2006 Progress Report: Investigation of the Effects of Changing Climate on Fires and the Consequences for U.S. Air Quality, Using a Hierarchy of Chemistry and Climate Models

EPA Grant Number: R832275
Title: Investigation of the Effects of Changing Climate on Fires and the Consequences for U.S. Air Quality, Using a Hierarchy of Chemistry and Climate Models
Investigators: Logan, Jennifer A. , Byun, Daewon , Diner, David , Jacob, Daniel J. , Li, Qinbin , Mazzoni, Dominic M. , Mickley, Loretta J.
Institution: Harvard University , Jet Propulsion Laboratory - Pasadena , University of Houston
EPA Project Officer: Chung, Serena
Project Period: April 1, 2005 through March 31, 2008 (Extended to March 31, 2010)
Project Period Covered by this Report: April 1, 2006 through March 31, 2007
Project Amount: $750,000
RFA: Fire, Climate, and Air Quality (2004) RFA Text |  Recipients Lists
Research Category: Air Quality and Air Toxics , Global Climate Change , Climate Change , Air


This project is an assessment of the impacts of climate change on forest fires and ozone and particulate matter air quality in the United States from the present day till 2050. The project will explore the relationships between climate and frequency and intensity of forest fires in North America. Future climate predicted using a general circulation model (GCM) and relationships between fire and climate that we have developed will be used to predict future fires in the United States. The height of forest fire plumes over North America will be investigated using the MISR satellite data. Using global and regional scale chemistry-aerosol transport models we will investigate the role of future fires on air quality.

Progress Summary:

We derived emissions of organic carbon (OC) from forest fires in the western U.S. using data for area burned for 1980-2004 and ecosystem specific fuel loadings, and used these in the GEOS-Chem model to simulate OC for 1989-2004, the period with IMPROVE observations. Modeled and observed OC concentrations are highly correlated (R2= 0.88), with much less correlation if we use the same fire emissions each year (R2= 0.4). Using the year-by-year fire emissions, we find that the contribution of OC mass to the total fine aerosol concentration at the IMPROVE sites is ~40% in low fire years, but increases to ~55% in high fire years. We estimated that the observed increase in wildfire activity after the mid-1980s has caused mean OC concentrations in summer over the western U.S. to increase by 30% relative to 1970-1984 [Spracklen et al., 2007].

We explored relationships between area burned and climate in the western U.S. and Alaska and developed regressions for forested ecosystems of the Western U.S. that explain 50-60% of the variance in annual area burned. We used meteorological fields from the GISS Model III combined with the area burned regressions to predict how area burned will evolve in 2000-2050. The GCM projects that U.S. summertime temperatures increase by as much as 2-3 K, while precipitation rates will stay roughly the same. Using the GISS meteorology, our fire prediction scheme calculates large (50-90%) increases in area burned in forest ecosystems across the western U.S. Applying the predicted areas burned to an aerosol-only version of the GEOS-Chem model, we simulate future changes in carbonaceous aerosol. We find that summertime mean OC concentrations over the western United States increase by as much as 50% in some regions as a result of the trend in area burned [Spracklen et al., in preparation].

The paper describing the 77 fire plumes identified in MISR data by the original technique has been published [Mazzoni et al., 2007]. The median plume height is 2.2 km, with a range of 0.7-5.2 km. We found that the original automatic approach misses many plumes, and developed a new tool that relies on a person to digitize each plume; subsequent extraction of MISR data is automated. The new MISRTool was applied to the 2004 wild fire season in North America, and 585 plumes were found.

We performed test CMAQ simulations using the GISS meteorology, downscaled in two steps: GISS (5° x 4°)108-km MM536-km MM5 using four-dimensional data assimilation. As the predicted areas burned were yet not available, we used fire statistics derived from satellite data for the test runs. Chemistry boundary conditions for CMAQ were prepared from 2002 GEOS-Chem output.

Future Activities:

Using meteorological fields provided by the GCM and the area burned prediction schemes we have developed, we will extend our 5-year wildfire aerosol simulations with the GISS GCM to 10-year tracer simulations. We will complete our predictions of area burned for Canada and Alaska from 2000 to 2050, so that they can be included in the aerosol runs. We will analyze the new MISR database, and relate smoke plume heights to fire characteristics and meteorology. We will perform 5-year GEOS-Chem full chemistry simulations with GCM input, and peerform and analyze CMAQ simulations for the present day and future, using one typical present-day year and one typical future year. Finally, we will compare aerosol forcing due to 1998 wildfires relative to the forcing from other recent years (Harvard).

Journal Articles on this Report : 2 Displayed | Download in RIS Format

Other project views: All 14 publications 5 publications in selected types All 5 journal articles
Type Citation Project Document Sources
Journal Article Mazzoni D, Logan JA, Diner D, Kahn R, Tong L, Li Q. A data-mining approach to associating MISR smoke plume heights with MODIS fire measurements. Remote Sensing of Environment 2007;107(1-2):138-148. R832275 (2006)
R832275 (2007)
R832275 (2008)
R832275 (Final)
  • Full-text: ScienceDirect-HTML
  • Abstract: ScienceDirect-Abstract
  • Other: ScienceDirect-PDF
  • Journal Article Spracklen D, Logan JA, Mickley LJ, Park RJ, Yevich R, Westerling AL, Jaffe DA. Wildfires drive interannual variability of organic carbon aerosol in the western U.S. in summer. Geophysical Research Letters 2007;34:L16816, doi:10.0129/2007GL030037. R832275 (2006)
    R832275 (2007)
    R832275 (2008)
    R832275 (Final)
  • Full-text: University of California, Merced-Full Text PDF
  • Abstract: American Geophysical Union-Abstract
  • Supplemental Keywords:

    forest fires, fire emissions, biomass burning, air quality, tropospheric ozone, tropospheric aerosol, PM, visibility, climate models, air pollution, climate change, downscaling,, RFA, Scientific Discipline, Air, Ecosystem Protection/Environmental Exposure & Risk, Aquatic Ecosystems & Estuarine Research, Environmental Chemistry, climate change, Air Pollution Effects, Aquatic Ecosystem, Monitoring/Modeling, Environmental Monitoring, Ecological Risk Assessment, Atmosphere, anthropogenic stress, environmental measurement, meteorology, climatic influence, global ciruclation model, ozone depletion, tidal marsh, socioeconomics, ecosystem indicators, climate models, aquatic ecosystems, environmental stress, coastal ecosystems, global climate models, climate model, ecosystem stress, forest resources, ecological models, sea level rise, air quality, atmospheric chemistry, climate variability

    Relevant Websites:

    Information on this project may be found at http://www-as.harvard.edu/chemistry/trop/curresh.html#wildfires Exit and http://www.imaqs.uh.edu Exit .

    Progress and Final Reports:

    Original Abstract
  • 2005 Progress Report
  • 2007 Progress Report
  • 2008 Progress Report
  • Final Report