Presentation is loading. Please wait.

Presentation is loading. Please wait.

GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 1 Rűdiger Lang, Rose Munro, Antoine Lacan, Richard Dyer, Marcel Dobber, Christian.

Similar presentations


Presentation on theme: "GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 1 Rűdiger Lang, Rose Munro, Antoine Lacan, Richard Dyer, Marcel Dobber, Christian."— Presentation transcript:

1 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 1 Rűdiger Lang, Rose Munro, Antoine Lacan, Richard Dyer, Marcel Dobber, Christian Retscher, Gabriele Poli, and Michael Grzegorski EUMETSAT GOME-2 AIRR: Angular dependence of the GOME-2 solar irradiance (AIRR) On-ground versus On-Board modelling

2 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 2 AIRR What is the AIRR elevation Azimuth On-groundIn-Orbit elevation Azimuth Season Daily Sun Meas. Sequence Instrument set-up layout, courtesy: TNO

3 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 3 AIRR What is the AIRR elevation Azimuth On-ground Discretisation Settings:On-ground results (example): Instrument set-up layout, courtesy: TNO FM3: Azimuth: 5 degrees (-317 to 333) Elevation: 0.75 degrees (-1.5 to 1.5) FM2: Azimuth: 2 degrees ( to 333.3) Elevation: 0.1 degrees (-1.5 to 1.5)

4 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 4 AIRR Specifications for FM-3/PGS 7 – Key-data for MME 1,irr PGS 7 page 96 and A (page 75) RA_ABS_IRR_MAIN.203 BSDF_AIRR.203

5 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 5 AIRR Specifications for FM-3/PGS 7 – Angle grid PGS 7 page 87

6 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 6 AIRR Simulation set-up Offline simulation of AIRR using EUM and FM2, as well as high resolution settings: High res. elevation grid (all): -1.5 to +1.5 at 0.1 degrees fixed grid Interpolated per individual solar measurement period from real elevation grid Medium res. FM2 SAA grid: to at 2 degrees grid (c.f. 5 degrees for FM3) Interpolated from all 365 solar measurements between June 2010 and June High res. SAA grid: to at 0.5 degrees grid (c.f. 5 degrees for FM3) Interpolated from all 365 solar measurements between June 2010 and June AIRR ( C ( ,e) ) is derived from raw calibrated signals and offline corrected for Dark current, normalised per integration time, Etalon, and PPG such that: C ( ,e) = S DNEP ( ,e) / S DNEP (  =325,e=0) For cross-checking the same is done with “half-calibrated spectra” S DNSE ( ,e)/M irr,1 and compared to original PPF-L1B data.

7 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 7 AIRR Simulation reference period Reference period has been shifted from 2007 (previous analysis) to June 2010-June /11 provides a much more quieter period (no instrument anomalies or switch-offs) with smaller degradation rate and better consistence between main channels and PMD

8 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 8 AIRR Disclaimer 1.Sorry! Its a 4D problem (I,  e  )! 2.All results are preliminary awaiting approval by level-2 retrievals!

9 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 9 AIRR – The angular resolution problem Measurements at FM3/Metop-A key-data elevation grid – operational setup Band 3 at 420 nm On-board Elevation: FM3 situation !

10 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 10 AIRR – The angular resolution problem Measurements at high res. fixed elevation grid – offline setup Band 3 at 420 nm On-Board Elevation: High- resolution/FM-2 situation !

11 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 11 AIRR – The angular resolution problem Comparison between current key-data and high res. elevation angle grid Elevation: Key-data – FM3 setup Elevation: OnBoard – High resolution/FM2 setup Band 3 at 420 nm

12 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 12 AIRR – derived from 2007 Measurements at high res. fixed azimuth grid – offline setup without de-trending Band 3 at 420 nm Azimuth: On-Board The zigzag features are the results of continuous degradation in combination with different SAA measured at different times throughout the year! Year 2007

13 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 13 AIRR – derived from 2010/11 Measurements at high res. fixed azimuth grid – offline setup without de-trending Band 3 at 420 nm Azimuth: On-Board Less zigzag because of smaller degradation rate throughout the year 2010/11! Year June June 2011

14 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 14 AIRR De-trending of results during 2011 – Band 3 / Channel 3 Signals are de-trended subtracting a simple (robust) linear gradient. June 2007 is used as reference point Previously the year 2007 was used which a much less stable situation and non-linear degradation -> introduction of lots of artefacts in the de-trending

15 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 15 AIRR De-trending of results during 2011 – Band 3 / Channel 3 Signals are de-trended subtracting a simple (robust) linear gradient. June 2007 is used as reference point Previously the year 2007 was used which a much less stable situation and non-linear degradation -> introduction of lots of artefacts in the de-trending [ show results per wavelength for de-trending]

16 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 16 AIRR Measurements at FM degree azimuth grid – offline setup de-trended Band 3 at 420 nm Azimuth: On-Board De-trended signals for June 2010 to June 2011 at FM2-2 campaign resolution of 2.0 degrees for SAA June 2010 to June 2011

17 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 17 AIRR Measurements at High. Res. 0.5 degree azimuth grid – offline setup de-trended Band 3 at 420 nm Azimuth: On-Board De-trended signals for June 2010 to June 2011 at FM2-2 campaign resolution of 2.0 degrees for SAA June 2010 to June 2011

18 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 18 AIRR – Recommendation for future Campaigns AIRR simulation at different resolutions – Band 3 SAA: 0.5 resolution (317 to 333) Elevation: 0.1 resolution (-1.5 to 1.5) Similar to L1-processor angle fine-grid as defined in initialisation file! Better discretisation balance!

19 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 19 AIRR FM2 calibration campaign settings – FM2 /Metop-B key-data set For the FM2-2 calibration campaign the following settings have been implemented: SAA: 2 degree resolution (316.7, 317 to 333, 333.3) Elevation: 0.1 degree resolution (-1.5 to 1.5) The recommended SAA resolution of 0.5 degrees could not be implemented because of time and stability constraints. This has been regarded as an acceptable compromise between time constraints and expected accuracy at the point of the decision in February 2011 (considering the lower frequency structures observed in SAA) For the future the measurement at 0.5 degrees is highly recommended

20 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 20 AIRR Results for detrended high-resolution AIRR from GOME-2 measurments 2010/2011 Band 3 at 420 nm On-Board Elevation: High- resolution/FM-2 situation !

21 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 21 AIRR Results for detrended high-resolution AIRR from GOME-2 measurments 2010/2011 Band 3 at 420 nm On-Board Azimuth: High- Resolution (recommended)

22 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 22 AIRR – Results On-Ground VS On-Board Simulated and key-data derived MME 1,irr Band 3 at 420 nm From key-data Simulated from 1 year of solar measurements 2010/2011 On-ground vs. On-Board Azimuth/ elevation: High- Resolution 0.5/0.1 degrees

23 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 23 AIRR – Results On-Ground VS On-Board Simulated and key-data derived MME 1,irr Channel 3 From key-data Simulated from 1 year of solar measurements 2010/2011 On-ground vs. On-Board Relative to Elevation = 0

24 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 24 AIRR Application of modelled AIRR (de-trended) to Solar Mean Reference spectra 17 th October 2007 On-ground On-board – New AIRR

25 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 25 AIRR Application of modelled AIRR (de-trended) to Solar Mean Reference spectra 17 th October 2007 On-ground vs. On-Board derived AIRR Impact on SMR main channel data

26 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 26 AIRR Application of modelled AIRR (de-trended) to Solar Mean Reference PMD spectra 17 th October 2007 On-ground vs. On-Board derived AIRR Impact on SMR PMD P-to-S ratio data

27 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 27 AIRR Application of modelled AIRR (de-trended) to Solar Mean Reference PMD spectra Impact on level 2 (preliminary!) 17 th October 2007 On-ground vs. On-Board derived AIRR Impact on ozone total column using GDOAS (Courtesy: O3MSAF/ BIRA) O3 (new AIRR) – O3 (FM3 key-data) [%]

28 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 28 AIRR Application of modelled AIRR (de-trended) to Solar Mean Reference PMD spectra Impact on level 2 (preliminary!) 17 th October 2007 On-ground vs. On-Board derived AIRR Impact on NO2 total column using GDOAS (Courtesy: O3MSAF/ BIRA) NO2 (new AIRR) – NO2 (FM3 key-data) [%]

29 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 29 AIRR Application of modelled AIRR (de-trended) to Solar Mean Reference PMD spectra Impact on level 2 (preliminary!) 17 th October 2007 On-ground vs. On-Board derived AIRR Impact on NO2 total column using GDOAS (Courtesy: O3MSAF/ BIRA) BrO (new AIRR) – BrO (FM3 key-data) [%]

30 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 30 AIRR Conclusions and Recommendations Overall: The impact of the difference between in-orbit modelled AIRR and the one that has been delivered in the key-data on the mean solar reference spectrum is small. But the spectral features are probably non-negligible and the impact may be different at various times per year (not fully investigated yet!). Preliminary: The impact on level-2 retrievals varies with the significance of the spectral features. Impact on TO3 is small whereas the impact on TNO2 and TBrO seems to be quite significant Recommendation: 1.To measure the AIRR on-ground on a 0.5 resolution grid for SAA and on a 0.1 resolution grid for elevation angle. 2.To smooth the data in spectral space and to improve on removal of “etalon-type” wiggles.

31 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 31 AIRR Conclusions and Recommendations The end

32 GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 32 NOAA results by Larry Flynn (41 st GSAG) EAST Version nm Reflectivity for a box in the Equatorial Pacific. The unadjusted values in the top plot reach a minimum of 8% (higher than expected for the open ocean) for the Nadir scan position. A single calibration adjustment lowers this value to 4% and also flattens out the scan dependence for West- viewing positions. The East-viewing results are not as good. |Lat|<5 Lon<-100 WEST


Download ppt "GOME-2 FM3 (Metop-A) Instrument Review, EUMETSAT, Darmstadt, June 2012 Slide: 1 Rűdiger Lang, Rose Munro, Antoine Lacan, Richard Dyer, Marcel Dobber, Christian."

Similar presentations


Ads by Google