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

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

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

4. DISTURBANCE: Fires, beetles, land use change EMISSIONS: Particles Organics Inorganics … + oxidants + oxidation O3O3 ANTHROPOGENIC INFLUENCE ↓ OH = ↑ CH 4 lifetime + FEEDBACKS FROM CLIMATE CHANGE (moisture, precipitation, T, hv) ? 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) [Prospero et al., 1999] [Prospero et al., 1981] French Guiana (1978-1979)

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

7. DEPOSITION OF AFRICAN DUST IN THE AMAZON 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] MAR-MAY

8. ISOPRENE: CONTROLLING AIR QUALITY AND CLIMATE C 5 H 8 : Reactive hydrocarbon emitted from plants (primarily broadleaf trees) Annual global emissions ~ equivalent to methane emissions + OH O3O3 Depletes OH(?) = ↑ CH 4 lifetime IPCC, 2007 CLIMATE E=f() AIR QUALITY

9. ISOPRENE IN THE FUTURE Isoprene emissions projected to increase substantially due to warmer climate and increasing vegetation density.  LARGE impact on oxidant chemistry and climate  20002100 NPP ↑ Temperature↑ Surface O 3 ↑ 10-30 ppb [Sanderson et al., 2003] Methane lifetime increases [Shindell et al., 2007] SOA burden ↑ > 20% [Heald et al., 2008] (US 8-hr standard = 75 ppb)

10. CO 2 INHIBITION COMPENSATES FOR PREDICTED TEMPERATURE-DRIVEN INCREASE IN ISOPRENE EMISSION CONCLUSION: Isoprene emission predicted to remain ~constant Important implications for oxidative environment of the troposphere… * With fixed vegetation 508 523 696 479 E isop (TgCyr -1 ) 20002100 (A1B) Standard model (MEGAN) Standard model + CO 2 inhibition Global Model: NCAR CAM3-CLM3 (2  x2.5  ) Empirical parameterization from plant studies [Wilkinson et al., 2009]

11. UNLESS…CO 2 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] [Heald et al., 2009] Future land use may be the greatest uncertainty in chemistry-climate predictions

12. + oxidants Terpenes (gas-phase) Hydrocarbons (gas-phase & particulate) ORGANIC AEROSOL: THE MESSIEST AEROSOLS! P rimary O rganic A erosol: emitted S econdary O rganic A erosol: formed NATURAL ANTHROPOGENIC These sources estimated ~ 50 TgC/yr

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

14. MODELS UNDERESTIMATE OBSERVED ORGANIC AEROSOL 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  ) 2001-2009 2-10! OA Mass (fine)

15. PRIMARY BIOLOGICAL AEROSOL PARTICLES (PBAP) POLLEN BACTERIA VIRUSES FUNGUS ALGAE PLANT DEBRIS Jaenicke [2005] suggests may be large (1000s Tg/yr) Elbert et al. [2007] suggest emission of fungal spores ~ 25 TgC/yr 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 25% emitted in fine mode, makes up 7% of total fine mode OA source(~4 TgC/yr) I.Mannitol is a unique tracer for fungal spores [Bauer et al., 2008; Elbert et al., 2007]: 1 pg mannitol = 38 pg OM II.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  )

17. WHEN AND WHERE MIGHT FUNGAL SPORES BE IMPORTANT? Pronounced seasonality in extratropics (corresponding to vegetation cover), peaking in late-summer/fall as in measurements. 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 [Heald and Spracklen, 2009] Simulated Seasonality Contribution of PBAP to surface OA (fine)

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

19. IS THE OCEAN AN IMPORTANT SOURCE OF PBAP? Previous estimates range from 2.3 to 75 TgC/yr No marine OAWith marine OA Observations from 5 ship cruises show that marine OA from 2 schemes (based on MODIS / SeaWIFS chlorphyll-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 OA Emissions Global Model: GEOS-Chem(2  x2.5  )

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

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

22. 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. HAVE WE REDUCED THE UNCERTAINTY ON THE OA BUDGET? 910 47 Existing GEOS-Chem sources 140 Our satellite top-down estimate 150 Range estimated by: Goldstein and Galbally [2007] All units in TgCyr -1 [Heald et al., 2010]

23. ATMOSPHERIC AMMONIA: A FUTURE CONTROL ON PM? Biomass burning AnimalsAgriculture …stretching the definition of “natural” to include agriculture …but NH 3 is tough to measure (acidic) SO 4 2- SO 2 HNO 3 NH 3 (NH 4 ) 2 SO 4 IF NH 3 left-over NH 4 NO 3 NH 3 emissions major source of fixed N

24. NEW GLOBAL MEASUREMENTS OF AMMONIA FROM SPACE IASI (DOFS > 0.05) GEOS-Chem (with IASI operator) IASI – GEOS-Chem Summer 2009 NH 3 Columns Large model underestimate in Southern California! Emissions? Thermodynamic processing? Bi-directional flux? High values observed at Bakersfield during CalNex 2010 Jennifer Murphy (U. Toronto) 60 ppb *preliminary IASI obs (ULB)

25. EMISSIONS: Particles Organics NOx … + oxidants + oxidation O3O3 ANTHROPOGENIC INFLUENCE ISOPRENE DUST OA (PBAP) MARINE PBAP 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. AMMONIA

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: