2017 Progress Report: Planning for an Unknown Future: Incorporating Meteorological Uncertainty into Predictions of the Impact of Fires and Dust on US Particulate Matter

EPA Grant Number: R835884
Title: Planning for an Unknown Future: Incorporating Meteorological Uncertainty into Predictions of the Impact of Fires and Dust on US Particulate Matter
Investigators: Fischer, Emily , Barnes, Elizabeth , Pierce, Jeffrey
Institution: Colorado State University
EPA Project Officer: Chung, Serena
Project Period: January 1, 2016 through December 31, 2018 (Extended to December 31, 2019)
Project Period Covered by this Report: January 1, 2017 through December 31,2017
Project Amount: $349,969
RFA: Particulate Matter and Related Pollutants in a Changing World (2014) RFA Text |  Recipients Lists
Research Category: Air , Climate Change


The objective of this research is to determine how model uncertainty in future meteorology translates into uncertainty in the contributions of smoke and dust to future particulate matter (PM) episodes.

Progress Summary:

Using the National Environmental Satellite, Data, and Information Service (NESDIS) Hazard Mapping System (HMS) smoke data for North America for the period 2007 to 2014, we examined a subset of fires that are confirmed to have produced sufficient smoke to warrant the initiation of a U.S. National Weather Service smoke forecast. Brey et al. (2018) moves a new data set from a daily operational setting to a research context, and it demonstrates how changes to the frequency or intensity of fires in the western United States could impact the frequency of smoke over other EPA regions.

We also have investigated the interannual variability of human-ignited and lightning-ignited wildfire burn area, and whether they share relationships with environmental variables such as mean summer temperature and total precipitation. We use the Fire Program Analysis Wildfire Occurrence Data (FPA FOD) and the ERA-Interim reanalysis data from the European Centre for Medium-Range Weather Forecasts (ECMWF) to explore these questions focusing on three ecoregions in the western United States. These data show that, on average, human-ignited wildfires are smaller than lightning-ignited wildfires. The two ecoregions that account for the majority of the western U.S. burn area (and large fires) are the Western Cordillera (~forested mountain areas, high emission factors) and the Cold Deserts (~Great Basin, low emission factors). In both of these ecoregions, total burn area is dominated by lightning-ignited wildfires. The interannual variability of the summertime burn area for both types of ignitions are well correlated with each other. In the cold deserts and forested mountains, mean summer temperature and total precipitation explain less of the observed variability in human-ignited wildfire burn area than lightning-ignited wildfire burn area. By contrast, in the densely populated Mediterranean California ecoregion, over 80% of the total wildfire burn area is due to human-ignited wildfires, but the interannual variability in burn area for both types of ignitions are poorly correlated (r < 0.37) with temperature and precipitation. Previous studies have shown that human-ignited wildfires occur on days and locations with significantly higher fuel moisture content than the days and locations lightning-ignited wildfires occur. After accounting for ecoregion and season, we observe that human-ignited wildfires expand the elevation, time of year, and fuel moisture content values where wildfires occur, however this expansion is most meaningful for wildfires less than 1,000 acres in size and wildfires less than 1,000 acres account for less than 15% of the total burn area in the western United States.

Future Activities:

Our two goals for Year 3 of the project are to (1) examine the present day environmental drivers of dust emissions in the western United States, and (2) quantify the spread in future meteorological drivers of dust and smoke emissions as diagnosed by the suite of CMIP5 climate models. As we have focused primarily on the relationships between PM emissions and meteorology at this point, we plan to refocus on concentrations where possible.

Journal Articles on this Report : 1 Displayed | Download in RIS Format

Other project views: All 4 publications 1 publications in selected types All 1 journal articles
Type Citation Project Document Sources
Journal Article Brey SJ, Ruminski M, Atwood SA, Fischer EV. Connecting smoke plumes to sources using Hazard Mapping System (HMS) smoke and fire location data over North America. Atmospheric Chemistry and Physics 2018;18(3):1745-1761. R835884 (2017)
  • Full-text: ACP-PDF
  • Abstract: ACP-Abstract
  • Supplemental Keywords:

    Particulate matter, fires, dust, climate, synoptic meteorology

    Progress and Final Reports:

    Original Abstract
  • 2016 Progress Report
  • 2018