1 / 16

Analysis of Satellite Observations to Estimate Production of Nitrogen Oxides from Lightning

Analysis of Satellite Observations to Estimate Production of Nitrogen Oxides from Lightning. Randall Martin Bastien Sauvage Ian Folkins. Chris Boone Peter Bernath. Jerry Ziemke. Chris Sioris. University of Saskatchewan.

stash
Download Presentation

Analysis of Satellite Observations to Estimate Production of Nitrogen Oxides from Lightning

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. Analysis of Satellite Observations to Estimate Production of Nitrogen Oxides from Lightning Randall Martin Bastien Sauvage Ian Folkins Chris Boone Peter Bernath Jerry Ziemke Chris Sioris University of Saskatchewan

  2. Global Lightning NOx Emissions Remain Poorly Constrained(1–13 Tg N/yr) 10-year Mean Flash Rate from the OTD & LIS Satellite Instruments Global rate 44±5 flash/sec [Christian et al. 2003] DJF 30 – 400moles NO per flash JJA Flashes km-2 min-1

  3. Top-down Information from the SCIAMACHY, ACE, OMI, and MLS Satellite Instruments SCIAMACHY Aug 2002-present Nadir spatial resolution 60x30 km2 Tropospheric NO2 Columns (Martin et al., in press) ACE-FTS Jan 2004-present Limb Measurements in the Upper Troposphere High Resolution FTS (33 species) HNO3 (Bernath et al., 2005; Boone et al., 2005) OMI & MLS Aug 2004-present Both instruments onboard Aura satellite OMI nadir UV-Vis, 24x13 km2 with daily global coverage MLS thermal emission microwave limb sounder Tropospheric O3 (Ziemke et al., in press)

  4. Current Estimate of Annual Global NOx Emissions Lightning 6 Tg N yr-1 Other NOx sources: (fossil fuel, biofuel, biomass burning, soils) 39 Tg N yr-1 1010 molecules N cm-2 s-1

  5. Tropospheric NO2 Columns Retrieved from SCIAMACHY Nov - Apr NO/NO2  w Altitude May - Oct Retrieval Uncertainty ±(5x1014 molec cm-2 + 30%) Tropospheric NO2 (1015 molecules cm-2) Martin et al., in press

  6. Simplified Chemistry of Nitrogen OxidesExploit Longer Lifetimes in Upper Troposphere Upper Troposphere hv NO Ozone (O3) NO2 O3,RO2 lifetime ~ month NOx lifetime ~ week HNO3 lifetime ~ weeks NO/NO2  with altitude Boundary Layer hv NO2 Ozone (O3) NO O3,RO2 lifetime ~ days NOx lifetime < day HNO3 Nitrogen Oxides (NOx)

  7. Strategy 1) Use chemical transport model to identify species, regions, and time periods dominated by the effects of lightning NOx emissions 2) Constrain lightning NOx emissions by interpreting satellite observations in those regions and time periods GEOS-Chem Chemical Transport Model • Assimilated Meteorology (NASA GMAO) • 2ox2.5o horizontal resolution, 30 vertical layers • O3-NOx-VOC chemistry • Lightning: 6 Tg N/yr, Price and Rind (1992), Pickering et al. (1998) • Aerosols: SO42--NO3--NH4+-H2O, dust, sea-salt, carbonaceous Bey et al., 1999 Fiore et al., 2002 Martin et al., 2002, 2003 Park et al., 2003, 2004 41 tracers ~90 species 300 reactions

  8. Calculated Monthly Contribution of Lightning and Soils to NO2 Column GEOS-Chem Tropospheric NO2 Column Column Fraction from Lightning (6 Tg N / yr) Column Fraction from Soils (6 Tg N / yr) Jan Jan Jul Jul 1015 molec cm-2 Unitless Unitless

  9. Annual Mean Tropospheric NO2 at Locations & Months with >50% of Column from Lightning and <25% from Soils SCIAMACHY (Uses 30% of Tropical Observations) Meridional Average GEOS-Chem with Lightning (6±2 Tg N yr-1) GEOS-Chem with Lightning (-18% bias, r=0.75) SCIAMACHY GEOS-Chem without Lightning (-72% bias, r=0.70) GEOS-Chem without Lightning NO2 Retrieval Error < 5x1014 molec cm-2 Tropospheric NO2 (1014 molec cm-2)

  10. ACE HNO3 over 200-300 hPa for Jan 2004 – Feb 2006 HNO3 Mixing Ratio (pptv) Data from Boone et al., 2005

  11. GEOS-Chem Calculation of Contribution of Lightning to HNO3 HNO3 With Lightning (6±2 Tg N yr-1) Focus on 200-300 hPa Fraction of HNO3 from Lightning No Lightning HNO3 from Lightning Fraction from Lightning Jan Jul Δpptv Unitless

  12. Annual Mean HNO3 Over 200-300 hPa at Locations & Months with > 60% of HNO3 from Lightning ACE (Uses 70% of Tropical Measurements) Smoothed Meridional Average GEOS-Chem with Lightning (6±2 Tg N yr-1) GEOS-Chem with Lightning (-1% bias, r=0.74) ACE GEOS-Chem without Lightning (-79% bias, r=0.15) GEOS-Chem without Lightning HNO3 Retrieval Error ~35 pptv HNO3 Mixing Ratio (pptv)

  13. OMI/MLS Tropospheric Ozone Column Jan Jul Dobson units Data from Ziemke et al. (in press)

  14. Calculated Monthly Contribution of Lightning to O3 Column O3 Column from Lightning Column Fraction from Lightning Jan Jul Unitless ΔDobson Units

  15. Annual Mean Tropospheric O3 Columns at Locations & Months with > 40% of Column from Lightning OMI/MLS (Uses 25% of Tropical Measurements) Meridional Average GEOS-Chem with Lightning (6±2 Tg N yr-1) GEOS-Chem with Lightning (4% bias, r=0.70) OMI/MLS GEOS-Chem without Lightning GEOS-Chem without Lightning (-42% bias, r=0.70) O3 Retrieval Error < 5 Dobson Units Tropospheric O3 (Dobson Units)

  16. Conclusions Global lightning NOx emissions are likely between 4 – 8 Tg N / yr 6 Tg N / yr is a best estimate Further refinement will require - improved satellite retrieval accuracy (i.e. NO2) - more observations (i.e. HNO3) - model development to better represent processes (i.e. soil NOx, vertical transport, ice uptake of HNO3) Acknowledgements • National Aeronautics and Space Administration (NASA) • Natural Sciences and Engineering Research Council of Canada (NSERC)

More Related