2 research outputs found
Quantifying O<sub>3</sub> Impacts in Urban Areas Due to Wildfires Using a Generalized Additive Model
Wildfires
emit O<sub>3</sub> precursors but there are large variations
in emissions, plume heights, and photochemical processing. These factors
make it challenging to model O<sub>3</sub> production from wildfires
using Eulerian models. Here we describe a statistical approach to
characterize the maximum daily 8-h average O<sub>3</sub> (MDA8) for
8 cities in the U.S. for typical, nonfire, conditions. The statistical
model represents between 35% and 81% of the variance in MDA8 for each
city. We then examine the residual from the model under conditions
with elevated particulate matter (PM) and satellite observed smoke
(“smoke days”). For these days, the residuals are elevated
by an average of 3–8 ppb (MDA8) compared to nonsmoke days.
We found that while smoke days are only 4.1% of all days (May–Sept)
they are 19% of days with an MDA8 greater than 75 ppb. We also show
that a published method that does not account for transport patterns
gives rise to large overestimates in the amount of O<sub>3</sub> from
fires, particularly for coastal cities. Finally, we apply this method
to a case study from August 2015, and show that the method gives results
that are directly applicable to the EPA guidance on excluding data
due to an uncontrollable source
Biomass Burning Smoke Climatology of the United States: Implications for Particulate Matter Air Quality
We
utilize the NOAA Hazard Mapping System smoke product for the
period of 2005 to 2016 to develop climatology of smoke occurrence
over the Continental United States (CONUS) region and to study the
impact of wildland fires on particulate matter air quality at the
surface. Our results indicate that smoke is most frequently found
over the Great Plains and western states during the summer months.
Other hotspots of smoke occurrence are found over state and national
parks in the southeast during winter and spring, in the Gulf of Mexico
southwards of the Texas and Louisiana coastline during spring season
and along the Mississippi River Delta during the fall season. A substantial
portion (20%) of the 24 h federal standard for particulate pollution
exceedance events in the CONUS region occur when smoke is present.
If the U.S. Environmental Protection Agency regulations continue to
reduce anthropogenic emissions, wildland fire emissions will become
the major contributor to particulate pollution and exceedance events.
In this context, we show that HMS smoke product is a valuable tool
for analysis of exceptional events caused by wildland fires and our
results indicate that these tools can be valuable for policy and decision
makers