Grantee Research Project Results
2009 Progress Report: Global Change and Air Pollution (GCAP) Phase 2: Implications for U.S. Air Quality and Mercury Deposition of Multiple Climate and Global Emission Scenarios for 2000-2050
EPA Grant Number: R833370Title: Global Change and Air Pollution (GCAP) Phase 2: Implications for U.S. Air Quality and Mercury Deposition of Multiple Climate and Global Emission Scenarios for 2000-2050
Investigators: Jacob, Daniel J. , Streets, David G. , Mickley, Loretta J. , Byun, Daewon , Rind, David , Seinfeld, John , Fu, Joshua
Institution: Harvard University , California Institute of Technology , NASA Goddard Institute for Space Studies , University of Tennessee , University of Houston , Argonne National Laboratory
Current Institution: Harvard University , Argonne National Laboratory , California Institute of Technology , NASA Goddard Institute for Space Studies , University of Houston , University of Tennessee
EPA Project Officer: Chung, Serena
Project Period: May 1, 2007 through April 30, 2011
Project Period Covered by this Report: May 1, 2009 through May 1,2010
Project Amount: $900,000
RFA: Consequences of Global Change For Air Quality (2006) RFA Text | Recipients Lists
Research Category: Climate Change , Air
Objective:
The overarching goal of GCAP Phase 2 is to better quantify and understand the effects of global change on air quality and mercury deposition in the United States over the coming decades. In GCAP Phase 1, also funded by the EPA, we developed a powerful set of modeling tools with which to attack this goal. We constructed interfaces between the GISS general circulation model (GCM), the GEOS-Chem global model of atmospheric composition, and the MM5/CMAQ regional air quality model. In GCAP Phase 2, we are exploiting these tools to address the following questions:
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How will 2000-2050 global change affect U.S. air quality under different greenhouse and anthropogenic emission scenarios, and what levels of confidence can be applied to model results?
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How will 2000-2050 changes in global anthropogenic emissions affect the intercontinental transport of air pollutants to the United States, and what will be the effects on U.S. air quality?
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How will 2000-2050 changes in anthropogenic emissions of mercury, together with changes in climate, affect deposition of mercury to U.S. ecosystems?
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Progress Summary:
We list here the major policy-relevant findings of GCAP Phase 2.
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Cyclone frequency has decreased over the 1980-2006 period, significantly offsetting ozone air quality gains [Leibensperger, et al., 2008].
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2000-2050 climate change (A1B scenario) is expected to increase surface ozone by 2-5 ppb in Midwest/Northeast and up to 10 ppb in pollution events [Wu, et al., 2008a; Lam. et al, in progress].
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Achieving a given air quality goal will require stronger pollutant emission reductions in future climate (“climate change penalty”) [Wu, et al., 2008a].
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Increasing methane and Asian NOx emissions are expected to increase policy-relevent-background ozone in the coming decades, but this may be partly offset by climate change except in the west [Wu, et al., 2008b].
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Climate change may increase PM2.5 in some U.S. regions by 0.1-1 µg m-3 due to increased stagnation, but this will be offset by SO2 emission reductions [Pye, et al., 2009; Kim, et al., in progress].
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Effect of climate change on air quality is far more uncertain (including in sign) for PM2.5 than for ozone [Jacob and Winner, 2009; Tai, et al., 2010].
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Global mercury emissions are expected to increase or stay flat in coming decades; increasing contribution from power plants will increase relative importance of regional sources [Streets, et al., 2009].
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Mercury deposition to the U.S. is expected to increase or stay flat, with increasing contributions from India and Mexico [Corbitt, et al., in progress].
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Increasing oceanic and soil emission of mercury (legacy of accumulated anthropogenic emissions) will partly offset future gains from mercury emission reductions [Corbitt, et al., in progress].
Future Activities:
Ongoing work in Phase 2 of GCAP includes the studies described below.
Investigation of observed ozone-temperature relationships as an indicator of the sensitivity of air quality to climate change. Our results show that the calculated sensitivity of surface ozone concentrations to temperature in the Southeast United States is sensitive to the fate of isoprene nitrate, a product of isoprene oxidation, by as much as ± 2 ppb/K. Preliminary results also suggest that future surface ozone concentrations in the Southeast may be governed in large part by factors other than temperature [Yoshitomi, et al., in preparation].
Improvements to traditional SOA representation in global models. Work is ongoing at Caltech to update the emissions of traditional biogenic SOA precursors (isoprene, monoterpenes, sesquiterpenes, and other terpenes) to MEGAN v2.04 or newer. For species such as sesquiterpenes, terpenoid alcohols, and terpenoid ketones, the emissions now are parameterized based on temperature, leaf age (diagnosed by changes in leaf area index [LAI]), LAI, and the photosynthetically active radiation flux. The emissions update leads to changes in the diurnal variation of the emissions as well as the magnitude of emissions in many locations. For consistency with the new emissions, the SOA precursor lumping has been revised slightly. Where appropriate, recent chamber data are used to update the SOA yields for isoprene and other terpenes [Pye, in progress].
Validation of sensitivity of PM2.5 to meteorological variables in GEOS-Chem. In this project, we are building on the work of Tai, et al. [2010], which quantified the sensitivity of observed PM2.5 to meteorological variables over the last 11 years. We now are comparing the observed sensitivities to those calculated by GEOS-Chem. We use Principal Component Regression (PCR) to quantify the contribution of different weather patterns to observed and modeled PM2.5 variability in seven regions across the United States. In this approach, we calculate daily averages of deseasonalized and normalized meteorological fields and PM2.5 concentrations for distinct regions, producing a single time series for each variable in each region. We next decompose the meteorology in each region into a set of linearly independent principal components (PCs). Each PC represents a unique set of meteorological conditions corresponding to a weather pattern. We then regress the normalized PM2.5 concentrations onto the PCs to quantify the contribution of each PC to PM2.5 variability. Comparison of the observed and modeled PC contributions will help us assess the capability of GEOS-Chem to quantify the response of PM2.5 to changing meteorological conditions [Tai, in progress].
Atmospheric mercury in a changing world. We are investigating the effect of changing mercury emissions, through application of the Streets, et al. [2009] mercury emissions inventory to GEOS-Chem. To this end, we have incorporated a tagged Hg capability into GEOS-Chem, which enables us to identify the source of Hg depositing at the earth’s surface and to evaluate the sensitivity of source-receptor relationships to the atmospheric redox mechanisms employed. We are in particular examining (1) the degree to which the uncertainty in Hg chemistry affects our estimate of future deposition rates and (2) how source-receptor relationships change with changing anthropogenic emissions in 2050 [Corbitt, in progress].
Global atmospheric model for mercury including oxidation by bromine atoms. Global models of atmospheric mercury generally assume that OH and ozone are the main oxidants converting Hg0 to HgII and thus driving mercury deposition to ecosystems. However, thermodynamic considerations argue against the importance of these reactions. We demonstrate the viability of atomic bromine (Br) as an alternative Hg0 oxidant. We conduct a global 3-D simulation with the GEOS-Chem model assuming Br to be the sole Hg0 oxidant (Hg+Br model) and compare to the previous version of the model with OH and ozone as the sole oxidants (Hg+OH/O3 model). We find that the Hg+Br and Hg+OH/O3 models are equally capable of reproducing the spatial distribution of total gaseous mercury (TGM) and its seasonal cycle at northern mid-latitudes, but only the Hg+Br model can reproduce the springtime depletion and summer rebound of TGM observed at polar sites [Holmes, et al., submitted].
Investigation of downscaling techniques, within-domain nudging. Fu and coworkers at University of Tennesee have developed an interface tool, GISS2MM5, which performs vertical interpolation and horizontal regridding of the global-scale meteorology for use in MM5. They also have explored the use of within-domain nudging in order to maintain dynamic consistency between GISS, the MM5 108-km simulation, and MM5 36-km simulation.
Effects of 2000-2050 climate change on regional air quality in the United States. Using the MM5/CMAQ modeling system, the University of Houston and University of Tennessee groups are both investigating the response of surface ozone to 2000-2050 A1B climate change. University of Houston calculates increases in MDA8 surface ozone concentrations across the eastern U.S. of 2-10 ppb in summer due solely to climate change, while University of Tennessee calculates little change in ozone in this region. The discrepancy in these results currently are being investigated. University of Tennessee calculates an increase in the ozone season in the future climate, with high ozone levels occurring in May and September.
Journal Articles on this Report : 13 Displayed | Download in RIS Format
Other project views: | All 52 publications | 24 publications in selected types | All 24 journal articles |
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Chen W-T, Lee YH, Adams PJ, Nenes A, Seinfeld JH. Will black carbon mitigation dampen aerosol indirect forcing? Geophysical Research Letters 2010;37:L09801 (5 pp.). |
R833370 (2009) R833370 (Final) |
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Fu JS, Jang CJ, Streets DG, Li Z, Kwok R, Park R, Han Z. MICS-Asia II:modeling gaseous pollutants and evaluating an advanced modeling system over East Asia. Atmospheric Environment 2008;42(15):3571-3583. |
R833370 (2009) R833370 (Final) R830959 (Final) |
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Fu JS, Streets DG, Jang CJ, Hao J, He K, Wang L, Zhang Q. Modeling regional/urban ozone and particulate matter in Beijing, China. Journal of the Air & Waste Management Association 2009;59(1):37-44. |
R833370 (2008) R833370 (2009) R833370 (Final) |
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Jacob DJ, Winner DA. Effect of climate change on air quality. Atmospheric Environment 2009;43(1):51-63. |
R833370 (2009) R833370 (Final) R830959 (Final) |
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Lam YF, Fu JS. A novel downscaling technique for the linkage of global and regional air quality modeling. Atmospheric Chemistry and Physics 2009;9(23):9169-9185. |
R833370 (2009) R833370 (Final) R830959 (Final) |
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Leibensperger EM, Mickley LJ, Jacob DJ. Sensitivity of US air quality to mid-latitude cyclone frequency and implications of 1980-2006 climate change. Atmospheric Chemistry and Physics 2008;8(23):7075-7086. |
R833370 (2009) R833370 (Final) |
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Liao H, Henze DK, Seinfeld JH, Wu S, Mickley LJ. Biogenic secondary organic aerosol over the United States: comparison of climatological simulations with observations. Journal of Geophysical Research--Atmospheres 2007;112(D6):D06201 (19 pp.). |
R833370 (2009) R833370 (Final) R830959 (Final) |
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Pye HOT, Liao H, Wu S, Mickley LJ, Jacob DJ, Henze DK, Seinfeld JH. Effect of changes in climate and emissions on future sulfate-nitrate-ammonium aerosol levels in the United States. Journal of Geophysical Research--Atmospheres 2009;114(D1):D01205 (18 pp.). |
R833370 (2008) R833370 (2009) R833370 (Final) R830959 (Final) |
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Pye HOT, Seinfeld JH. A global perspective on aerosol from low-volatility organic compounds. Atmospheric Chemistry and Physics 2010;10(9):4377-4401. |
R833370 (2009) R833370 (Final) R833749 (2010) R833749 (Final) |
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Streets DG, Zhang Q, Wu Y. Projections of global mercury emissions in 2050. Environmental Science & Technology 2009;43(8):2983-2988. |
R833370 (2008) R833370 (2009) R833370 (Final) |
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Tai APK, Mickley LJ, Jacob DJ. Correlations between fine particulate matter (PM2.5) and meteorological variables in the United States: implications for the sensitivity of PM2.5 to climate change. Atmospheric Environment 2010;44(32):3976-3984. |
R833370 (2009) R833370 (Final) |
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Wu S, Mickley LJ, Leibensperger EM, Jacob DJ, Rind D, Streets DG. Effects of 2000-2050 global change on ozone air quality in the United States. Journal of Geophysical Research--Atmospheres 2008;113(D6):D06302 (12 pp.). |
R833370 (2007) R833370 (2008) R833370 (2009) R833370 (Final) R830959 (Final) |
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Wu S, Mickley LJ, Jacob DJ, Rind D, Streets DG. Effects of 2000-2050 changes in climate and emissions on global tropospheric ozone and the policy-relevant background surface ozone in the United States. Journal of Geophysical Research--Atmospheres 2008;113(D18):D18312 (12 pp.). |
R833370 (2008) R833370 (2009) R833370 (Final) R830959 (Final) |
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Supplemental Keywords:
chemical transport, volatile organic compounds (VOCs), nitrogen oxides, sulfates, organics, pollution prevention, environmental chemistry, modeling, climate models, tropospheric ozone, tropospheric aerosol, mercury, mercury deposition, RFA, Scientific Discipline, Air, climate change, Air Pollution Effects, Environmental Monitoring, Ecology and Ecosystems, Atmosphere, air quality modeling, mercury deposition, Baysian analysis, climate models, atmospheric modelsRelevant Websites:
Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.