2016 Progress Report: Planning for an Unknown Future: Incorporating Meteorological Uncertainty into Predictions of the Impact of Fires and Dust on US Particulate MatterEPA 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
Project Period Covered by this Report: January 1, 2016 through December 31,2016
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.
In Year 1, we used the National Environmental Satellite, Data and Information Service (NESDIS) Hazard Mapping System (HMS) smoke data for North America for 2007 to 2014 to examine the subset of fires that are confirmed to have produced sufficient smoke to warrant the initiation of a U.S. National Weather Service (NWS) smoke-related air quality forecast. We defined smoke hours, a quantity designed to be proportional to total column smoke, by linking observed smoke plumes to observed fires using HYSPLIT trajectories. This portion of the Year 1 analysis shows that the Southwest, Northwest and Northwest Territories trigger the most air quality forecasts, and produce more smoke than any other North American region by measure of the number of points analyzed, the duration of those fires, and the total number of smoke hours produced. This data set confirms that there is a substantial amount of smoke-producing fire activity in the Southeast, particularly along the lower Mississippi River Valley. We have also produced a smoke transport climatology for the summer wildfire season. Based on our metric of smoke hours, the U.S. regions that produce the most smoke are the Northwest, Southwest and Rocky Mountains. Heavily populated locations in the eastern United States (Northeast, Mid Atlantic, Southeast) are routinely impacted by wildland fire smoke from western regions. Thus, changes to the frequency or intensity of fires in the United States west or Canada will likely impact the entire U.S. airshed. This portion of the Year 1 analysis led to two conference presentations.
In Year 1, we also acquired model output from a single coupled land-atmosphere-climate model (Community Earth System Model; CESM) and focused on analyzing relationships between meteorological parameters and the emissions of PM (black carbon and organic carbon) from wildfires. We focused on identifying the relationships between PM emissions from fires and (1) high-wind days, (2) precipitation days, (3) high-temperature days, and (4) stagnation events. The regions that account for the largest direct emissions of aerosol species in the Community Land Model (CLM) include the Coastal, Sierra Nevada, Cascade and Rocky Mountain ranges. There is a different spatial distribution for each of the meteorological events, and some conditions occur much more frequently than others. We have examined the conditional probability for PM emissions from fires when individual meteorological conditions are met. Of the meteorological conditions tested, high-temperature days, and days without significant precipitation, are associated with the highest emissions.
The goal of Year 1 is to quantify the relationship between meteorology and wildfire/dust aerosol concentrations, as we have focused primarily on the relationships between PM emissions and meteorology up to this point. Further analysis in Year 2 will be focused on understanding the relationships present in the CESM model output, and how well the present-day CESM simulation matches independent measures of smoke-production and transport. We plan to address dust in addition to smoke in the latter part of Year 2.