Bridging Scales in Atmospheric Chemistry: from satellite to molecule Queen’s University January 30, 2013 Colette L. Heald Maria Val Martin, David A. Ridley

Atmospheric Composition is Linked to Major Environmental Issues AIR QUALITY / HEALTH VISIBILITY ACID RAIN CROP DAMAGE OZONE LAYER TOXIC ACCUMULATION CLIMATE FERTILIZATION

Scientific Challenge: Characterize the Emissions and Transformations Well Enough to Estimate Impacts Evolution of Pollution (Chemistry + Transport) Emissions 1.Anthropogenic pollution 2.Natural/biogenic Air Quality Impacts: 1.Visibility 2.Health 3.Agriculture Climate Forcing: 1.GHG warming 2.Aerosol warming/cooling

What’s Really the Problem? Diversity of Scales at Play, Coupled Physical & Chemical Processes local change in concentration with time transport (flux divergence; U is wind vector) chemical production and loss (depends on concentrations of other species) emission deposition Inflow F in Outflow F out X E Emission Deposition D Chemical production P L Chemical loss 1 box model Global Model

What Is An Aerosol? (also called particulate matter or PM) Particles in the atmosphere come from both natural and pollution sources, have a range sizes, properties and chemical complexity. They can be emitted directly (e.g. soot from diesel engine) or formed chemically (e.g. sulfate formed down-wind of a power plant) By 2030, PM will be the leading environmental cause of premature death (3.6 million deaths/year) [OECD, 2012] Scatter/absorb radiation and critical to cloud formation. The leading cause of uncertainty in climate forcing [IPCC, 2007]

Challenge: Heterogeneity of Atmospheric Composition GEOS-5 10 km aerosol model Many first order problems with atmospheric species (how much? what sources?) challenging to address because of the short lifetimes and varying properties of gases/particles in the atmosphere.

Solution: Satellite Observations! Otherwise observation network for tropospheric composition is sparse Tropopause (8-18 km) TROPOSPHERE STRATOSPHERE aircraft 22 km Surface sites ships, islands, buoys Satellites solar backscatter atmospheric emission occultation lidar sonde

Remote Sensing: The Classic Inverse Problem ? Given observed spectra, what is the atmospheric state that produced it? Problems: 1.Non-uniqueness of solution (need to apply a priori information) 2.Discreteness of measurements of a smoothly varying function 3.Instability of the solution due to errors in the observations The whole field of retrieval theory/practice!

Sink: Oxidation by OH CO Lifetime = 1-2 months CH 4 NMHC OH Fossil Fuels Biomass Burning Biofuels LARGE uncertainties on bottom-up emission inventories “Simple” chemical evolution Carbon Monoxide: Tracer of Pollution

Carbon Monoxide Transpacific Transport Seen From Space Asian pollution exported via cold front Plume encounters a blocking H Pressure System and splits Elevated CO reaches North America Southern branch at low latitudes produces O 3 Feb 23 Feb 24 Feb 25 Feb 26 Feb 27 MOPITT GEOS-Chem x Avgker GEOS-Chem Total column CO [Heald et al., 2003b] Four such events observed in spring 2001.

Integration of Aircraft, Satellite and Models to Quantify Carbon Monoxide Sources from Asia OBSERVATIONSEMISSIONS Forward Model (GEOS-Chem CTM) Anthropogenic CO [Streets et al., 2003 and Logan & Yevich] Biomass Burning CO [Heald et al., 2003a] MOPITT CO TRACE-P Aircraft CO Inverse Model (Bayesian linear) Anthropogenic emissions underestimated (China = 39% too low) Biomass burning emissions too high (SE Asia = 50% too high) [Heald et al., 2004]

Dust From North Africa: Impacting Air Quality and Biospheric Productivity Down-Wind More than half of dust emitted globally from N. Africa TOMS: June 13-21, 2001 summer winter/spring Miami ( ) [Prospero et al., 1999] [Prospero et al., 1981] French Guiana ( ) Observation-poor so rely on models to estimate this. Satellites can provide much needed reality-check!

Using Satellite Observations to Test Simulation of Dust (1)Improve model simulation near source with better representation of particle size (2)Model removes too much dust during transport in winter. Reveals that deposition estimates to Amazon are likely a lower limit [Ridley et al., 2012] Seasonally averaged aerosol along Atlantic outflow transects Winter Summer Improve dust particle sizes

Using Satellite Observations to Constrain the Global Budget of Organic Aerosol [Heald et al., 2010b] MISR AOD Simulated AOD from OTHER aerosol Residual = Organic Aerosol Satellite measurements indicate that total OA source is capped at 150 TgC/yr (at lower end of previous estimate) This is still 3 times what is currently included in models. TgC/yr Summer ???

2012: Most Destructive Fires in Colorado History, with Air Quality Implications High Park Fire (June 2012) Waldo Canyon Fire (July 2012) Preliminary hourly/daily PM 2.5 and Satellite AOD over 10 Colorado sites Many local exceedances of daily PM 2.5 standard (over 100 µg/m 3 measured in Fort Collins!) Satellite aerosol observations (AOD) track surface PM observations EPA daily PM 2.5 standard 2012

Decadal Satellite Record Shows Large Aerosol Anomalies Associated with Both Local and Transported Smoke June 2002 [val Martin et al., in prep] MODIS Terra AOD anomalies August 2012 Hayman Fire High Park and Waldo Fires AZ Wallow Fire (2011) MT, WY, ID, WA Fires AZ, CA Fires CA Station Fire (2009)

Atmospheric Ammonia: A Source of Particulate Matter and Emissions on the Rise… AnimalsAgriculture NH 3 emissions major source of fixed N atmospheric acids (H 2 SO 4, HNO 3 ) Haber-Bosch Process (industrial production of NH 3 fertilizer) has dramatically increased global food production. …degrading air quality? now and in the future? Atmospheric NH 3 is difficult to measure [Erisman et al., 2008] + =

Insight Into Ammonia Sources over the US New satellite measurements offer unprecedented monitoring of NH 3. Comparison with model reveals springtime underestimate of emissions in the Midwest and year-round underestimate in the Central Valley of California (AQ exceedances). [Heald et al., 2012]

Atmospheric chemistry central to several environmental issues (air quality, climate, ecosystem health, etc) Atmospheric composition is highly heterogeneous. Satellite observations providing unprecedented constraints on emissions, transport and budgets of gases and aerosols in the atmosphere. (Eng Phys was surprisingly good preparation for all this!) Funding Acknowledgements: