2010 Progress Report: Ensemble Analyses of the Impact and Uncertainties of Global Change on Regional Air Quality in the U.S.

EPA Grant Number: R833369
Title: Ensemble Analyses of the Impact and Uncertainties of Global Change on Regional Air Quality in the U.S.
Investigators: Lamb, Brian , Guenther, Alex , Mass, Clifford , McKenzie, Donald , Salathe, Eric , Theobald, David M. , Wiedinmyer, Christine
Current Investigators: Lamb, Brian , Chung, Sandra , Guenther, Alex , Mass, Clifford , McKenzie, Donald , Salathe, Eric , Wiedinmyer, Christine
Institution: Washington State University , Colorado State University , National Center for Atmospheric Research , USDA Forest Service , University of Washington
Current Institution: Washington State University , National Center for Atmospheric Research , USDA Forest Service , University of Washington
EPA Project Officer: Hunt, Sherri
Project Period: February 1, 2007 through January 31, 2011 (Extended to January 31, 2012)
Project Period Covered by this Report: February 1, 2010 through January 31,2011
Project Amount: $899,987
RFA: Consequences of Global Change For Air Quality (2006) RFA Text |  Recipients Lists
Research Category: Global Climate Change , Climate Change , Air

Objective:

This project builds on results from a previous EPA global change project (RD8383096, Chen, et al., 2009a,b; Avise, et al., 2009). Our overall goal is to answer questions, as initially posed in our previous project, related to the effects of global change on continental and regional air quality and to include quantitative estimates of uncertainties as part of the answers to our research questions. We employ an ensemble modeling approach with three specific objectives: 1) to develop a quantitative measure of the uncertainty in our modeling framework using ensemble modeling methods in comparison to current 1995-2004 observations; 2) to project these uncertainties into the future for the period 2045-2054 and quantitatively address the uncertainties that accompany projections of future emissions, both global and U.S., including changes in landcover, urbanization, biogenic emissions, and fire emissions; and 3) to continue to address our research questions that will determine the consequences of global change upon U.S. air quality. For the latter objective, we employ an attribution method where individual simulations are used with a specific future condition (i.e., future chemical boundary conditions) while keeping other model components fixed with current conditions. In this way, the relative effects due to chemical boundary conditions, climate change, biogenic emissions, U.S. anthropogenic emissions, and fire emissions can be quantified.

Progress Summary:

Our approach is to use ECHAM-5 and CCSM3 global circulation model output to drive WRF continental simulations for the A1B and B1 Intergovernmental Panel on Climate Change (IPCC) scenarios. The CMAQ chemical transport model is applied at a partial hemispheric scale to account for the impact of global emissions upon chemical boundary conditions in the United States and then CMAQ is used with 36 km grid cells to simulate ozone, PM2.5 and related pollutants on an hourly basis for summertime conditions. Simulations have been completed for five representative summers during current (1995-2004) and future (2045-2054) decades. Details regarding the modeling framework and approach have been described in previous reports.

In this report, we present results in terms of daily maximum 8 hr ozone levels for the United States where we have used the ECHAM5 GCM output for the A1B scenario to drive the WRF meteorological model. Results for PM2.5 are under analysis and not discussed in this report. The attribution simulations show that overall for the A1B future case, the peak ozone (as represented by the 98th percentile by region) slightly increases in the west, but increases by more (up to 7 ppbv) in the central and eastern portion of the United States. These changes are the result of increases in ozone due to increasing chemical boundary conditions offset by decreases in ozone due to decreasing U.S. emissions and perturbed either up or down, depending on the region, by changes in climate, biogenic emissions, and land use. In the western United States, climatic effects (meteorology plus biogenic emissions) decrease, while these climatic effects are positive in other parts of the United States due to warmer temperatures and the associated effects on atmospheric reactions and biogenic emissions. Land use effects associated with expanded croplands tend to slightly offset the increases associated with climate effects alone.

To put these results in terms appropriate for policy use, we calculated a relative reduction factor (RRF) using current/future emission changes as typically done for SIP analyses and then further modified the RFF to account for climate effects (RRFclimate, future/current clmate). In all regions, except the Northwest and Southwest, climate change increases the regional average RRF, the peak RRF, and the spatial variability (represented by the standard deviation) of the RRF (i.e., RRFclimate > RRF). In the Southwest, the peak RRF and the spatial variability of the RRF both increase with future- climate conditions, while the average RRF is unchanged. In the South, Midwest, and Northeast, the increase in the average RRF due to climate change more than offsets the decrease in ozone achieved by the change in anthropogenic emissions (i.e., RRF is ≤ 1, while RRFclimate is ≥ 1). In other regions, the increase in RRF due to climate change does not completely offset the decrease in ozone achieved by the projected anthropogenic emissions changes, but it does reduce the effect those changes have on ozone (i.e., RRFclimate > RRF, and RRF < RRFclimate < 1). In all regions but the Northwest, the number of sites having an RRF > 1 greatly increases under the future climate, with nearly half (45%) of all sites having an RRFclimate > 1, compared to only 3% when climate change is not taken into account.

Future Activities:

We continue to run simulations to account for changes in fire emissions between current and future conditions and we will initiate shortly simulations driven with the CCSM3 global model output as well as cases for the B1 IPCC scenario. At the same time, we have begun simulations to calculate policy relevant background concentrations of ozone and PM2.5 for the United States. Three manuscripts are in preparation describing results from this research.


Journal Articles on this Report : 8 Displayed | Download in RIS Format

Other project views: All 16 publications 12 publications in selected types All 12 journal articles
Type Citation Project Document Sources
Journal Article Avise J, Chen J, Lamb B, Wiedinmyer C, Guenther A, Salathe E, Mass C. Attribution of projected changes in summertime US ozone and PM2.5 concentrations to global changes. Atmospheric Chemistry and Physics 2009;9(4):1111-1124. R833369 (2008)
R833369 (2009)
R833369 (2010)
R833369 (Final)
R830962 (Final)
  • Full-text: Atmospheric Chemistry and Physics-Full Text PDF
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  • Abstract: Atmospheric Chemistry and Physics-Abstract
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  • Journal Article Chen J, Avise J, Lamb B, Salathe E, Mass C, Guenther A, Wiedinmyer C, Lamarque J-F, O'Neill S, McKenzie D, Larkin N. The effects of global changes upon regional ozone pollution in the United States. Atmospheric Chemistry and Physics 2009;9(4):1125-1141. R833369 (2008)
    R833369 (2009)
    R833369 (2010)
    R833369 (Final)
    R830962 (Final)
  • Full-text: Atmospheric Chemistry and Physics-Full Text PDF
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  • Abstract: Atmospheric Chemistry and Physics-Abstract
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  • Journal Article Chen J, Avise J, Guenther A, Wiedinmyer C, Salathe E, Jackson RB, Lamb B. Future land use and land cover influences on regional biogenic emissions and air quality in the United States. Atmospheric Environment 2009;43(36):5771-5780. R833369 (2009)
    R833369 (2010)
    R833369 (Final)
    R830962 (Final)
  • Full-text: Science Direct-Full Text HTML
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  • Abstract: Science Direct-Abstract
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  • Other: Science Direct-Full Text PDF
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  • Journal Article Duliere V, Zhang Y, Salathe Jr. EP. Extreme precipitation and temperature over the U.S. Pacific Northwest:a comparison between observations, reanalysis data, and regional models. Journal of Climate 2011;24(7):1950-1964. R833369 (2009)
    R833369 (2010)
    R833369 (Final)
  • Full-text: University Corporation for Atmospheric Research-Full Text PDF
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  • Abstract: AMS-Abstract
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  • Other: AMS-Full Text PDF
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  • Journal Article Salathe Jr. EP, Leung LR, Qian Y, Zhang Y. Regional climate model projections for the State of Washington. Climatic Change 2010;102(1-2):51-75. R833369 (2009)
    R833369 (2010)
    R833369 (Final)
  • Full-text: SpringerLink-Full Text PDF
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  • Abstract: SpringerLink-Abstract
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  • Other: University of Washington-Full Text PDF
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  • Journal Article Salathe Jr. EP, Steed R, Mass CF, Zahn PH. A high-resolution climate model for the U.S. Pacific Northwest: mesoscale feedbacks and local responses to climate change. Journal of Climate 2008;21(21):5708-5726. R833369 (2009)
    R833369 (2010)
    R833369 (Final)
  • Full-text: AMS-Full Text HTML
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  • Abstract: AMS-Abstract
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  • Other: AMS-Full Text PDF
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  • Journal Article Zhang Y, Duliere V, Mote PW, Salathe Jr. EP. Evaluation of WRF and HadRM mesoscale climate simulations over the U.S. Pacific Northwest. Journal of Climate 2009;22(20):5511-5526. R833369 (2009)
    R833369 (2010)
    R833369 (Final)
  • Full-text: Journal of Climate-Full Text HTML
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  • Abstract: Journal of Climate-Abstract
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  • Other: Journal of Climate-Full Text PDF
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  • Journal Article Zhang Y, Qian Y, Duliere V, Salathe Jr. EP, Leung LR. ENSO anomalies over the Western United States: present and future patterns in regional climate simulations. Climatic Change 2012;110(1-2):315-346. R833369 (2009)
    R833369 (2010)
    R833369 (Final)
  • Full-text: University of Washington-Full Text PDF
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  • Abstract: SpringerLink-Abstract
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  • Supplemental Keywords:

    ozone, PM2.5 fire emissions, biogenic emissions, relative reduction factor, air quality management, RFA, Scientific Discipline, Air, climate change, Air Pollution Effects, Environmental Monitoring, Ecological Risk Assessment, Atmosphere, air quality modeling, global change, Baysian analysis, climate models, atmospheric models

    Progress and Final Reports:

    Original Abstract
  • 2007
  • 2008 Progress Report
  • 2009 Progress Report
  • Final Report