Grantee Research Project Results
2011 Progress Report: Investigation of the Effects of Changing Climate on Fires and the Consequences for U.S. Air Quality, Phase 2.
EPA Grant Number: R834282Title: Investigation of the Effects of Changing Climate on Fires and the Consequences for U.S. Air Quality, Phase 2.
Investigators: Logan, Jennifer A. , Mickley, Loretta J. , Rind, David
Institution: Harvard University , NASA Goddard Institute for Space Studies
EPA Project Officer: Chung, Serena
Project Period: November 1, 2009 through October 31, 2012 (Extended to October 31, 2013)
Project Period Covered by this Report: November 1, 2010 through October 31,2011
Project Amount: $599,366
RFA: Adaptation for Future Air Quality Analysis and Decision Support Tools in Light of Global Change Impacts and Mitigation (2008) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , Climate Change , Air
Objective:
We will improve the prediction tools of wildfire activity over the western U.S. by taking
into account new and critical factors. To reduce uncertainties in our predictions, we will
perform ensemble projections for future wildfire activity with new fire models driven by
data from multiple scenarios and climate models. We will then apply the calculated fire
emissions to the chemistry-aerosol transport model GEOS-Chem to estimate the fireinduced
changes in carbonaceous (black carbon and organic carbon) aerosol
concentrations. For these simulations we will drive GEOS-Chem with meteorological
fields archived from the GISS GCM3.
As a part of this project, we make an effort to predict future wildfire activity in Southern
California at the midcentury, following our work that predicts future wildfire over the
western United States carried out in the last year. We compiled new gridded area burned
data on 0.5°×0.5° grids for Southern California during 1980-2009 based on the
interagency fire reports. We improve the prediction tools of wildfire activity over
Southern California by taking into account local geographic factors (e.g. topography,
population, and fuel load) and the Santa Ana wind (SAW). We apply these fire models
with simulated meteorological variables under the IPCC A1B scenario from 14 climate
models to project future area burned in Southern California. We use the median results
from these GCMs with a purpose to reduce the uncertainties from individual models.
Progress Summary:
We developed both regression models and a parameterization model for fire prediction
over the western U.S. The regression models build relationships between area burned and
meteorological factors with stepwise regression method based on ecoregions; they
explain 25%-60% of the variance in area burned over six ecoregions. The
parameterization model determines daily area burned over each grid point by an
empirical function composed of temperature, relative humidity, and precipitation. We use
simulated present-day and future daily meteorological variables under the A1B scenario
from 14 IPCC models and the NASA/GISS GCM3 to drive both fire models. Regression
models project that the annual area burned will increase by 25%-125% and
parameterization models by (35%-169%) over six ecoregions; both fire models predict a
significant increase in area burned over forest ecoregions. The length of fire season will
extend by three weeks for the warmer and drier climate. With the GEOS-Chem model,
we estimate that the average surface concentrations of organic carbon aerosol in summer
over the western United States will increase by 46%-70% and black carbon will increase
by 20-27% at midcentury, due to the increased wildfire emission. This work will be
submitted for publication by spring 2012.
In the above work, California was treated as one region, and our approaches for
predicting wildfires were least successful there. In Year 2, we focused on improving the
predictions for California. We compiled new gridded area burned data on a grid of
0.5°×0.5° for southern California during 1980-2009 based on over 55000 fire reports
from the Fire and Aviation Management Web Applications (FAMWEB). With the new
area burned data, we developed and evaluated both the regression and parameterization
models for three sub-regions in southern California. The regression fits, which use sitebased
meteorological variables from the FAMWEB, explain 40-46% of the variance in
area burned over three sub-regions, a large improvement over our previous result, 25%.
The parameterization is driven with the North American Regional Reanalysis (NARR) on
0.5°×0.5° grids. We improve the parameterization approach over southern California by
taking into account local geographic factors (e.g. topography, population, and fuel load)
and Santa Ana wind events. It is most successful in southwest California, explaining 64%
of the variance in area burned. In addition, the model captures well the seasonality of
wildfires in the three regions. Projections with the parameterization show that 7 out of 14
GCMs successfully capture the maximum area burned in October induced by Santa Ana
events in southwest California during 1981-2000. With these 7 GCMs, the regression
models projected median increases of 103%, 22%, and 32% in area burned over three
regions by the midcentury. With the parameterization, the projections show median
increases of 43% and 46% in southwest California and the Sierra Nevada. The
seasonality of area burned also shows some changes, with possible increases of the area
burned in September and October and more large fires in November by midcentury.
Future Activities:
Work is ongoing to extend our fire prediction model to include the
boreal forest fires of Canada. We will compile new gridded area burned data for North
America from 1980 to 2009. We will estimate future wildfire activity in North America
with ensemble projection method using different scenarios from multi-models. We will
improve calculations of the impact of changing fire activity on air quality using
meteorological fields with finer vertical and horizontal resolution.
Journal Articles:
No journal articles submitted with this report: View all 6 publications for this projectSupplemental Keywords:
shrub fires, fire emissions, Southern California, Santa Ana wind, elevation, population, fuel load, fire report, air pollution, parameterization
, RFA, Scientific Discipline, Air, climate change, Air Pollution Effects, Environmental Monitoring
Relevant Websites:
Information on this project may be found at
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.