Group • John Stroup, OSDPD/Science & Technology Corp. • Denise Frey, OSDPD/Perot System Team Members • Prasanjit Dash, STAR/CIRA – SST Quality Monitor • Feng Xu, STAR/CIRA – In situ & Error Characterization support • Nikolay Shabanov, STAR/IMSG – adapt ACSPO to MSG/SEVIRI

6. NESDIS Operational POES SST • Past: Heritage Main Unit Task (MUT) – developed at NESDIS • 1981 - pr (Multi-Channel SST - McClain, 1985; Non-Linear SST - Walton, 1998) • 1993 - pr: Re-hosted to NAVOCEANO (“Shared Processing Agreement”). Robust end-to-end system but outdated. No redesign since 1981: Heavy data sub-sampling; No Radiative Transfer Model (RTM) & Reprocessing capability. • Present: New Advanced Clear-Sky Processor for Oceans (ACSPO) • Development started in late 2005 - Operational in May 2008 Process all AVHRR pixels (GAC, FRAC). RTM & Reprocessing capability. • Future: ACSPO in NPOESS era • Evaluate SST product generated by NPOESS contractor. Contractor’s cloud mask + Heritage NLSST algorithm. • Generate “AVHRR-like” ACSPO products from VIIRS radiances. Fall-back for NPOESS SST. Benchmark to measure VIIRS improvements. Continuity and smooth transition for SST users. Testing with MODIS underway.

7. ACSPO Premises • Emphasis on Clear-Sky Radiances rather than SST • CSR are assimilated and used for SST inversions at NCEP • Integrating satellite radiances with first-guess fields via CRTM • Improved cloud mask, SST retrievals, and QC of satellite radiances • Processing data from multiple platforms/sensors • Uniform products; Easier Development / Maintenance • Processing every clear-sky pixel over ocean - ×30 to ×50 higher density • Higher resolution & Accuracy SST analyses for user applications • Processing real-time and historical data • Uniform real-time and climate records; Easier Development/Maintenance • Online near-real time long-term monitoring, Cal/Val, and QC tools • Instant summary of product performance, self- & cross-platform consistency

8. ACSPO GAC (4km):Operational in May 2008 MUT SST ACSPO SST Full swath processed in ACSPO Data with θ>54° not processed in MUT Coverage Significantly improved in ACSPO compared to MUT

9. ACSPO FRAC (1km) from MetOp-AOperational in May 2009 1km Full Resolution Area Coverage (FRAC) AVHRR SST 4km Global Area Coverage (GAC) AVHRR SST Crisper SST patterns from hi-res data offer better potential for ocean dynamics and coastal studies

10. SST Validation against driftingand tropical moored buoys AVHRR SSTs are continuously validated against buoys http://www.star.nesdis.noaa.gov/sod/sst/calval/ Typically, agreement with in situ SST is within RMSD <0.4 K at night and <0.6 K during daytime

11. Online near-real timeSST Quality Monitor (SQUAM) AVHRR SSTs are continuously monitored against global analysis SST fields Typically, agreement with analysis SST is not as good as with in situ SSTs but.. http://www.star.nesdis.noaa.gov/sod/sst/squam/ Global analysis fields can be used to monitor satellite SST for stability, self- and cross-platform consistency

12. Online near-real time monitoringof Clear-Sky Radiances AVHRR clear-sky radiances are continuously monitored against CRTM simulations Typically, agreement between BTs from different platforms is within <0.1K NOAA-16 out of family: Terminator orbit; Sensor cal problems http://www.star.nesdis.noaa.gov/sod/sst/micros/ Excellent resource for calibration of satellite radiances and validation of CSR and CRTM

13. Conclusion • New Advanced Clear-Sky Processor for Oceans developed at NESDIS • Satellite radiances integrated with first-guess fields via CRTM (Improved cloud screening, Physical SST, Validation of sensor radiances) • Operationally processing real-time AVHRR data (GAC & FRAC) on 5 platforms • Testing underway with MODIS and NPOESS/VIIRS • Plan reprocess all AVHRR data back to 1981 (Climate Data Record) • ACSPO products • Major product: Clear-Sky radiances over Ocean • Derived Products: SST (IR) & Aerosol (VIS) • Improved resolution, coverage and accuracy compared to heritage • Online NRT monitoring & QC tools • Monitoring of IR Clear-Sky Radiances over Oceans for SST (MICROS) - see poster by Liang • SST Quality Monitor (SQUAM) – see poster by Dash • In situ SST Quality Monitor for Cal/Val (iQuam) – see poster by Xu

14. Challenges and Path Forward • Science Challenges • Cross-platform/sensor consistency (AVHRR, MODIS, VIIRS) • Resolving diurnal cycle & skin-bulk difference • Next-generation AVHRR Climate Data Record (CDR) • Next Steps • Fully explore CRTM potential to improve SST Accuracy/Precision • Test with MODIS; Generate ACSPO products from VIIRS, ABI • Reconcile Radiances/SSTs from multiple sensors • Improve sensor calibration • Model Diurnal Variability & Skin-Bulk difference • Process NOAA-KLMNN’ (NOAA-15 and up) - First step towards CDR • Transition Path • Each new version of ACSPO is delivered to OSDPD & implemented into operations (2 upgrades since May 2008) • Working with NCEP users to implement ACSPO into NWS applications

15. Back-Up slides

16. ACSPO will be employed with Future POES Platforms & Sensors 18 19 20 11 14 15 16 17 22 10 12 13 Launch Date 08 09 21 AVHRR-Europe (Global 1km) MetOp-A (10/2006) MetOp-B MetOp-C AVHRR-US (Global 4km) NOAA-15 (5/1998) NOAA-16 (9/2000) NOAA-17 (6/2002) NOAA-18 (5/2005) NOAA-19 (2/2009) MODIS Terra (12/1999) Aqua (5/2002) VIIRS NPP NPOESS C1 NPOESS C2

17. ACSPO Publications • CRTM in ACSPO • Liang, X., A. Ignatov, and Y. Kihai, 2009: Implementation of the Community Radiative Transfer Model (CRTM) in Advanced Clear-Sky Processor for Oceans (ACSPO) and validation against nighttime AVHRR radiances. JGR, 114, D06112. • Dash, P., A. Ignatov, 2008: Validation of Clear-Sky Radiances over Oceans Simulated with MODTRAN4.2 and Global NCEP GDAS Fields against nighttime NOAA15-18 and MetOp-A AVHRR data. Remote Sensing of Environment, 112, 6. • Cloud Mask in ACSPO • Petrenko, B., A. Ignatov, Y. Kihai, and A. Heidinger, 2009: Clear-sky mask for the Advanced Clear-Sky Processor for Oceans. JTech, submitted. • Online NRT monitoring & QC tools • Dash, P., A. Ignatov, Y. Kihai, and J. Sapper, 2009: The near real-time SST Quality Monitor (SQUAM) and its use for diagnostics of NESDIS heritage AVHRR products. JTech, submitted. • Xu, F., and A. Ignatov, 2009: Evaluation of in situ SSTs for use in the calibration and validation of satellite retrievals. JGR, submitted. • Liang, X., and A. Ignatov, 2010: Monitoring of IR Clear-sky Radiances over Oceans for SST: Near-Real Time Web-based Tool for Monitoring CRTM - AVHRR Biases. JGR, submitted.