Combustion efficiency observed with CO and NO2 TROPOMI data: a first
counties scale study during the 2020 fires of California
Abstract
The 2020 California fire season yielded the largest fires in California
history. TROPOMI nitrogen dioxide (NO2) and carbon monoxide (CO) ratios
(i.e. mole density ratios; MDR) have been previously used to distinguish
fire combustion among different vegetation types around the world. Here,
we analyze the MDR from TROPOMI overpasses to identify fire
characteristics over two regions of California where two wildfires were
reported. We show that MDR calculated with TROPOMI NO2 and CO columns
can be used to assess fire characteristics at the scale of counties
through identifying the smoldering fires of the northern region and
flaming fire of the southern region with a shift in the combustion at
the end of September resulting from a change in fuel types. Improvement
in the land cover maps and use of hourly data could help to better
attribute MDR to specific fuel source categories.