1 / 26

GERB/CERES Shortwave and Longwave/Day Comparisons

Explore the comparative analyses of shortwave and longwave radiation data between GERB and CERES instruments, including detector-based and gridded comparisons for various campaigns. Find out about the operational criteria, matches, mean values, and conclusions drawn from the studies.

annied
Download Presentation

GERB/CERES Shortwave and Longwave/Day Comparisons

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. GERB/CERES Shortwave and Longwave/Day Comparisons Pamela E. Mlynczak1 G. Louis Smith2 Z. Peter Szewczyk1 1SAIC Hampton, VA 2National Institute of Aerospace Hampton, VA 24th GIST MeetingDecember 14-16, 2005

  2. Objectives • To date, we have conducted studies of four major campaigns when CERES was viewing scenes that were coaligned with GERB’s view. • Both pixel-by-pixel and gridded comparisons will be shown of SW unfiltered radiances. • I will also present our comparison of the CERES LW unfiltered radiances with those from GERB. 24th GIST MeetingDecember 14-16, 2005

  3. GERB/CERESSpecial Operations • December 2003/January 2004 15 days • June/July 2004 27 days • December 2004/January 2005 26 days • June 2005 21 days 24th GIST MeetingDecember 14-16, 2005

  4. Criteria for SW Matches – Detector-Based Comparison • Use GERB L1.5 NANRGs for time. • Use RMIB’s unfiltered SW radiances, angles, and geolocations for GERB. • Use CERES Edition 2 Revision 1 ES8s. • View zenith and relative azimuth angles within 5°. • Near GERB subsatellite point, accept matches within 10° angle between GERB & CERES rays. • Shows the ratio of mean GERB SW to mean CERES SW at each GERB detector. 24th GIST MeetingDecember 14-16, 2005

  5. CERES Matches for June 11, 2004 24th GIST MeetingDecember 14-16, 2005

  6. Latitude Coverage 24th GIST MeetingDecember 14-16, 2005

  7. Number of Matches for Each DetectorWinter Campaigns 24th GIST MeetingDecember 14-16, 2005

  8. GERB SW Mean/CERES SW MeanWinter Campaigns 24th GIST MeetingDecember 14-16, 2005

  9. Number of Matches for Each DetectorSummer Campaigns 24th GIST MeetingDecember 14-16, 2005

  10. GERB SW Mean/CERES SW MeanSummer Campaigns 24th GIST MeetingDecember 14-16, 2005

  11. GERB SW Mean/CERES SW MeanAll Campaigns – GERB V001 24th GIST MeetingDecember 14-16, 2005

  12. GERB SW Mean/CERES SW MeanGERB V999 Campaigns 24th GIST MeetingDecember 14-16, 2005

  13. Criteria for SW Matches – Gridded-Based Comparison • Use GERB L1.5 NANRGs for time. • Use RMIB’s unfiltered SW radiances, angles, and geolocations for GERB. • Use CERES Edition 2 Revision 1 ES8s. • View zenith angles within 5° and relative azimuth angles within 1° (due to hardware GERB mode). • Grid boxes are 1° x 1°. Need at least 4 GERB points and at least 8 CERES points in a box. • Shows the mean difference between GERB and CERES radiances for each latitude bin. 24th GIST MeetingDecember 14-16, 2005

  14. GERB SW – CERES SWDecember 2003/January 2004 24th GIST MeetingDecember 14-16, 2005

  15. GERB SW – CERES SWDecember 2004/January 2005 24th GIST MeetingDecember 14-16, 2005

  16. GERB SW – CERES SWDecember 2004 w/ GERB V999 24th GIST MeetingDecember 14-16, 2005

  17. GERB SW – CERES SWJune/July 2004 24th GIST MeetingDecember 14-16, 2005

  18. GERB SW – CERES SWJune/July 2004 w/ GERB V999 24th GIST MeetingDecember 14-16, 2005

  19. GERB SW – CERES SWJune 2005 24th GIST MeetingDecember 14-16, 2005

  20. Criteria for LW Matches • Use GERB L2.0 ARGs for LW radiances & time • Use RMIB’s geolocations for GERB • Use CERES Edition 2 ES8s • View zenith angles within 5° • Now comparison is based on the row in the ARG array, not GERB detector number 24th GIST MeetingDecember 14-16, 2005

  21. Number of Matches for Each ARG RowWinter Campaigns 24th GIST MeetingDecember 14-16, 2005

  22. GERB LW Mean/CERES LW MeanWinter Campaigns 24th GIST MeetingDecember 14-16, 2005

  23. Number of Matches for Each ARG RowSummer Campaigns 24th GIST MeetingDecember 14-16, 2005

  24. GERB LW Mean/CERES LW MeanSummer Campaigns 24th GIST MeetingDecember 14-16, 2005

  25. Conclusions • CERES has been operated in 4 campaigns (2 NH winters & 2 NH summers) to measure radiances which are co-aligned with GERB . • CERES serves as a transfer radiometer in comparing the 256 GERB detectors. • Conclusions apply to detectors 49-174. For detectors 1-48 and 175-256, the sampling is insufficient. • GERB detectors vary by ±2% among themselves. • Between adjacent detectors for SW, there is a random uncorrelated change of ~½% and a long range structure (over a score or more) of ±2%. • This structure is seen in V999 also. 24th GIST MeetingDecember 14-16, 2005

  26. Conclusions (cont.) • Differences between SW radiances are consistent between both comparison methods. • For detector-based, GERB/CERES ratio is in range of 0.93 to 0.97 for V001 and 1.03 to 1.08 for V999. • For gridded-based, relative difference is in range of –5.2% to –6.2% for V001 and 4.7% to 5.7% for V999. • For LW radiances, GERB/CERES ratio is in range of 1.00 ± 0.01. • Comparisons are reproducible within ±1% among campaigns. 24th GIST MeetingDecember 14-16, 2005

More Related