1 / 22

Linelist Needs for the Atmospheric Chemistry Experiment

Linelist Needs for the Atmospheric Chemistry Experiment. Chris Boone and Peter Bernath Univ. of Waterloo, Waterloo, Ontario, Canada HITRAN 2006 Conference June 27, 2006. Atmospheric Chemistry Experiment.

craper
Download Presentation

Linelist Needs for the Atmospheric Chemistry Experiment

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. Linelist Needs for the Atmospheric Chemistry Experiment Chris Boone and Peter Bernath Univ. of Waterloo, Waterloo, Ontario, Canada HITRAN 2006 Conference June 27, 2006

  2. Atmospheric Chemistry Experiment • Satellite mission for remote sensing of the Earth’s atmosphere, with a primary focus on Arctic ozone • Developed by the Canadian Space Agency • Launched August 2003, science operations began February 2004 • Operating well, no major problems yet. • Currently funded through April 2007.

  3. Solar Occultation

  4. Instruments • Infrared Fourier Transform Spectrometer operating between 2 and 13 microns with a resolution of 0.02 cm-1 ( 25 cm MPD) • 2-channel visible/near infrared Imagers, operating at0.525 and 1.02 microns • UV / Visible spectrometer (MAESTRO) 0.285 to 1.03 microns, resolution ~1-2 nm • Suntracker • Startracker

  5. ACE-FTS (ABB-Bomem) Interferometer-side Input optics-side

  6. Excellent SNR Performance Note: after detector decontamination

  7. H2O HITRAN 2004: 7.746e-24, 0.06954 HITRAN 2006: 7.746e-24, 0.0768 DLR: 7.75e-24, 0.0768

  8. Occultation with less water The H2O lineshape problems only occur when working with high water levels (but not high enough for self-broadening parameters to be significant). When one has pressure broadening with lower water levels, the recently determined H2O broadening parameters give improved residuals.

  9. H2O lineshape • Major problems at low altitudes, makes it difficult to perform some retrievals in the lower troposphere. • Voigt lineshape inappropriate? • Variations along the line of sight playing some role? • HITRAN 2006 H2O parameters seem to improve fitting (2 decreases by 4 - 10%)

  10. CFC-113 Even in the low water case, large residuals from water lines complicate retrievals that need to go deep into the troposphere Bad water residual

  11. Version 2.2 Ozone • Validation results: ACE-FTS ozone ~5% low near the profile peak compared to other measurements. • Microwindows in two wavenumber regions: “Cleaner” region given greater weight and pulled the fit. Large residuals in the other region (compared to SNR)

  12. O3 ~3-4% increase between 15 and 50 km, leading to better agreement with other measurements.

  13. O3 parameters • Likely a ~4% discrepancy between the ozone line strength parameters in the two wavenumber regions. • Results from the lower wavenumber region agree better with validation data; suggests a problem with the higher wavenumbers.

  14. HNO3 Improved consistency with the HITRAN 2004 linelist (compared to previous versions), but there remains a significant discrepancy between the two wavenumber regions.

  15. N2 Improved N2 parameters from Aaron Goldman (see his poster for more details).

  16. C2H6 Q-branch Unidentified spectral features in C2H6 fitting microwindow

  17. C2H6 C2H6 Q-branches returned to the linelist, but of poorer quality than the feature near 2976.8 cm-1

  18. COClF Lab spectrum from Kitt Peak, courtesy of Curtis Rinsland

  19. COClF in ACE spectra ? ?

  20. Sparse Cross-Section Data • HNO4: 1 cross-section file, difficult to perform a retrieval • PAN: 2 files (2 different frequency regions) • HCFC-142b: 3 measurements (253, 270, and 287 K). Ideally, the data would go lower in T for atmospheric work • CH3CN: 3 measurements (276.1, 298.7, and 324.1 K). Again, ideally lower T.

  21. Conclusions • Strong push into troposphere: • Improved water • CFCs and HCFCs • Hydrocarbons (e.g., acetone, propane,…) • The listed errors on CO2 line intensities are 2-5%. The accuracy of everything ties back to CO2 (through pressure and temperature). It would be nice to have smaller errors.

More Related