1. (Impacts are Felt on Scales from Local to Global) Aerosols Link Climate, Air Quality, and Health: Dirtier Air and a Dimmer Sun Emissions Impacts == 

2. Lifecycle of Particles in the Atmosphere Some particles are emitted directly (e.g., dust, black carbon), while others are formed as result of atmospheric chemistry (sulfate) Some emissions are due to natural process (e.g., sea salt), others due to anthropogenic activities (e.g., black carbon from coal combustion).

3. Models Play a Critical Role in Linking Emissions to Aerosol Distributions and Subsequent Effects Modeled Observed Aerosols and climate and air quality share: common emissions; common models; and synergistic control/policy strategies

4. Predicting Aerosol Distributions Have Added Complexities Of Emissions And Chemistry, And Size And Composition Matter! Maldives SSA Sub- micron Super Size: Data: ABC Project South Asia Aerosol Composition

5. Linking Emissions to Aerosol Distributions and Subsequent Effects How good are the models? What is the consistency of model-derived information? How model dependent are the results? How uncertain are the model predictions? What do the observations tell us about the quality of the calculation?

6. The Emission Estimates for Particles are Represent the Largest Source Of Uncertain Energy-related Open Burning BC Important – the lifetime of aerosols in the atmosphere is on the order of days, while that for CO2 is many decades 3.2 Tg/yr 5.8 Tg/yr ~25% biofuels % Uncertainty in Emissions

7. Model Intercomparison Studies Provide Valuable Information on Diversity of Model-Derived Information Does low diversity reflect scientific understanding or simply consensus? Textor et al., ACP, Atmos. Chem. Phys. Discuss., 5, 8331–8420, 2005 Comparison of 16 Global Aerosol Models

8. Black carbon at the Maldives Observed Modeled Predicted Surface Black Carbon Concentrations Despite High Uncertainty Current Models Have Significant Predictive Capabilities Data: ABC Project

9. Linking Aerosol Distributions to Radiative Effects Dust Nss Sulfate Organics Sea Salt Black Carbon Adding Observational Constraints Reduces Uncertainty

10. The Effect On Calculated AOD When Using Observational Parameterizations For Optical Properties Can Be Large Observations based on field experiments (in situ data) Bates et al., ACPD, 2006 A priori Constrained

11. Combining Satellite with Models Provides Improved Fields for Analysis How to optimally adjust individual aerosol quantities given AOD (sulfate, BC, OC, dust, sea salt)? - AOD by itself not unique - Fine mode fraction helps – allows sulfate, black carbon and organic carbon to be modified separately from dust and sea salt Apriori AOD Model Prediction AOD MODIS+AERONET AOD ADJUSTED MODEL Total Fine-fraction

12. Combining Satellite and Surface Measurements with Models Provides Improved Fields for Analysis How to optimally adjust individual aerosol quantities given AOD (sulfate, BC, OC, dust, sea salt)? - AOD by itself not unique - Fine mode fraction helps – allows sulfate, black carbon and organic carbon to be modified separately from dust and sea salt - SSA gives info to adjust absorption vs scattering – adjust black carbon separately from sulfate and organic carbon AOD MODIS+AERONET Total Fine-fraction Maldives We need more surface observations! (for validation)

13. Reductions Of Uncertainties When Measurements Are Used To Inform The Models Normalized uncertainties (uncertainty range of the indicated quantity divided by the value of the quantity) DRE: Direct radiative effect (all aerosols) DCF: Direct climate forcing (that portion due to anthropogenic aerosols) Bates et al., ACPD, 2006

14. Where do we go from here? Changes in China Emissions from 2001-2006 Due to Energy Growth and Improved Methodology SO2: +44% NOx: +65% CO: +57% VOC: +51% BC: +92% OC: +17%

15. 1993 2003 Hong Kong Guangzhou Another Twist to the Intercontinental Pollution Issue Development indicated by red and blue 50% higher than if done in the West !! Streets et al., ES&T, 2006

16. Heald et al., JGR, doi:10.1029/2005JD006847, 2006 (Emissions due to exports in PRD can be offset at an annual cost of $250 million, or 0.3% of total exports value) Emissions Due To Exports Have Significant Local Health/Climate Impacts AND They Contribute To Impacts in North America As Well! MODIS AOD Asia Contribution

17. Linking Emissions to Aerosol Distributions and Subsequent Effects -- Summary Models play an essential role. Models have improved substantially. Further improvements will require reductions in key uncertainties (e.g., emissions, better basic understanding of some processes). Closer integration of observations. Air quality and climate linkage offers synergistic policy/actions.

18. In the LMD-Z model, the change in net outgoing shortwave radiation in going from experiment 3 to experiment 4 is somewhat larger (−0.47Wm−2) than it is in going from experiment 4 to experiment 5 (−0.29Wm−2) but the change between experiment 4 and experiment 5 is still significant relative to the other changes introduced in these experiments. These changes are caused by large changes in the change in droplet concentrations (Fig. 3b) between the present day and pre-industrial simulations for experiment 5 compared to experiment 4, which are simply due to the large changes in present day and pre-industrial aerosols calculated by each of the models. Thus, within any one model, the change in net outgoing shortwave radiation is most sensitive to the calculation of individual aerosol fields than to anyof the other parameters in the cloud scheme.