Grantee Research Project Results
2003 Progress Report: Impacts of Climate Change and Global Emissions on US Air Quality: Development of an Integrated Modeling Framework and Sensitivity Assessment
EPA Grant Number: R830961Title: Impacts of Climate Change and Global Emissions on US Air Quality: Development of an Integrated Modeling Framework and Sensitivity Assessment
Investigators: Adams, Peter , Pandis, Spyros N.
Institution: Carnegie Mellon University
EPA Project Officer: Chung, Serena
Project Period: March 23, 2003 through March 22, 2006 (Extended to March 22, 2007)
Project Period Covered by this Report: March 23, 2003 through March 22, 2004
Project Amount: $900,000
RFA: Assessing the Consequences of Global Change for Air Quality: Sensitivity of U.S. Air Quality to Climate Change and Future Global Impacts (2002) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Air , Climate Change
Objective:
The objectives of this research project are to:
1. Develop a comprehensive modeling system for the description of the interactions between climate and local/regional air quality. This system will use a global climate-chemistry model, a regional meteorological model, and a regional air quality model to describe the relevant time scales (hours to decades) and length scales (kilometers to global scales). It also will include an emissions processing system that will estimate climate-dependent emissions.
2. Determine the sensitivity of ozone, particulate matter (PM), acid deposition, and visibility to individual meteorological parameters by performing a set of sensitivity experiments in the context of regional chemical transport models (the PM Comprehensive Air Quality Model With Extensions [PMCAMx] and the Community Multiscale Air Quality Model [CMAQ]).
3. Evaluate the ability of the modeling system to describe current air quality in the United States, including annual average pollutant concentrations, their probability distributions, and the frequency of extreme air pollution episodes.
4. Develop a set of future (year 2050) scenarios (meteorological fields, emissions, and chemical boundary conditions). These scenarios will include climate change and/or global emissions changes and will bound the space of system responses (best, mean, and worst case scenarios).
5. Use the comprehensive modeling system and these scenarios to assess air quality in the year 2050, with and without climate changes and with and without changes in global emissions.
6. Investigate reduced form models and methodologies for incorporating the effects of climate change and global emission changes in future planning and assessment.
Progress Summary:
Currently, we are working towards each of the six objectives along three parallel fronts: (1) regional air quality modeling using the PMCAMx; (2) regional meteorological modeling with the Mesoscale Model 5 (MM5); and (3) global air quality and climate modeling with the Goddard Institute for Space Studies (GISS) General Circulation Model (GCM) and online chemistry.
Our current regional air quality modeling activities are focused on the second and third objectives. We are using data collected from the eastern PM Supersites to evaluate the ability of the PMCAMx to capture the behavior of PM in the Eastern United States, where little previous work has been done. Results for July 2001 and January 2002, generally show very good model performance. An important uncertainty, however, is the effect of nighttime nitrogen chemistry on nitrate aerosol levels. This uncertainty will be explored in future work. In addition, a series of sensitivity scenarios is being performed to determine the sensitivity of ozone and PM to changes in temperature, wind speed, and humidity. Other meteorological parameters will be addressed in future runs. A 4-day July 2001 simulation shows domain-average increases in ozone of 0.3 ppb/K and peak changes in ozone of 2.5 ppb/K. On the other hand, there are decreased concentrations of PM2.5, as higher temperatures do not favor ammonium nitrate aerosol formation. These and other sensitivity results are useful for understanding the main physical and chemical linkages between climate and air quality and will be used later in the project to understand the response of the fully coupled modeling system to simultaneous changes in several meteorological parameters.
Regional meteorological modeling activities use the MM5 to downscale climate fields from the GISS GCM. We are building on previous downscaling work performed by Barry Lynn on a separate U.S. Environmental Protection Agency-funded project. The previous work showed the sensitivity of downscaled meteorological fields to the selection of cloud physics in the MM5. In particular, the diurnal timing of precipitation has a significant impact on predicted temperatures, with nighttime precipitation favoring warmer temperatures. It also showed that the Grell parameterization better reproduced current average temperature and precipitation than the Betts-Miller parameterization. Our current work investigates how well each parameterization captures interannual variability in precipitation and temperature. The ability to predict the frequency of extremely high temperatures is important to this work, as these are linked to episodes of poor air quality. This work primarily addresses the first objective mentioned above.
Finally, we are pursuing global climate and chemistry modeling aimed at developing the future scenarios mentioned in the fourth objective. In these simulations, the atmospheric GISS GCM is forced with future (year 2050) sea surface temperatures. The future climate (global mean temperature increase as well as changes in circulation, cloudiness, humidity, and vertical mixing) predicted by the GCM is being evaluated to understand how our future scenarios compare to other GCMs and the implications this will have for our air quality simulations. In addition, the global model has online PM and ozone chemistry, and we are evaluating the response of these constituents (average and episodes) to future climate change.
Future Activities:
We will proceed along the schedule outlined in the future proposal. In particular, the current activities described above will be completed. Furthermore, the development of the comprehensive modeling system will be performed by coupling the GISS GCM, MM5, and PMCAMx models. Once the coupled modeling system is in place, our focus will be on the fifth objective, which is to use this modeling system to evaluate impacts of global emissions and climate change on U.S. air quality. Manuscripts describing the comparisons of the PMCAMx with eastern Supersites data and interannual variability of downscaled meteorology have been prepared and will be submitted for publication.
Journal Articles:
No journal articles submitted with this report: View all 9 publications for this projectSupplemental Keywords:
ambient air, atmosphere, ozone, particulates, visibility, acid deposition, global climate, tropospheric, chemical transport, oxidants, nitrogen oxides, sulfates, organics, modeling, general circulation models, GCMs, climate models, particulate matter, PM, comprehensive modeling system,, RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, particulate matter, Air Quality, Air Pollutants, climate change, Air Pollution Effects, Chemistry, Monitoring/Modeling, Environmental Monitoring, Atmospheric Sciences, Atmosphere, anthropogenic stress, aerosol formation, ambient aerosol, atmospheric particulate matter, atmospheric dispersion models, ecosystem models, environmental measurement, meteorology, climatic influence, emissions monitoring, global change, ozone, air quality models, climate, modeling, climate models, greenhouse gases, airborne aerosols, atmospheric aerosol particles, atmospheric transport, neural networks, environmental stress, regional emissions model, ecological models, climate model, greenhouse gas, aerosols, atmospheric models, Global Climate Change, atmospheric chemistry, ambient air pollutionRelevant Websites:
http://www.ce.cmu.edu/~adams/index.html Exit
http://www.cheme.cmu.edu/who/faculty/pandis.html 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.