1. Ray Nassar, Jennifer Logan, Lee Murray, Lin Zhang, Inna Megretskaia Harvard University COSPAR, Montreal, 2008 July 13-19 Investigating Tropical Tropospheric O 3 and CO during the 2006 El Niño using TES observations and GEOS-Chem

2. El Niño Southern Oscillation (ENSO) Oceanic-Atmospheric phenomenon warm phase – El Niño cold phase – La Niña SST anomalies and changes in ocean circulation induce changes in atmospheric convection, precipitation and chemical composition … also Indian Ocean Dipole (IOD) both ENSO & IOD influence Indonesian region, but warm phases rarely coincide: 1963, 1972, 1997 and 2006 http://www.cgd.ucar.edu/cas/ Saji et al. (1999) Nature 5°N-5°S, 170-120°W Niño 3.4 ENSO IOD

3. Ozone during the 1997 El Niño “Asymmetric Dipole Anomalies” TOMS Tropospheric Column Ozone (TCO) residual MLS H 2 O at 215 hPa NOAA Outgoing Longwave Radiation (OLR) http://ggweather.com/enso/nino_regions.gif Chandra et al. (1998) GRL O3O3 H2OH2O OLR 1997 – 1996 Anomalies

4. Modeling O 3 during the 1997 El Niño Hauglustaine, Brasseur & Levine (1999) GRL MOZART model Sudo & Takahashi (2001) GRL CHASER model Trop Column Ozone from TOMS using Convective Cloud Differential technique Chandra et al. (2002) JGR GEOS-Chem model TCO using CCD, TOMS TOMS Aerosol Index for biomass burning -> Biomass Burning component -> Meteorology/Dynamics/Convection component Duncan et al. (2003) JGR GEOS-Chem, focus on biomass burning and lightning Chandra et al. (2002) JGR Observations Model

5. Tropospheric Emission Spectrometer (TES) High resolution Fourier Transform Spectrometer (FTS) on Aura, measures nadir IR emission, launched 2004 July 15, ~705 km sun-sync orbit GEOS-Chem Tropospheric Chemical Transport Model

6. Changes to O 3 and CO during the 2006 El Niño TES has well- characterized O 3 with ~2 DOFS in the troposphere and simultaneous coincident CO as proxy for biomass burning Logan et al. (2008) GRL 1) Does GEOS-Chem properly simulate CO and O 3 distributions during the El Niño? 2) How do biomass burning, lightning and transport contribute to enhanced tropospheric CO and O 3 ? 3) How can the model simulations be improved? TES

7. TES & GEOS-Chem LT CO: October 2006 TES v02 CO cloud and data quality flag filtered Constant TES prior based on 30ºS-30ºN July mean Horizontal 2ºx2.5º, Vertical average of 6 TES levels LT (825-511 hPa) Differences exceed TES CO biases of ±10%, Luo et al. (2007) JGR 2ºx2.5º resolution

8. TES & GEOS-Chem LT O 3 : October 2006 TES v02 O 3 cloud, data quality and emission layer flag filtered Constant TES prior based on 30ºS-30ºN July mean Horizontal 2ºx2.5º, Vertical average of 6 TES levels LT (825-511 hPa) Differences exceed TES O 3 biases of 3-10 ppb, Nassar et al. (2008) JGR 2ºx2.5º resolution

9. 2006–2005 CO Differences October November December GEOS-ChemTES Observations

10. Biomass Burning impact on CO TES Observations GEOS-Chem GFEDv2 2005 & 2006 GEOS-Chem GFEDv2 2005 both years October November December GFEDv2 = Global Fire Emissions Database (version 2) 8-day temporal resolution

11. 2006–2005 O 3 Differences October November December GEOS-Chem GFEDv2 2005 & 2006 GEOS-Chem GFEDv2 2005 both years TES Observations

12. Evolution of Indonesian CO plume ppb

13. CO and O 3 Lower Troposphere (LT) Timeseries Subtracted 6 ppbv from TES O 3 to account for bias determined in validation (Nassar et al., 2008 JGR) GFEDv2 TES GEOS-Chem wAK TES corrected TES GEOS-Chem wAK

14. Global Fire Emission Database v2 Methodology 1) MODIS fire counts (8-day) for timing and spatial distribution 2) Emission factors for each land type (savanna, tropical forest, temperate forest) and each chemical species

15. Updated 2006 Lower Trop Timeseries November GFEDv2 emissions increased 3x to account for smoldering peat fires GFEDv2

16. GEOS-Chem & Lightning Imaging Sensor (LIS) October November December GEOS-Chem 2006 Lightning Flashrate GEOS-Chem 2006-2005 LIS Observations 2006-2005 Note: Flashrates below a given absolute threshold were omitted for % differences NO x from lightning reacts with CO or hydrocarbons to form tropospheric O 3 Hamid et al. (2001) GRL, discuss lightning enhancement over Indonesia during 1997 El Nino

17. Updated 2006 Lower Trop Timeseries Scaling model lightning to LIS observations improves the O 3 timeseries but discrepancy remains

18. TES & GEOS-4 UT H 2 O comparison with O 3 anomalies

19. Outgoing Longwave Radiation (OLR) from NOAA and GEOS-4 *High OLR = Low Convection NOAA Indonesian OLR anomaly OLR YYYY – OLR climatology From Australian Bureau of Meteorology http://www.bom.gov.au/bmrc/clfor/cfstaff/matw/maproom/index.htm NOAA OLR 2006-2005 GEOS-4 OLR 2006-2005 W/m 2

20. Summary and Conclusions GEOS-Chem can simulate the main CO and O 3 features of the 2006 El Niño Biomass burning, lightning and transport are all important contributors to enhanced tropospheric O 3 during El Niño GFEDv2 must account for CO from smoldering fires GEOS-Chem should move away from climatological approach to lightning Improvements to GEOS meteorological fields such as H 2 O and deep convection fields will result in better simulations of atmospheric composition Acknowledgments: Work was funded by a NASA grant to Harvard University