1. What have I learnt about tropospheric composition using space-based observations? Paul Palmer, University of Leeds www.env.leeds.ac.uk/~pip

2. Correlation of high ozone with temperature is driven by: 1) Stagnation, 2) Biogenic hydrocarbon emissions, 3) Chemistry Ozone exceedances of 90 ppbv, summer 2003 (#days) Model values for preindustrial ozone } European mountain- top observations [Marenco et al., 1994] Observed rise in ozone background at northern midlatitudes 0-1; 1-5; 5-10; >10 60 50 40 30 20 10 0 1870189019101930195019701990

3. NO HO 2 OH NO 2 O3O3 hv HC+OH  HCHO + products NOx, HC, CO Tropospheric O 3 is an important climate forcing agent IPCC, 2001 Level of Scientific Understanding Natural VOC emissions (50% isoprene) ~ CH 4 emissions.

4. Bottom-up Isoprene emissions, July 1996 MEGAN 3.6 Tg C GEIA 7.1 Tg C [10 12 atom C cm -2 s -1 ] Guenther et al, JGR, 1995 EPA BEIS2 2.6 Tg C Pierce et al, JGR, 1998 Guenther et al, ACP, 2006 E = A ∏ i γ i Emissions (x,y,t); fixed base emissions(x,y); sensitivity parameters(t)

5. Global Ozone Monitoring Experiment (GOME) & the Ozone Monitoring Instrument (OMI) GOME (European), OMI (Finnish/USA) are nadir SBUV instruments Ground pixel (nadir): 320 x 40 km2 (GOME), 13 x 24 km2 (OMI) 10.30 desc (GOME), 13.45 asc (OMI) cross-equator time GOME: 3 viewing angles  global coverage within 3 days OMI: 60 across-track pixels  daily global coverage O3, NO2, BrO, OClO, SO2, HCHO, H2O, cloud properties Launched in 2004

6. GOME HCHO columns July 2001 [10 16 molec cm -2 ] 0 1 2 0.5 1.5 2.5 Biogenic emissions Biomass burning * Columns fitted: 337-356nm * Fitting uncertainty < continental signals Data: c/o Chance et al

7. MayJunJulAugSep 1996 1997 1998 1999 2000 2001 GOME HCHO column [10 16 molec cm -2 ] 0 1 2 0.5 1.5 2.5 Palmer et al, JGR, 2006.

8. Relating HCHO Columns to VOC Emissions VOC HCHO hours OH hours h, OH Local linear relationship between HCHO and E k HCHO E VOC =  (k VOC Y VOC  HCHO )  HCHO ___________ VOC source Distance downwind  HCHO Isoprene  -pinene propane 100 km E VOC :  HCHO from GEOS-CHEM and MCM models Palmer et al, JGR, 2003. Net

9. MCM HCHO yield calculations Cumulative HCHO yield [per C]  pinene (  pinene similar) DAYS 0.4 Isoprene HOURS 0.5 NO x = 1 ppb NO x = 0.1 ppb Parameterization (1 ST -order decay) of HCHO production from monoterpenes in global 3-D CTM Higher CH 3 COCH 3 yield from monoterpene oxidation  delayed (and smeared) HCHO production Palmer et al, JGR, 2006. C 5 H 8 +OH  (i) RO 2 +NO  HCHO, MVK, MACR (ii) RO 2 +HO 2  ROOH ROOH  recycle RO and RO 2

10. Monthly mean AVHRR LAI MEGAN (isoprene) Canopy model Leaf age LAI Temperature Fixed Base factors MODEL BIOSPHERE GEIA Monoterpenes MBO Acetone Methanol Modeling Overview GEOS-CHEM Global 3D CTM PAR, T Emissions MCM: parameterized HCHO source from monoterpenes and MBO

11. Seasonal Variation of Y2001 Isoprene Emissions Good accord for seasonal variation, regional distribution of emissions (differences in hot spot locations – implications for O 3 prod/loss). Other biogenic VOCs play a small role in GOME interpretation May Jun Aug Sep Jul 0 3.5 7 10 12 atom C cm -2 s -1 GOMEMEGAN GOME Palmer et al, JGR, 2006.

12. GOME Isoprene Emissions: 1996-2001 MayJunJulAugSep 1996 1997 1998 1999 2000 2001 [10 12 molecules cm -2 s -1 ] 0 5 10 Relatively inactive Palmer et al, JGR, 2006.

13. Isoprene flux [10 12 C cm -2 s -1 ] Julian Day, 2001 MEGAN Obs GOME Sparse ground-truthing of GOME HCHO columns and derived isoprene flux estimates Seasonal Variation: Comparison with eddy correlation isoprene flux measurements (B. Lamb) is encouraging Atlanta, GA May Jun July Aug Sep PAMS Isoprene, 10-12LT [ppbC] GOME HCHO [10 16 molec cm -2 ] 1996 1997 1998 1999 2000 2001 Interannual Variation: Correlate with EPA isoprene surface concentration data. Outliers due to local emissions. Atlanta, GA PROPHET Forest Site, MI

14. Surface temperature explains 80% of GOME- observed variation in HCHO NCEP Surface Temperature [K] GOME HCHO Slant Column [10 16 molec cm -2 ] G98 fitted to GOME data G98 Modeled curves Time to revise model parameterizations of isoprene emissions? Palmer et al, JGR, 2006.

15. Tropical ecosystems represent 75% of biogenic NMVOC emissions 1996 1997 1998 1999 2000 2001 What controls the variability of NMVOC emissions in tropical ecosystems? Importance of VOC emissions in C budget? Kesselmeier, et al, 2002 GOME HCHO column, July

16. Challenges: Cloud cover, biomass burning, and lack of fundamental understanding of NMVOC emissions… OMI, 24/9-19/10, 2004 13x24 km 2 TES data @ 6km, 11/04 O3O3 CO MODIS Firecount O 3 -CO-NO 2 -HCHO- firecount correlations import to utilize when looking at the tropics Improved cloud- clearing algorithms and better spatial resolution data help. TES data c/o Bowman, JPL A more integrated approach to understanding controls of NMVOCs, e.g., surface data, lab data,

17. “Normal” airmass flow Stagnant airmass flow 0 200 400 600 800 1000 1200 1400 27-Jul29-Jul31-Jul 2-Aug 4-Aug 6-Aug8-Aug 10-Aug 12-Aug 14-Aug 16-Aug 18-Aug20-Aug22-Aug24-Aug26-Aug28-Aug30-Aug 0 5 10 15 20 25 30 35 40 Temperature (C) Isoprene (ppt) Estimated up to 700 extra deaths attributable to air pollution (O 3 and PM10) in UK during this period O 3 > 100 ppb on 6 consecutive days 2pm, 6 th Aug, 2003 Compiled from UK ozone network data Isoprene c/o Ally Lewis “Expect harmful levels of ozone and PM2.5 over the next couple of days; please keep small children and animals inside. Transatlantic pollution represents 20% of today’s UK surface ozone.” 2010

18. Resolution of new satellite data allows study UK AQ from space SCIA NO 2 @ 0.4x0.4 o, Aug 2004 GOME NO 2 @ 1x1 o Aug 1997 NAEI NO X emissions as NO 2, 2002 GOME and SCIA NO 2 c/o R. Martin; OMI (unofficial) NO 2 c/o T. Kurosu Length of day [hours] Day of Year Edinburgh, 56N Denver, 40N Cloud cover [%], ISCCP August 83-04 30 100 70 OMI NO 2 @ 0.1 o x0.1 o, Jul 2004

19. The increasing role of BVOCs: constraints from OMI HCHO? Stewart et al, 2003 Isoprene Monoterpenes BVOC fluxes for a “hot, sunny” day BOE: 0.5-1 ppb isoprene = 1-5x10 12 molec cm -2 s -1 (cf. SE USA 5-7x10 12 molec cm -2 s -1 ) 10 16 [molec cm -2 ] OMI HCHO 2 <0.3 NO 2 production ppb h -1 Isoprene HCHO c/o Jenny Stanton NO + RO 2  NO 2 + RO, Aug 2003

20. Unclear what PM characteristics affect health Secondary PM is formed from: –Oxidation of organic compounds –Oxidation of SO 2 –Difficult to estimate offline – need models and data MISR Surface PM2.5 = Model Surface [PM2.5] x MISR AOT Model AOT 2003 roadside (primary) PM10 MISR AOT can help estimate total PM2.5: Space-based aerosol optical properties can help map emissions of particulate matter Liu et al, 2004