Grantee Research Project Results

2008 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: R833376
Title: 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: May 7, 2008 through May 6,2009
Project Amount: $900,000
RFA: Consequences of Global Change For Air Quality (2006) RFA Text | Recipients Lists
Research Category: Air , Climate Change

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 2, we have accomplished most tasks in model development and some model applications and evaluation that are critical to achieve our goals. Our major findings and their significances are summarized below.

The box model study with the updated CB05_GE mechanism, aqueous-phase chemistry and PM chemistry and dynamics treatment shows the importance of both heterogeneous and aqueous-phase chemistry to sulfate and nitrate formation with the aqueous-phase chemistry pathway dominating for SO2 conversion. These results are consistent with expectations and previous studies that have investigated the formation of sulfate in clouds (e.g., Seigneur and Saxena, 1988; Karamchandani and Venkatram, 1992). The results also indicate the importance of aqueous-phase chemistry in influencing the conversion of elemental mercury to RGM and viceversa. A significant amount of RGM is adsorbed to the particle phase when particle loadings are high.
Preliminary model evaluation for GU-WRF/Chem predictions show reasonably good agreement with near-surface temperature, water vapors, and shortwave radiation from either reanalysis dataset or satellite dataset, but larger bias in precipitation. It also shows a very good agreement with observed surface O3 and PM2.5 concentrations and reasonably good column CO and NO2 abundances, TOR, and AOD, as well as some cloud-related properties such as cloud fractions and CCN.
GU-WRF/Chem results show that aerosols can have various direct, semi-direct, and indirect effects on PBL meteorology and cloud/precipitation formation. For example, they can decrease shortwave radiation, near-surface temperature, and NO2 photolysis, PBL heights. They also contribute to the formation of CCN and increase cloud droplet number concentrations. These results will have important implications to the air quality-climate change interactions under current and future climate/emission scenarios.

Future Activities:

The major foci for year 2 are model application and evaluation. The objectives are (1) to complete the proposed major model development task on the implementation of a plumein-grid treatment in WRF/Chem; and (2) to complete model simulations and evaluation for current-year (2001) scenarios, and (3) to conduct model simulations under future climate/emission scenarios.

Journal Articles:

No journal articles submitted with this report: View all 124 publications for this project

Supplemental Keywords:

global-through-urban WRF/Chem, air quality modeling, climate modeling, coupled meteorology and air quality, aerosols, air quality-climate change feedbacks,, RFA, Air, Atmosphere, Air Pollution Effects, climate change, air quality modeling

Relevant Websites:

The research and resulted publications are disseminated via the web site of Zhang’s group at
http://www.meas.ncsu.edu/aqforecasting/

Progress and Final Reports:

Original Abstract

The 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.