Abstract.
This
study
reports
the
contribution
of
fire
emissions
on
ozone
(O₃)
pollution
in
Arizona
compared
to
local
and
regional
anthropogenic
emissions.
Using
WRF-Chem
modeling
system
with
different
O₃
CO
tags,
we
quantified
contributions
these
levels
during
June
2021,
a
period
when
region
was
experiencing
both
drought
conditions
extreme
heat.
Our
findings
indicate
that
background
accounted
for
about
50
%
total
O₃,
contributing
between
24
40
%.
During
peak
smoky
time
period,
fire-contributed
significant
across
Phoenix
metropolitan
area,
ranging
from
5
23
ppb
or
21
levels,
an
average
15
We
verify
tags
by
conducting
model
sensitivity
test
excluded
emissions,
which
showed
strong
agreement
spatiotemporal
pattern
due
although
magnitude
is
underestimated
factor
1.4.
further
demonstrates
wildfires
exacerbate
exceedances
over
urban
areas.
analysis
also
Yuma
are
significantly
influenced
transboundary
California
Mexico,
whereas
Phoenix's
mainly
driven
much
smaller
external
sources
period.
Consistent
previous
reports,
our
highlight
role
confounding
assessment
environments,
especially
dry
extremely
hot
summer
semi-arid/arid
regions.
Journal of Geophysical Research Atmospheres,
Journal Year:
2025,
Volume and Issue:
130(2)
Published: Jan. 15, 2025
Abstract
Inorganic
nitrate
(NO
3
−
),
a
crucial
component
of
fine
particulate
matter
(PM
2.5
has
not
shown
consistent
decrease,
despite
an
obvious
decrease
nitrogen
oxide
(NOx)
and
PM
.
The
atmospheric
oxidation
process
for
formation
been
deemed
key
factor
in
pollution;
however,
the
changes
sources
pathways
during
particular
haze
episode
require
further
investigation.
Here,
daily
dual
isotopes
(δ
15
N
δ
18
O)
were
used
to
quantify
Qingdao,
port
city
Northern
China,
from
September
2017
February
2018.
This
study
also
includes
detailed
introduction
two
episodes.
O
results
show
that
both
fractions
nocturnal
NOx
coal
combustion
lower
warmer
season
higher
colder
season.
increased
with
increasing
under
low
concentration
while
significantly
changed
concentration,
dominated
by
(70.6%
±
9.7%)
(66.1%
18.2%),
respectively.
1
was
attributed
smoke
transported
over
long
distances,
which
provided
large
amount
aerosol
particles
absorb
more
locally
formed
gaseous
HNO
or
2
5
In
this
episode,
meteorological
air
quality
factors,
sources,
mechanism
did
obviously
change.
Haze
caused
unfavorable
factors
enhanced
local
accumulation.
As
pollution
worsened,
pathway
shifted
OH
hydrolysis,
primary
source
vehicle
exhaust.
Geophysical Research Letters,
Journal Year:
2024,
Volume and Issue:
51(22)
Published: Nov. 26, 2024
Abstract
During
summer
2023
Canada
experienced
its
most
intense
wildfire
season
on
record.
Smoke
plumes
from
these
fires
advected
across
the
United
States
(U.S.)
Upper
Midwest,
producing
regional
scale
surface
enhancements
of
PM
2.5
and
ozone,
as
recorded
by
U.S.
monitoring
network.
These
events
are
notable
because
they
occurred
early
in
fire
(May
15‐June
30),
produced
highest
regional‐scale
ozone
levels
ever
northern
tier
during
(May–June)
or
late
(July‐August)
summer.
Specifically,
Midwest
50th
percentile
was
greater
than
any
other
year
since
1995,
when
network
had
sufficient
coverage
to
assess
levels;
90th
2002.
Satellite
aircraft
measurements
demonstrate
availability
precursors
production
within
smoke
plumes.
Atmospheric measurement techniques,
Journal Year:
2025,
Volume and Issue:
18(7), P. 1561 - 1589
Published: April 3, 2025
Abstract.
The
TROPOspheric
Monitoring
Instrument
(TROPOMI),
aboard
the
Sentinel-5
Precursor
(S5P)
satellite
launched
in
October
2017,
is
dedicated
to
monitoring
atmospheric
composition
associated
with
air
quality
and
climate
change.
This
paper
presents
global
retrieval
of
TROPOMI
tropospheric
formaldehyde
(HCHO)
nitrogen
dioxide
(NO2)
vertical
columns
using
an
updated
version
Peking
University
OMI
NO2
(POMINO)
algorithm,
which
focuses
on
improving
calculation
mass
factors
(AMFs).
algorithm
features
explicit
corrections
for
surface
reflectance
anisotropy
aerosol
optical
effects,
it
uses
daily
high-resolution
(0.25°×0.25°)
a
priori
HCHO
profiles
from
Global
Earth
Observing
System
Composition
Forecast
(GEOS-CF)
dataset.
For
cloud
correction,
consistent
approach
used
both
retrievals,
where
(1)
fraction
recalculated
at
440
nm
same
ancillary
parameters
as
those
AMF
calculation,
(2)
cloud-top
pressure
taken
operational
FRESCO-S
product.
comparison
between
POMINO
reprocessed
(RPRO)
products
April,
July
2021
well
January
2022
exhibits
high
spatial
agreement,
but
RPRO
are
lower
by
10
%
20
over
polluted
regions.
Sensitivity
tests
show
that
differences
mainly
caused
different
correction
methods
(implicit
versus
explicit),
prior
information
profile
shapes
background
corrections,
while
discrepancies
result
reflectances
their
nonlinear
interactions.
With
structural
uncertainty
due
within
±20
%,
height
differences.
Validation
against
ground-based
measurements
Multi-Axis
Differential
Optical
Absorption
Spectroscopy
(MAX-DOAS)
observations
Pandonia
Network
(PGN)
shows
retrievals
present
comparable
day-to-day
correlation
reduced
bias
(normalized
mean
bias,
NMB)
compared
(HCHO:
R=0.62,
NMB=-30.8%
R=0.68,
NMB=-35.0%;
NO2:
R=0.84,
NMB=-9.5%
R=0.85,
NMB=-19.4%).
An
improved
agreement
HCHO/NO2
ratio
(FNR,
ratio)
MAX-DOAS
PGN
based
also
found
(NMB:
−14.8
−21.1
%).
Our
provides
useful
source
information,
particularly
studies
combining
NO2.
Journal of Geophysical Research Atmospheres,
Journal Year:
2024,
Volume and Issue:
129(4)
Published: Feb. 14, 2024
Abstract
The
impacts
on
atmospheric
ozone
(O
3
)
due
to
wildfires
are
difficult
characterize
the
many
factors
that
affect
O
's
formation
rate
and
episodic
nature
of
fire
events.
This
study
uses
a
very
large
set
air
quality
data
(518,987
6‐hr
points)
collected
in
Western
Canada
from
2001
2019
determine
prevalence
severity
fire‐driven
increases
measured
values.
Wildfire
events
identified
using
automated
Trajectory‐Fire
Interception
Method
(TFIM),
looking
for
interceptions
between
HYSPLIT
back‐trajectories
wildfire
hotspots.
As
with
other
studies,
which
have
used
more
restricted
sets
measurements,
results
this
large‐scale,
data‐driven
approach
indicate
mixing
ratio
impact,
average
∼2
ppbv
across
all
time
periods.
To
understand
lead
largest
increases,
better
compare
studies
at
individual
events,
classified
their
distance
measurement
location,
measurement,
corresponding
PM
2.5
value.
Increases
during
daytime,
when
fires
occur
close
measurements
>
25
μg/m
.
When
an
upper‐limit
correction
bias
UV
photometric
detection
MnCl
2
scrubbers
is
applied,
analysis
still
yields
persistent
increase
except
highest
levels.
However,
accurate
potential
needed
fully
magnitude
impact
Wildfires
are
an
increasing
source
of
emissions
into
the
air,
with
health
effects
modulated
by
abundance
and
toxicity
individual
species.
In
this
work,
we
estimate
reactive
organic
compounds
(ROC)
in
western
U.S.
wildland
forest
fire
smoke
using
a
combination
observations
from
2019
Fire
Influence
on
Regional
to
Global
Environments
Air
Quality
(FIREX-AQ)
field
campaign
predictions
Community
Multiscale
(CMAQ)
model.
Standard
emission
inventory
methods
capture
40-45%
estimated
ROC
mass
emitted,
estimates
primary
aerosol
particularly
low
(5-8×).
Downwind,
gas-phase
species
abundances
molar
units
reflect
production
fragmentation
products
such
as
formaldehyde
methanol.
Mass-based
emphasize
larger
compounds,
which
tend
be
unidentified
at
level,
less
volatile,
typically
not
measured
gas
phase.
total
1250
±
60
g·C
per
kg·C
CO,
implying
much
carbon
is
emitted
CO.
Particulate
has
potential
dominate
cancer
noncancer
risk
long-term
exposure
inhaled
smoke,
better
constraining
these
will
require
information
particulate
fires.
Authorea (Authorea),
Journal Year:
2024,
Volume and Issue:
unknown
Published: June 10, 2024
Temperature
is
the
principal
driver
of
global
HCHO
and
its
primary
oxidation
precursor
biogenic
volatile
organic
compounds
(BVOCs).
We
revisit
such
a
temperature
(T-)
dependency
globally,
leveraging
TROPOMI
column
data.
find
substantial
variations
in
T-dependency
across
plant
functional
types
(PFTs),
with
highest
over
Broadleaf
Evergreen
Tropical
Trees
(doubling
every
6.0
K
±
2.1
K)
lowest
Arctic
C3
Grass
30.8
9.6
K).
The
GEOS-Chem
model
interprets
columns’
at
PFT
level
(r
=
0.87),
16%
discrepancy
on
average.
can
be
explained
by
BVOC
emissions
for
Warm
C4
attributed
to
insensitivity
columns
other
PFTs.
Our
findings
underscore
potentially
magnified
variation
MEGAN
therein,
particularly
regions
experiencing
greater
variations.
