# Presentation: 486303

## Ocean Products from MetOp AVHRR (“Product perspective to Sensors Cal/Val”)

- Alexander Ignatov and Yury Kihai NOAA/NESDIS/STAR & QSS Inc

- In collaboration with:
- Changyong Cao (STAR)
- Jerry Sullivan (STAR)
- Fred Wu

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

##  AVHRR SST and Aerosol: Very Sensitive to Instrument Calibration and Well-being

-  AVHRR SST and Aerosol: Very Sensitive to Instrument Calibration and Well-being

- METOP		(Oct’2006; 9:30AM)
- NOAA-18/N  	(May’2005; 2PM)
- NOAA-17/M	(Jun’2002; 10AM)
- NOAA-16/L  	(Sep’2000; 3PM)

- _Polar PSDI:_
-  1km SST/Aerosol from METOP
- _AVHRR Stewardship:_
-  Climate SST/Aerosol CDRs
-  Long-term AVHRR characterization

- Historically, SST (C. Walton) and Aerosol (N. Rao) scientists have been closely involved with AVHHR calibration. We continue to work closely with C. Cao, J. Sullivan, F. Wu.

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

##  Aerosol Jun 2005: 1

*** ***Aerosol Jun 2005: 1

- τ-errors: due to AVHRR calibration

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

##  Aerosol Jan 2006: 1

*** ***Aerosol Jan 2006: 1

- τ-errors: due to AVHRR calibration

*** ***AVHRR band 1:    N18, 17, 16 agree to within 1-2%.

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

##  Aerosol Jun 2005: 2

*** ***Aerosol Jun 2005: 2

- τ-errors: due to AVHRR calibration

- Error in AOD2 as a function of AOD2, for 4 levels of cal error from 5% to 20%.

*** ***AVHRR band 2:    N18 biased high by    ~-1% with respect to N17 and by ~-4% with respect to N16.

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

##  Aerosol Jan 2006: 2

*** ***Aerosol Jan 2006: 2

- τ-errors: due to AVHRR calibration

- 2 (0.83 m)

***N18 (2 PM)***

***N17 (10 AM)***

***N16 (3 PM)***

- Error in AOD2 as a function of AOD2, for 4 levels of cal error from 5% to 20%.

- AVHRR band 2:    N18, 17, 16 agree to within 1-2%.*** ***

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

## Day and Night SST products

***N18 (2 PM)***

***N17 (10 AM)***

***N16 (3 PM)***

- Nighttime SST (“152”)

- Daytime SST (“151”)

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

##  Validation vs. Drifting Buoys: Bias

*** ***Validation vs. Drifting Buoys: Bias

- Daytime bias (“151”)

**DAY:**

**NIGHT:**

**Split-window NLSST**

**Triple-window MCSST**

- Initially, bias is forced to “0”. But then it may change in time

- Nighttime bias (“152”)

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

##  Instruments change

*** ***Instruments change

- Ch3B (3.7 μm):

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

##  For complete N16/AVHRR story, see OSO Page.. http://www.oso.noaa.gov/poesstatus/componentStatusSummary.asp?spacecraft=16&subsystem=4 

*** ***For complete N16/AVHRR story, see OSO Page.. _[http://www.oso.noaa.gov/poesstatus/componentStatusSummary.asp?spacecraft](http://www.oso.noaa.gov/poesstatus/componentStatusSummary.asp?spacecraft=16&subsystem=4)__[=16&subsystem=4](http://www.oso.noaa.gov/poesstatus/componentStatusSummary.asp?spacecraft=16&subsystem=4)_

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

## AVHRR motor current and temperature

-     ..warmed up to improve lubrication

- N16 scan motor first spiked Sep 2003

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

## Temperatures of AVHRR 2-stage cooler

- 1st stage: Cooler (AVHRR temp)

-  2nd stage: Radiator

- MetOp AVHRR Radiator:
- ~10K warmer than N17

- MetOp AVHRR Cooler:
- ~10K warmer than N17

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

## Patch (Detector) Temperature

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD

## Summary

- Two AVHRR clear-sky products over ocean, Aerosol and SST, are very sensitive to sensor calibration anomalies
- Single-channel aerosol: Relating to cal anomalies straightforward
- SST: Thermal IR Cal sensitive to instrument temperature regime
- 	If our coefficients to convert telemetry to physical units is OK then
- MetOp AVHRR ~10K warmer than NOAA AVHRR
- 2nd stage cooler (radiator): 5-10K warmer on MetOp
- Patch: ~10K cooler than on NOAA
- Effect of temperature regime differences on SST is TBD

- MetOp Cal/Val Mtg-2,              WWB, Camp Springs, MD