US Trends in Wildfire Smoke derived from NOAA's Hazard Mapping System
Smoke Product and Airport Data from 2010-2020
Abstract
The scale of wildfires and their associated smoke plumes have increased
in the last four decades and have exacerbated the health risks for
people living within wildfire-prone areas. While satellite imagery
enables us to monitor the location, abundance, and severity of smoke,
datasets such as NOAA’s Hazard Mapping System (HMS) smoke product are
unvalidated and may not reflect ground-level smoke conditions. We
propose that airports monitoring the presence of smoke may offer a
localized constraint on satellite smoke products. Our research aims to
validate NOAA’s HMS product by comparing how well the HMS smoke data
agree with NOAA’s Integrated Surface Database (ISD) of local, hourly
airport data from 2010 to 2020 across the US. Our spatial and temporal
analysis shows that the trend in the number of smoke days is similar
between the two datasets. HMS smoke plumes are qualitatively categorized
into 3 densities: light, medium, and heavy. Particularly, HMS smoke
plumes with “medium or heavy” densities have the strongest correlation
of r = 0.60 and a mean absolute error of 0.73. We observe the greatest
difference in the airport and HMS-derived mean smoke days across the
west and east coast, especially in California’s Central Valley and
eastern Washington. However, there is a very weak correlation of r =
0.17 between surface-level mean smoke days and from HMS “heavy, medium,
or light” density smoke days. Further, using all HMS smoke densities
tend to overestimate the trends in and magnitude of smoke days. Based on
these results, NOAA’s HMS product is somewhat consistent with trends
observed at airports, but caution should be used in assuming equivalence
with surface conditions in research investigating wildfire smoke and its
consequences for public health.