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Formaldehyde from Space: Unexplored regions, New Data, New Challenges.

Formaldehyde from Space: Unexplored regions, New Data, New Challenges. Paul Palmer University of Edinburgh. A modest beginning…. HCHO. NO 2. Thomas et al, GRL, 1998. Vertical column retrievals. 1) Direct fit of observed radiances: slant columns. 337-356 nm (O 3 , NO 2 , BrO, O 2 -O 2 ).

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Formaldehyde from Space: Unexplored regions, New Data, New Challenges.

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

  2. A modest beginning…. HCHO NO2 Thomas et al, GRL, 1998

  3. Vertical column retrievals 1) Direct fit of observed radiances: slant columns 337-356 nm (O3, NO2, BrO, O2-O2) Transmission 8 x 1016 molec cm-2 Chance et al, GRL, 2000 1 AMF = AMFG w()S()d 0 • Estimated Error Budget • Slant column fitting: 4x1016 molec cm-2 • AMF: • UV albedo (8%) • Model error (10%) • Clouds (20%) • Aerosols (20%) • Subtotal 30% • For a vertical column of 2x1016 molec cm-2 and AMF of 0.7 • TOTAL = 9x1015 molec cm-2 2) Air-mass factor calculation: vertical columns Normalised HCHO profile Radiative transfer Palmer et al, JGR, 2001

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

  5. hv O3 NO2 NO OH HO2 Direct intercontinental transport of pollutants A simplistic view of tropospheric chemistry Pyro-convection NOx, RH, CO O3 Visibility O3 Continent 1 Continent 2 Ocean physics, chemistry, biology

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

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

  8. hours hours HCHO h, OH OH kHCHO ___________ HCHO EVOC = (kVOCYVOCHCHO) WHCHO Isoprene a-pinene propane 100 km Distance downwind VOC source Relating HCHO Columns to VOC Emissions VOC Net Local linear relationship between HCHO and E EVOC: HCHOfromGEOS-CHEM CTM and MEGAN isoprene emission model Palmer et al, JGR, 2003.

  9. Isoprene Monoterpenes MBO May 2001 Isoprene largely from broadleaf (e.g., poplar, sweetgum, aspen and oak) Monoterpenes primarily from coniferous tree (pine, cedar, redwood) Jun 2001 Jul 2001 Aug 2001 Sep 2001 [1012 C cm-2 s-1]

  10. NOx = 1 ppb NOx = 0.1 ppb Master Chemical Mechanism yield calculations 0.5 Isoprene C5H8+OH(i) RO2+NOHCHO, MVK, MACR (ii) RO2+HO2ROOH ROOH recycle RO and RO2 Cumulative HCHO yield [per C] Higher CH3COCH3 yield from monoterpene oxidation  delayed (and smeared) HCHO production HOURS 0.4 Parameterization (1ST-order decay) of HCHO production from monoterpenes in global 3-D CTM  pinene ( pinene similar) DAYS Palmer et al, JGR, 2006.

  11. GEOS-CHEM Modeling Overview MCM: parameterized HCHO source from monoterpenes and MBO GEOS-CHEM global 3D chemistry transport model PAR, T Emissions ΩHCHO= SEISOP+B MODEL BIOSPHERE MEGAN (isoprene) Canopy model; Leaf age; LAI; Temperature; Fixed Base factors GEIA Monoterpenes; MBO; Acetone; Methanol SE USA Model HCHO column [1016 molec cm-2] model without isoprene Isoprene emission [1013 atomC cm-2 s-1] Monthly mean AVHRR LAI

  12. Seasonal Variation of Y2001 Isoprene Emissions May Aug Jun Sep 1012 atom C cm-2s-1 Jul 7 0 3.5 MEGAN GOME MEGAN GOME • Good accord for seasonal variation, regional distribution of emissions (differences in hot spot locations – implications for O3 prod/loss). • Other biogenic VOCs play a small role in GOME interpretation Palmer et al, JGR, 2006.

  13. MEGAN Obs GOME Isoprene flux [1012 C cm-2 s-1] Julian Day, 2001 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 May Jun July Aug Sep Atlanta, GA 199619971998199920002001 PROPHET Forest Site, MI Atlanta, GA GOME HCHO [1016 molec cm-2] Interannual Variation: Correlate with EPA isoprene surface concentration data. Outliers due to local emissions. PAMS Isoprene, 10-12LT [ppbC]

  14. May Jun Jul Aug Sep 1996 1997 1998 1999 2000 2001 GOME Isoprene Emissions: 1996-2001 Palmer et al, JGR, 2006. [1012 molecules cm-2s-1] 10 0 5

  15. Surface temperature explains 80% of GOME-observed variation in HCHO G98 fitted to GOME data GOME Isoprene Emissions [1012 atoms C cm-2s-1] G98 Modeled curves NCEP Surface Temperature [K] Palmer et al, JGR, 2006. Time to revise model parameterizations of isoprene emissions?

  16. Europe Curci et al, in prep, 2007

  17. “Normal” airmass flow 1400 40 35 1200 Isoprene (ppt) 30 Temperature (C) 1000 25 800 20 600 15 Stagnant airmass flow 400 10 200 5 0 0 4-Aug 2-Aug 6-Aug 8-Aug 27-Jul 29-Jul 31-Jul 12-Aug 16-Aug 10-Aug 14-Aug 18-Aug 20-Aug 22-Aug 24-Aug 26-Aug 28-Aug 30-Aug Ozone exceedances of 90 ppbv, summer 2003 (#days) 0-1; 1-5; 5-10; >10 Isoprene c/o Ally Lewis Correlation of high ozone with temperature is driven by: 1) Stagnation, 2)Biogenic hydrocarbon emissions, 3)Chemistry

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

  19. What Controls HCHO Columns Over Europe? v7-01-02 GEOS-CHEM HCHO Column in Summer NO ISOP/NO ANTHRO • Biogenic control of HCHO column: • Eastern Europe • Northern Europe • Iberian Peninsula • Turkey 0.4 1 1.2 ANTHROPOGENIC CONTROL BIOGENIC CONTROL (GEIA Emissions)

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

  21. GOME HCHO Columns Over Europe 1996-2000 Aug Mean Aug 1996 [1016 molec cm-2] 0.5 1.0 1.5 2.0 2.5 Data on a regular 0.5 x 0.5 degree grid

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

  23. Work in progress: inverting as a function of NOx rather than geography GEOS-CHEM NO2 Columns, Aug 2000 [1015 molec cm-2] GEOS-CHEM: Isoprene vs HCHO columns over Europe ΩHCHO= S EISOP+B ΩHCHO [1016 molec cm-2] L, M and H NOx a bit arbitrary Resulting inversion does not distinguish properly biogenic vs anthropogenic HCHO EISOP [1012 molec cm-2s-1]

  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. 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 Sep 1997 1997 1998 1999 2000 2001 X = Active Fire (ATSR) Monthly ATSR Firecounts Slant Column HCHO [1016 molec cm-2] Nov 1997 Day of Year

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

  29. Isoprene Limonene [ppb] monoterpene emission of Apeiba tibourbou 1500 40 1000 30 [°C] (µmol m-2 s-1) PAR 500 20 Beta-pinene temperature 10 6 limonene myrcene 5 b-pinene a-pinene 4 sabinene 3 (µg g-1 h-1) G93 for isop. emission rate (C) [sum of monoterpenes] 2 1 0 4 4 2 2 (mmol m-2 s-1) transpiration Time of Day (mg g-1 h -1) assimilation (C) 0 0 12:00 00:00 00:00 12:00 00:00 06:00 18:00 06:00 18:00 local time [hh:mm] Can isoprene explain the observed magnitude and variance of HCHO columns over the tropics? Africa Amazon C/o J. Kesselmeier C/o J. Saxton A. Lewis

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

  31. Biomass Burning: emissions and injection heights October 2006 ACE HCHO c/o P. Bernath OMI HCHO c/o T. Kurosu ATSR Firecounts • 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

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