1. Formaldehyde from Space: Unexplored regions, New Data, New Challenges. Paul Palmer University of Edinburgh

2. A modest beginning…. Thomas et al, GRL, 1998 NO 2 HCHO

3. Vertical column retrievals 8 x 10 16 molec cm -2 Transmission Chance et al, GRL, 2000 337-356 nm (O 3, NO 2, BrO, O 2 -O 2 ) 1) Direct fit of observed radiances: slant columns AMF = AMF G  w(  ) S(  ) d  1 0 Radiative transfer Normalised HCHO profile Palmer et al, JGR, 2001 2) Air-mass factor calculation: vertical columns Estimated Error Budget Slant column fitting: 4x10 16 molec cm -2 AMF: 1)UV albedo (8%) 2)Model error (10%) 3)Clouds (20%) 4)Aerosols (20%) Subtotal 30% For a vertical column of 2x10 16 molec cm -2 and AMF of 0.7 TOTAL = 9x10 15 molec cm -2

4. biogenic, pryogenic, anthropogenic pryogenic anthropogenic biogenic anthropogenic pryogenic pyrogenic anthropogenic biogenic anthropogenic Thomas Kurosu, Harvard-Smithsonian HCHO August 2006 Ozone Monitoring Experiment Global distribution of HCHO, OMI August 2006

5. Continent 2 Direct intercontinental transport of pollutants O3O3 NOx, RH, CO Continent 1 O3O3 Ocean physics, chemistry, biology Pyro- convection HO 2 O3O3 NO OH NO 2 hv Visibility A simplistic view of tropospheric chemistry

6. Environmental factors: temperature solar irradiance leaf area index leaf age July 2003 MEGAN Isoprene Emission Inventory

7. North America Palmer et al, JGR, [2001, 2003, 2006] Abbot et al, GRL, 2003 Chance et al, GRL, 2000

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 CTM and MEGAN isoprene emission model Palmer et al, JGR, 2003. Net

9. May 2001 Jun 2001 Jul 2001 Aug 2001 Sep 2001 [10 12 C cm -2 s -1 ] Isoprene Monoterpenes MBO Isoprene largely from broadleaf (e.g., poplar, sweetgum, aspen and oak) Monoterpenes primarily from coniferous tree (pine, cedar, redwood)

10. Master Chemical Mechanism 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

11. Monthly mean AVHRR LAI MEGAN (isoprene) Canopy model; Leaf age; LAI; Temperature; Fixed Base factors GEIA Monoterpenes; MBO; Acetone; Methanol MODEL BIOSPHERE GEOS-CHEM Modeling Overview GEOS-CHEM global 3D chemistry transport model PAR, T Emissions MCM: parameterized HCHO source from monoterpenes and MBO model without isoprene Isoprene emission [10 13 atomC cm -2 s -1 ] Model HCHO column [10 16 molec cm -2 ] SE USA Ω HCHO = S E ISOP +B

12. 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.

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

15. Surface temperature explains 80% of GOME- observed variation in HCHO NCEP Surface Temperature [K] GOME Isoprene Emissions [10 12 atoms C cm -2 s -1 ] G98 fitted to GOME data G98 Modeled curves Time to revise model parameterizations of isoprene emissions? Palmer et al, JGR, 2006.

16. Europe Curci et al, in prep, 2007

17. 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) 0-1; 1-5; 5-10; >10 “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) Isoprene c/o Ally Lewis

18. Only continent where ANTHRO > BIO emissions [Simpson et al., JGR 1999] A = hot; B = warm temperate; C = cool temperate

19. What Controls HCHO Columns Over Europe? GEOS-CHEM HCHO Column in Summer BIOGENIC CONTROL NO ISOP/NO ANTHRO Biogenic control of HCHO column: Eastern Europe Northern Europe Iberian Peninsula Turkey (GEIA Emissions) 0. 4 1. 2 1 ANTHROPOGENIC CONTROL v7-01-02

20. EMEP Data GEIA MEGAN EMEP stations, Aug 2000 Comparison between GEOS-CHEM and EMEP data Isoprene (ppb) HCHO (ppb) Day, Aug 2000 Donon Some (limited) evidence that HCHO signal is biogenic MEGAN consistently too low

21. Aug 1996 1996-2000 Aug Mean GOME HCHO Columns Over Europe 2.52.01.51.00.5 [10 16 molec cm -2 ] Data on a regular 0.5 x 0.5 degree grid

22. Isoprene emission GEIA = Guenther et al, JGR (1995) Spatial separation method used for North America was not clean over Europe

23. Work in progress: inverting as a function of NO x rather than geography GEOS-CHEM NO 2 Columns, Aug 2000 [10 15 molec cm -2 ] GEOS-CHEM: Isoprene vs HCHO columns over Europe L, M and H NOx a bit arbitrary Resulting inversion does not distinguish properly biogenic vs anthropogenic HCHO Ω HCHO = S E ISOP +B E ISOP [10 12 molec cm -2 s -1 ] Ω HCHO [10 16 molec cm -2 ]

24. GOME isoprene flux have an uncertainty < 200%, comparable, if not less, that bottom-up inventories

25. Tropical Ecosystems Barkley and Palmer, WIP

26. Tropical ecosystems represent 75% of biogenic NMVOC emissions What drives observed variability of tropical BVOC emissions?

27. Slant Column HCHO [10 16 molec cm -2 ] Sep 1997 Nov 1997 1997 1998 1999 2000 2001 X = Active Fire (ATSR) Monthly ATSR Firecounts Day of Year Significant pyrogenic HCHO source over tropics Good: Additional trace gas measurement of biomass burning; effect can be identified largely by firecounts (see below) Bad: Observed HCHO a mixture of biogenic and pyrogenic – difficult to separate without better temporal and spatial resolution GOME

28. HCHO and Isoprene over the Amazon In situ isoprene 2002 Trostdorf et al, 2004 1997 1998 1999 2000 2001 GOME ATSR Firecounts used to remove HCHO from fires

29. Isoprene Limonene Beta-pinene [ppb] Time of Day C/o J. Kesselmeier C/o J. Saxton A. Lewis Amazon Africa Can isoprene explain the observed magnitude and variance of HCHO columns over the tropics?

30. The future? Newer orbits….better spatial and temporal resolution… Burrows et al, 2004

31. Biomass Burning: emissions and injection heights OMI HCHO c/o T. Kurosu ATSR Firecounts October 2006 ACE HCHO c/o P. Bernath Pyro-convective transport is difficult to model accurately. Two (or more) pieces of independent information allows a simultaneous inversion of surface emission and injection height. Schoeberl et al, 2006