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UP IN THE AIR * : Connecting plants, particles and pollution

UP IN THE AIR * : Connecting plants, particles and pollution. here!. Colette L. Heald Colorado State University. * Title taken from George Clooney & Paramount Photo taken from space shuttle Discovery. MIT March 11, 2011. ATMOSPHERIC COMPOSITION IS LINKED TO MAJOR ENVIRONMENTAL ISSUES.

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UP IN THE AIR * : Connecting plants, particles and pollution

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  1. UP IN THE AIR*: Connecting plants, particles and pollution here! Colette L. Heald Colorado State University * Title taken from George Clooney & Paramount Photo taken from space shuttle Discovery MIT March 11, 2011

  2. ATMOSPHERIC COMPOSITION IS LINKED TO MAJOR ENVIRONMENTAL ISSUES … AND DRIVEN BY THE BIOSPHERE CLIMATE AIR QUALITY / HEALTH FERTILIZATION

  3. NEED TO UNDERSTAND ATMOSPHERIC COMPOSITION BETTER NOW AND THEN PREDICT THE FUTURE… Problem: Observations are sparse over much of the globe SURFACE SITES AIRCRAFT CAMPAIGNS SATELLITES GLOBAL MODELS Past 2011 Future? Goal: Investigate global budgets, atmospheric sources and transformations

  4. + FEEDBACKS FROM CLIMATE CHANGE (moisture, precipitation, T, hv) ? + oxidants ↓ OH = ↑ CH4 lifetime EMISSIONS: Particles Organics Inorganics … O3 + oxidation DISTURBANCE: Fires, beetles, land use change ANTHROPOGENIC INFLUENCE ECONOMICS, POPULATION, ENERGY USE

  5. DUST FROM NORTH AFRICA: IMPACTING AQ AND THE BIOSPHERE DOWN-WIND More than half of dust emitted globally from N. Africa TOMS: June 13-21, 2001 summer winter/spring Miami (1989-1997) French Guiana (1978-1979) [Prospero et al., 1981] [Prospero et al., 1999]

  6. DUST TRANSPORT FROM NORTH AFRICA Annual Mean AOD SUMMER WINTER CALIOP MODEL CALIOP MODEL Global Model: GEOS-Chem(2x2.5) David Ridley (CSU)

  7. DEPOSITION OF AFRICAN DUST IN THE AMAZON MAR-MAY We estimate 13 Tg/yr transported to Amazon annually. This is ~25% of the P supply [Mahowald et al., 2005] for the Amazon. Otherwise from fires and biogenic particles? Impact of greening of the Sahel on productivity of the Amazon? [Ridley et al., in prep]

  8. ISOPRENE: CONTROLLING AIR QUALITY AND CLIMATE C5 H8: Reactive hydrocarbon emitted from plants (primarily broadleaf trees) Annual global emissions ~ equivalent to methane emissions CLIMATE Depletes OH(?) = ↑ CH4 lifetime AIR QUALITY + OH O3 E=f( ) IPCC, 2007

  9. ISOPRENE IN THE FUTURE NPP ↑ Temperature↑ 2000 2100 Methane lifetime increases [Shindell et al., 2007] SOA burden ↑ > 20% [Heald et al., 2008] Surface O3 ↑ 10-30 ppb [Sanderson et al., 2003] (US 8-hr standard = 75 ppb) Isoprene emissions projected to increase substantially due to warmer climate and increasing vegetation density.  LARGE impact on oxidant chemistry and climate 

  10. CO2 INHIBITION COMPENSATES FOR PREDICTED TEMPERATURE-DRIVEN INCREASE IN ISOPRENE EMISSION Standard model (MEGAN) Standard model + CO2 inhibition Empirical parameterization from plant studies [Wilkinson et al., 2009] 696 Eisop (TgCyr-1) 523 508 479 2000 2100 (A1B) * With fixed vegetation CONCLUSION: Isoprene emission predicted to remain ~constant Important implications for oxidative environment of the troposphere… Global Model: NCAR CAM3-CLM3 (2x2.5)

  11. UNLESS…CO2 FERTILIZATION IS STRONG • CLM DGVM projects a 3x increase in LAI associated with NPP and a northward expansion of vegetation. • [Alo and Wang, 2008] • Isoprene emissions more than double! (1242 TgCyr-1) • If include N limitation: • Only ~25% of the growth in NPP [Thornton et al., 2007; Bonan and Levis, 2010] Future land use may be the greatest uncertainty in chemistry-climate predictions [Heald et al., 2009]

  12. ORGANIC AEROSOL: THE MESSIEST AEROSOLS! Primary Organic Aerosol: emitted Secondary Organic Aerosol: formed + oxidants These sources estimated ~ 50 TgC/yr Hydrocarbons (gas-phase & particulate) Terpenes (gas-phase) ANTHROPOGENIC NATURAL

  13. ORGANIC AEROSOL MAKES UP AN IMPORTANT/DOMINANT FRACTION OF OBSERVED AEROSOL Sulfate Organics [Zhang et al., 2007] Globally makes up 25-75% of total fine aerosol at the surface (ignoring dust here)

  14. MODELS UNDERESTIMATE OBSERVED ORGANIC AEROSOL 2001-2009 OA Mass (fine) 2-10! Model underestimate observed OA concentrations by factor of 2-10 in the mean. Big Issue in the community: What is the source of “missing OA”. [Heald et al. in prep] Global Model: GEOS-Chem(2x2.5)

  15. PRIMARY BIOLOGICAL AEROSOL PARTICLES (PBAP) ALGAE VIRUSES BACTERIA POLLEN FUNGUS Jaenicke [2005] suggests may be large (1000s Tg/yr) Elbert et al. [2007] suggest emission of fungal spores ~ 25 TgC/yr PLANT DEBRIS PBAP estimates ~1000 Tg/yr would swamp all other sources of organic aerosol. KEY QUESTION: what is the size (lifetime) of these particles??

  16. FIRST SIMULATION OF FUNGAL SPORE PBAP • Mannitol is a unique tracer for fungal spores [Bauer et al., 2008; Elbert et al., 2007]: 1 pg mannitol = 38 pg OM • Optimize model emissions as a function of meteorological and phenological parameters (wind, T, humidity, radiation, surface wetness, precipitation, leaf area index, water vapour concentrations, boundary layer depths) to match global observations of mannitol in PM Global Model: GEOS-Chem(2x2.5) 25% emitted in fine mode , makes up 7% of total fine mode OA source(~4 TgC/yr)

  17. WHEN AND WHERE MIGHT FUNGAL SPORES BE IMPORTANT? Simulated Seasonality Contribution of PBAP to surface OA (fine) Fungal spores make a modest but regionally important contribution to organic carbon aerosol budget. More observations needed to test… Not the missing source of OA Pronounced seasonality in extratropics (corresponding to vegetation cover), peaking in late-summer/fall as in measurements. [Heald and Spracklen, 2009]

  18. MARINE PBAP WIND Sea-spray emission Surfactant Layer (with Organics) Ocean SPRING (high biological activity) SeaWIFS Under biologically active conditions, OA has been observed to dominate sub-micron aerosol mass. [O’Dowd et al., 2004]

  19. IS THE OCEAN AN IMPORTANT SOURCE OF PBAP? Previous estimates range from 2.3 to 75 TgC/yr No marine OA With marine OA OA Emissions Global Model: GEOS-Chem(2x2.5) Observations from 5 ship cruises show that marine OA from 2 schemes (based on MODIS / SeaWIFSchlorphyll-a) of ~8 TgC/yr are more than sufficient to reproduce sub-micron OA. Not a large source of aerosol. Kateryna Lapina –submitted to ACPD

  20. CAN SATELLITE OBSERVATIONS SHED ANY LIGHT ON THE BUDGET OF OA? Bottom-up calculations suggest that SOA source may be anywhere from 140-910 TgC/yr [Goldstein and Galbally, 2007]. SATELLITE AOD Assumptions: Optical Properties Size Distributions Aerosol Distributions AEROSOL SPECIATED MASS CONCENTRATIONS Dust Organic aerosol Sulfate Sea Salt Nitrate Soot SURFACE REFLECTANCE

  21. ATTRIBUTE ENTIRE MODEL UNDERESTIMATE OF AOD TO ORGANICS DJF JJA Estimate that ~150 TgC/yr source is required to close the MISR-GEOS-Chem* discrepancy. MISR GEOS-Chem* MISR- GEOS-Chem* *excluding OA

  22. HAVE WE REDUCED THE UNCERTAINTY ON THE OA BUDGET? 910 This is more than THREE TIMES what is currently included in global models…. BUT at the low end of Goldstein & Gallbally [2007] range. Missing source likely SOA. Range estimated by: Goldstein and Galbally [2007] 140 Our satellite top-down estimate 150 47 Existing GEOS-Chem sources All units in TgCyr-1 [Heald et al., 2010]

  23. ATMOSPHERIC AMMONIA: A FUTURE CONTROL ON PM? …stretching the definition of “natural” to include agriculture Biomassburning Agriculture Animals NH3 emissions major source of fixed N HNO3 NH3 (NH4)2SO4 (acidic) SO42- NH4 NO3 IF NH3 left-over SO2 …but NH3 is tough to measure

  24. NEW GLOBAL MEASUREMENTS OF AMMONIA FROM SPACE Summer 2009 NH3 Columns GEOS-Chem (with IASI operator) IASI (DOFS > 0.05) IASI – GEOS-Chem High values observed at Bakersfield during CalNex 2010 60 ppb Jennifer Murphy (U. Toronto) *preliminary IASI obs (ULB) Large model underestimate in Southern California! Emissions? Thermodynamic processing? Bi-directional flux?

  25. Emphasized here: investigating emissions from the biosphere (their importance for AQ, climate & productivity) Also critical: the role of these (and other) emissions in changing the chemical environment of the atmosphere The “natural” atmosphere is poorly understood, variable, and a key baseline against which to assess anthropogenic influence. + oxidants OA (PBAP) EMISSIONS: Particles Organics NOx … DUST ISOPRENE O3 + oxidation ANTHROPOGENIC INFLUENCE AMMONIA MARINE PBAP

  26. ACKNOWLEDGEMENTS David A. Ridley, Kateryna Lapina, Sonia Kreidenweis (CSU) Dominick Spracklen, Steve Arnold (Leeds University) Easan Drury (NREL) Russ Monson and Mick Wilkinson (UC Boulder) Alex Guenther (NCAR) Data: Hugh Coe, Gordon McFiggans, James Allan & Matthew Jolleys (U Manchester), Jose Jimenez (UC Boulder), Rodney Weber (G Tech), Ann Middlebrook & Tim Bates (NOAA), Lynn Russell & Lelia Hawkins (Scripps), Soeren Zorn (Harvard), Cathy Clerbaux and Lieven Clarisse (ULB), Jen Murphy (U of T) Satellite Data: Funding:

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