Grantee Research Project Results
2007 Progress Report: Study the Impact of Global Change on Air Quality Using the Global-Through-Urban Weather Research and Forecast Model with Chemistry
EPA Grant Number: R833376Title: Study the Impact of Global Change on Air Quality Using the Global-Through-Urban Weather Research and Forecast Model with Chemistry
Investigators: Zhang, Yang , Streets, David G. , Karamchandani, Prakash
Institution: North Carolina State University , Atmospheric and Environmental Research, Inc. , Argonne National Laboratory
Current Institution: North Carolina State University , Argonne National Laboratory , Atmospheric and Environmental Research, Inc.
EPA Project Officer: Chung, Serena
Project Period: May 7, 2007 through May 6, 2011 (Extended to May 6, 2012)
Project Period Covered by this Report: February 1, 2007 through January 31,2008
Project Amount: $900,000
RFA: Consequences of Global Change For Air Quality (2006) RFA Text | Recipients Lists
Research Category: Climate Change , Air
Objective:
The objectives of this project are to estimate the long-term impacts of global changes on urban and regional air quality over the next 50 years and provide a realistic assessment of those impacts and associated uncertainties using an advanced 3-D model and available observational datasets. We hypothesize that the two-way feedbacks between climate changes and air quality are important in quantifying the impact of global changes on air quality.
Progress Summary:
During year 1, we have accomplished several tasks in model development and applications that are critical to achieve our goals. Our major findings and their significances are summarized below.
- Simulations using various mechanism combinations from global and mesoscale WRF/Chem show that simulated O3 and PM2.5 concentrations are sensitive to gas-phase mechanisms and aerosol modules. Such differences will be reflected in simulated aerosol direct and indirect effects and have important implications in result interpretation.
- Preliminary model evaluation shows reasonably good agreement with observational data over the United States, with better agreement for surface predictions of O3 and PM2.5 and column CO and NO2 abundances, but larger biases for column variables such as TOR and AOD. These indicate a need to carefully choose upper boundary conditions to improve model performance aloft, which is important for global simulations.
- Results from G-WRF/Chem are overall consistent with those from the continental United States where extensive observational data are available, in terms of spatial varibilities, despite differences in magnitudes of absolute values. Such an intercomparison is valuable as it provides model fidelity over regions without extensive surface observational data for model evaluation (e.g., Asia).
- Box model simulations with the revised CB05 mechanism (i.e., CB05-G) for a variety of conditions illustrate the role of halogens such as chlorine and bromine on O3 and Hg species. Heterogeneous chemistry also plays an important role in O3 and Hg depletion events. For most conditions, oxidation by Br and BrO is generally the most important pathway for Hg(0) depletion. However, the lower stratospheric simulation shows that oxidation by other pathways, in particular by the OH radical, can become important under certain conditions. Inclusion of these reactions in CB05-G allows its applications over a global domain.
Future Activities:
The major foci for year 2 are model development, application, and evaluation. The objectives are to: (1) complete the proposed major model development tasks including expansion of the CB05 gas-phase mechanism, improvement of PM and aerosol-cloud interaction treatments, and implementation of a plume-in-grid treatment in WRF/Chem; (2) complete model simulations for current-year (2001) scenarios and model evaluation for year 2001; and (3) conduct model simulations under future climate/emission scenarios.
Journal Articles on this Report : 1 Displayed | Download in RIS Format
Other project views: | All 124 publications | 22 publications in selected types | All 20 journal articles |
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Type | Citation | ||
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Zhang Y. Online-coupled meteorology and chemistry models: history, current status, and outlook. Atmospheric Chemistry and Physics 2008;8(11):2895-2932. |
R833376 (2007) R833376 (Final) |
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Supplemental Keywords:
global-through-urban WRF/Chem, air quality modeling, climate modeling, coupled meteorology and air quality, aerosols, two-way feedbacks, two-way nesting, RFA, Air, climate change, Air Pollution Effects, Atmosphere, air quality modelingRelevant Websites:
http://www.meas.ncsu.edu/aqforecasting/ Exit
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.