1. Page 1 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007 ATSR-2/AATSR Overlap Analysis Gary Corlett AATSR Validation Scientist

2. Page 2 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007 Spectral Profiles

3. Page 3 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007 Simulated Bias: Centre of Swath From Owen Embury (university of Edinburgh)

4. Page 4 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007 Compare AATSR and ATSR-2 BTs: Case 1 Nadir View Forward View

5. Page 5 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007 Compare AATSR and ATSR-2 BTs: Case 2 Nadir View Forward View

6. Page 6 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007 Compare AATSR and ATSR-2 BTs: Case 2 Nadir View Forward View

7. Page 7 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007

8. Page 8 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007

9. Page 9 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007

10. Page 10 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007

11. Page 11 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007

12. Page 12 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007

13. Page 13 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007 Effect of 12 micron BT offset AATSR SkinAATSR Bulk Match-upsNBiasSt. Dev.% ±0.3NBiasSt. Dev.% ±0.3 Day D2 UC43760+0.080.33N/A39264+0.240.3255.82 Night D2 UC47169 0.000.33N/A42742+0.150.3263.08 Night D3 UC47198 0.000.26N/A42765+0.160.2471.87 Day D2 UC*43759-0.190.33N/A39264-0.020.3270.46 Night D2 UC*47173+0.090.33N/A42742-0.110.3265.92 Night D3 UC*47198-0.060.26N/A42766+0.100.2477.46 Match-up data from Anne O’Carroll (Met Office) UC: December 2005 Case C coefficients; UC*: December 2005 Case C coefficients + 0.2 K added to all 12 micron BTs

14. Page 14 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007 Correct AATSR or ATSR-2 ? AATSR BulkATSR-2 Match-upsBias (K) Night D2 (A) -0.11-0.09 Night D3 (A) +0.10 Night D2 (B)+0.15+0.20 Night D3 (B)+0.16 Match-up data from Anne O’Carroll (Met Office) A: +0.2 K offset applied to AATSR BTs B: -0.2 K offset applied to ATSR-2 BTs

15. Page 15 GHRSST-PP 8 th Science Team Meeting, Melbourne, 18 th May 2007 Summary & Conclusions  Calibration offset seen between AATSR and ATSR-2 12 μm clear-sky sea BTs ATS_MET_2P and AT2_MET_2P products analysed Validation results suggest AATSR is incorrect RAL to analyse flight-spare FPA Long-wavelength out-of-band leakage is suspected Modelled by Dave Smith (RAL); to be tested by Edinburgh  The bottom line for GHRSST-PP users D3 SST estimates are ~ + 0.05 K too warm Retrieval is dependant on 3.7 µm channel D2 SST estimates are ~ - 0.04 K too cold Owing to opposite retrieval bias Will be factored into updated SSES