UP IN THE AIR

*

:

Connecting plants, particles and pollution

here!

Colette L. Heald Colorado State University MIT March 11, 2011 * Title taken from George Clooney & Paramount Photo taken from space shuttle Discovery

ATMOSPHERIC COMPOSITION IS LINKED TO MAJOR ENVIRONMENTAL ISSUES … AND DRIVEN BY THE BIOSPHERE

CLIMATE AIR QUALITY / HEALTH FERTILIZATION

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

DISTURBANCE: Fires, beetles, land use change + FEEDBACKS FROM CLIMATE CHANGE (moisture, precipitation, T, hv) ?

+ oxidants EMISSIONS: Particles Organics Inorganics …

↓ OH = ↑ CH

4 + oxidation

lifetime

O 3 ANTHROPOGENIC INFLUENCE ECONOMICS, POPULATION, ENERGY USE

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., 1999] [Prospero et al., 1981]

DUST TRANSPORT FROM NORTH AFRICA

Annual Mean AOD CALIOP WINTER MODEL CALIOP SUMMER MODEL David Ridley (CSU)

Global Model: GEOS-Chem(2



x2.5



)

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]

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 CLIMATE Depletes OH(?) = ↑ CH 4 lifetime AIR QUALITY + OH O 3 E=f( ) IPCC, 2007

ISOPRENE IN THE FUTURE

NPP ↑ Temperature↑ 2000 2100 Methane lifetime increases [

Shindell et al

., 2007] Surface O 3 ↑ 10-30 ppb [

Sanderson et al

., 2003] (US 8-hr standard = 75 ppb) SOA burden ↑ > 20% [

Heald et al

., 2008] Isoprene emissions projected to increase substantially due to warmer climate  and increasing vegetation density.

LARGE impact on oxidant chemistry and climate 

CO 2 INHIBITION COMPENSATES FOR PREDICTED TEMPERATURE-DRIVEN INCREASE IN ISOPRENE EMISSION

Empirical parameterization from plant studies [Wilkinson et al., 2009] Standard model (MEGAN) Standard model + CO 2 inhibition 696 508 523 479 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



)

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

ORGANIC AEROSOL: THE MESSIEST AEROSOLS!

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

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)

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”.

Global Model: GEOS-Chem(2



x2.5



)

[Heald et al. in prep]

PRIMARY BIOLOGICAL AEROSOL PARTICLES (PBAP)

BACTERIA VIRUSES POLLEN FUNGUS PLANT DEBRIS ALGAE 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??

FIRST SIMULATION OF FUNGAL SPORE PBAP 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



)

25% emitted in fine mode , makes up 7% of total fine mode OA source(~4 TgC/yr)

WHEN AND WHERE MIGHT FUNGAL SPORES BE IMPORTANT?

Simulated Seasonality Contribution of PBAP to surface OA (fine) 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]

WIND

MARINE PBAP

Sea-spray emission SeaWIFS Surfactant Layer (with Organics) Ocean

SPRING (high biological activity)

Under biologically active conditions, OA has been observed to dominate sub-micron aerosol mass.

[O’Dowd et al., 2004]

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 / 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

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

AOD= z top 0     

Assumptions: Optical Properties Size Distributions Aerosol Distributions AEROSOL SPECIATED MASS CONCENTRATIONS Organic Sulfate Dust aerosol Sea Salt Soot Nitrate

SURFACE REFLECTANCE

ATTRIBUTE ENTIRE MODEL UNDERESTIMATE OF AOD TO ORGANICS DJF JJA MISR

Estimate that ~150 TgC/yr source is required to close the MISR-GEOS-Chem* discrepancy.

GEOS-Chem* MISR GEOS-Chem*

*excluding OA

HAVE WE REDUCED THE UNCERTAINTY ON THE OA BUDGET?

910 Range estimated by: Goldstein and Galbally [2007] 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.

140

150

47

Our satellite top-down estimate

Existing GEOS-Chem sources All units in TgCyr -1 [Heald et al., 2010]

ATMOSPHERIC AMMONIA: A FUTURE CONTROL ON PM?

…stretching the definition of “natural” to include agriculture SO 2 Agriculture Animals Biomass burning NH 3 emissions major source of fixed N

NH 3

HNO 3 (acidic) SO 4 2 (NH 4 ) 2 SO 4 IF

NH 3

left-over NH 4 NO 3 …but NH 3 is tough to measure

NEW GLOBAL MEASUREMENTS OF AMMONIA FROM SPACE Summer 2009 NH 3 Columns IASI (DOFS > 0.05) GEOS-Chem

(with IASI operator)

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?

MARINE PBAP DUST 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 + oxidants

The “natural” atmosphere is poorly understood, variable, and a key baseline against which to assess anthropogenic influence.

OA (PBAP) EMISSIONS: Particles Organics NOx … ISOPRENE + oxidation AMMONIA O 3 ANTHROPOGENIC INFLUENCE

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: