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Aura meeting, Oct. 28, 2008.

Analysis of TES and MLS tropospheric data for ozone and CO in 2005 and 2006 using the GMI and GEOS-Chem global models. Jennifer A. Logan, Ray Nassar, Inna Megretskaia, Lin Zhang, Lee Murray, and the GMI, TES, and MLS teams Harvard University NASA/Goddard JPL. Aura meeting, Oct. 28, 2008.

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Aura meeting, Oct. 28, 2008.

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  1. Analysis of TES and MLS tropospheric data for ozone and CO in 2005 and 2006 using the GMI and GEOS-Chem global models. Jennifer A. Logan, Ray Nassar, Inna Megretskaia, Lin Zhang, Lee Murray, and the GMI, TES, and MLS teams Harvard University NASA/Goddard JPL Aura meeting, Oct. 28, 2008.

  2. The Global Modeling Initiative (GMI) ‘Combo’ Model • Combo = tropospheric + stratospheric chemical mechanism • GEOS-4 meteorological fields • 2° x 2.5° resolution • Aura4 simulation, 2004-2006 (2007 coming soon) • Model output is available to the community for Aura science • Output saved along satellite track at overpass times • GFED2 biomass burning emissions for 2004-2006 • MEGAN inventory for biogenics • Lightning NOx – regional scaling to average OTD/LIS lightning spatial patterns (Allen and Pickering). • GEOS-Chem similar, without stratospheric chemistry.

  3. Satellite data • TES V003 • Validated with ozonesondes by Lin Zhang, similar high bias to V002, 3-10 ppb. • Filters applied to remove “C-shaped” ozone profiles (Lin Zhang) • TES AKs and prior applied to model output • MLS data V2.2 • MLS AKs applied to model (makes very little difference)

  4. Outline • Use TES CO to evaluate model performance in lower troposphere to gain insight into reasons for discrepancies with MLS in the upper troposphere • Can the model match the interannual variability in tropical CO and ozone, and if not, why not? • Detailed model analysis of the high ozone over Indonesia and the Indian Ocean during the 2006 El Nino (GEOS-Chem study)

  5. S.H. biomass burning season, July-Oct. 2005 Too much export in easterlies in lower trop., convection N. of Equator TES, 700 hPa GMI (with AK) Model - TES July Aug. Sep. Oct. Fire emissions too low over Africa

  6. MLS CO at ~150 hPa, Aug-Nov. 2005 Not enough uplift over Himalayas MLS, 150 hPa GMI July Aug. Sep. Oct. Maximum from convection over S. America is a month late in model; not enough convective uplift in October.

  7. TES (LT) and MLS (UT) model differences July-Oct, 2005 GMI-TES, 700 hPa GMI-MLS, 150 hPa GMI matches model in LT, not in UT over Asia July High bias over north equatorial Pacific in LT and small high bias in UT. Aug. Sep. Oct. 50 -60 60 -50 CO (ppb)

  8. CO time series over South America MLS 150 hPa GMI Optical bench warm-up to improve CO signal TES, 700 hPa • Model matches TES in LT, but UT max. is one month too late • Problem with timing of convection rather than with fire emissions? • Is MLS CO biased high? Almost always higher than GMI in UT.

  9. TES, 700 hPa Dec Jan Feb Mar. April CO in NH burning season, Dec.2005-April 2006 MLS, 150 hPa LT max. in Dec. - Jan. UT max. in Feb. - Mar.

  10. Model discrepancies in tropics are smaller in Dec.-April. GMI-TES, 700 hPa GMI-MLS, 150 hPa N. Africa looks OK in Dec-Feb. Dec Jan Feb. N. Africa too low in March, April. N. Pacific too low in April. Mar. April

  11. Time series over North Africa MLS 150 hPa GMI TES, 700 hPa • Model max. is too early in UT – but CO in LT decreases too early • Errors in timing of fire emissions rather than in convection?

  12. CO time series over Indonesia MLS 150 hPa GMI TES, 700 hPa El Nino in late 2004 and 2006 with major fires in Indonesia

  13. CO tape recorder, 10 N- 10 S MLS Means for 2005 subtracted from time series GMI Combo CO relatively too low in SH burning season The GMI Combo model looks pretty good. Interannual variability driven by CO fire emissions, especially from Indonesia. Update of Schoeberl et al. (GRL, 2006), see also Combo model study of Duncan et al. (JGR,2007), with GCM met. fields.

  14. Ozone at 500 hPa in SH burning season, Sep.-Nov. 2005 TES GMI-TES Sep. Oct. Nov. -35 35 Ozone (ppb) South Atlantic is the largest discrepancy in the 2 years of comparisons with TES data. Problem also seen in model evaluation with sonde data.

  15. Ozone at 500 hPa, Sep.-Nov, 2006 Sep. Oct. Nov. Much smaller discrepancy in 2006. TES ozone higher in 2005, but GMI ozone higher in 2006 – why?

  16. Ozone in Oct 2006, 6º-14ºS TES vertical resolution ~6 km! GMI S. Amer. Africa GMI Ascension Island sondes Problem is in LT not UT. Ozone too low over Africa, so outflow from Africa does not supply S. Atlantic with enough ozone

  17. Ozone over South America - CAUTION: TES vertical resolution ~6 km! TES ozone: 2005>2006 GMI ozone: 2005<2006 In 2006, lower fire emissions (GFED), slightly less lightning NOx (LIS). In GMI model, more lightning NOx in 2006 => more ozone. More quantitative analysis needed!

  18. High CO in Oct.-Nov. 2006 – major fires in Indonesia.Half month maps Average for 825-511 hPa Box used for analysis GEOS-Chem results 8 day GFED fire emissions Nassar et al, draft ms.

  19. CO in the lower troposphere, Sep.-Dec. in box region. TES 2005 2006 GFED2 emissions GEOS-Chem GFEDv2 emissions increased 3x in November to match CO data. MODIS hot spots may miss smoldering fires at end of the season. Nassar et al., draft ms

  20. Ozone in UT and LT, 2005 and 2006, Sept.-Dec. 2005 2006 GEOS-Chem with 3xNov. emissions TES corr. for bias Model with 2005 emissions Model ozone starts to decrease 2 weeks too early in 2006

  21. Ozone in 2006 over Indonesia Best case – 3xNov. Emissions Ratio of LIS lightning 2006:2005 applied to lightning NOx Ozone starts to decrease 2 weeks too early, and is too low in UT. Comparison of OLR suggests that convection may be too weak over Indonesia, too strong over Indian Ocean. We are pushing the model to a very high standard!

  22. Conclusions • Interpretation of MLS CO in upper trop. requires careful analysis of CO data in the lower trop., as errors in LT propagate to the UT. • Over S. America, GEOS-4 max. convection appears to be a month too late, but hard to tell for N. Africa as errors in LT CO. • TES reveals interannual variability in tropical ozone, but model has problems matching this in S. Atlantic, likely due to lightning NOx. • Models match IAV in CO, ozone and H2O over Indonesia and neighboring regions very well, except for 2 week problem for ozone.

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