ACS Earth and Space Chemistry,
Год журнала:
2022,
Номер
6(4), С. 1067 - 1079
Опубликована: Март 31, 2022
Phenolic
compounds
emitted
from
wildfires
contribute
to
secondary
organic
aerosol
(SOA)
and
brown
carbon
(BrC)
upon
oxidation
initiated
by
hydroxyl
(OH)
nitrate
radicals
(NO3).
We
conducted
a
set
of
laboratory
chamber
experiments
study
catechol
OH
NO3
with
focus
on
the
associated
SOA
formation
evolution
under
conditions
relevant
fresh
wildfire
plumes.
Oxidation
products
in
both
gas
particle
phases
as
well
volatility
were
measured
using
an
iodide-adduct
high-resolution
time-of-flight
chemical
ionization
mass
spectrometer
coupled
filter
inlet
for
gases
aerosols
(FIGAERO-CIMS).
Nitrocatechol
(C6H5NO4)
was
dominant
particle-phase
compound
OH-initiated
NO3-initiated
strongly
light
absorption
at
405
nm,
consistent
BrC.
Maximum
yields,
ranging
0.1
1.6
OH-
NO3-driven
experiments,
respectively,
varied
net
nitrocatechol.
Gas–particle
partitioning
measurements
implied
effective
saturation
vapor
concentration,
c*,
nitrocatechol
is
12
μg
m–3
experiment
2.4
far
lower
than
group
contribution
method
estimates,
which
ranged
1.8
×
102
8.5
108
m–3.
In
extended
photochemical
aging
wall-loss-corrected
lifetimes
BrC
17.4
±
0.8
12.4
h,
while
particulate
had
21
8
6.9
0.6
h
conditions,
respectively.
Implications
phenolic-derived
plumes
are
discussed.
Wildfires
are
a
substantial
but
poorly
quantified
source
of
tropospheric
ozone
(O3).
Here,
to
investigate
the
highly
variable
O3
chemistry
in
wildfire
plumes,
we
exploit
situ
chemical
characterization
western
wildfires
during
FIREX-AQ
flight
campaign
and
show
that
production
can
be
predicted
as
function
experimentally
constrained
OH
exposure,
volatile
organic
compound
(VOC)
reactivity,
fate
peroxy
radicals.
The
exhibits
rapid
transition
regimes.
Within
few
daylight
hours,
formation
substantially
slows
is
largely
limited
by
abundance
nitrogen
oxides
(NOx).
This
finding
supports
previous
observations
enhanced
when
VOC-rich
smoke
mixes
into
NOx-rich
urban
thereby
deteriorating
air
quality.
Last,
relate
underlying
fire
characteristics,
enabling
more
accurate
representation
atmospheric
models
used
study
quality
predict
climate.
Proceedings of the National Academy of Sciences,
Год журнала:
2021,
Номер
118(52)
Опубликована: Дек. 20, 2021
Significance
Understanding
the
sources
of
tropospheric
ozone
is
important
for
effective
air
quality
management
and
accurate
radiative
forcing
attribution.
Biomass
burning
emits
large
quantities
precursors
to
lower
atmosphere.
This
source
can
drive
regional-scale
production,
but
its
impact
on
global
poorly
constrained.
Here,
we
present
unique
in
situ
aircraft
observations
continental
pollution
tracers.
Ozone
enhancements
attributable
biomass
equal
or
exceed
those
from
urban
emissions,
a
result
that
not
predicted
by
current
chemical
transport
models.
These
findings
represent
potentially
major
shift
understanding
atmosphere
indicate
need
model
developments
improve
representation
ozone.
Journal of Geophysical Research Atmospheres,
Год журнала:
2022,
Номер
128(2)
Опубликована: Дек. 30, 2022
Abstract
The
NOAA/NASA
Fire
Influence
on
Regional
to
Global
Environments
and
Air
Quality
(FIREX‐AQ)
experiment
was
a
multi‐agency,
inter‐disciplinary
research
effort
to:
(a)
obtain
detailed
measurements
of
trace
gas
aerosol
emissions
from
wildfires
prescribed
fires
using
aircraft,
satellites
ground‐based
instruments,
(b)
make
extensive
suborbital
remote
sensing
fire
dynamics,
(c)
assess
local,
regional,
global
modeling
fires,
(d)
strengthen
connections
observables
the
ground
such
as
fuels
fuel
consumption
satellite
products
burned
area
radiative
power.
From
Boise,
ID
western
were
studied
with
NASA
DC‐8
two
NOAA
Twin
Otter
aircraft.
high‐altitude
ER‐2
deployed
Palmdale,
CA
observe
some
these
in
conjunction
overpasses
other
Further
conducted
three
mobile
laboratories
sites,
17
different
forecast
analyses
for
fire,
air
quality
climate
implications.
Salina,
KS
investigated
87
smaller
Southeast
in‐situ
data
collection.
Sampling
by
all
platforms
designed
measure
gases
aerosols
multiple
transects
capture
chemical
transformation
perform
observations
smoke
plumes
under
day
night
conditions.
linked
consumed
power
orbital
collected
during
overflights
sampling
fuels.
Atmospheric chemistry and physics,
Год журнала:
2024,
Номер
24(2), С. 929 - 956
Опубликована: Янв. 23, 2024
Abstract.
Extensive
airborne
measurements
of
non-methane
organic
gases
(NMOGs),
methane,
nitrogen
oxides,
reduced
species,
and
aerosol
emissions
from
US
wild
prescribed
fires
were
conducted
during
the
2019
NOAA/NASA
Fire
Influence
on
Regional
to
Global
Environments
Air
Quality
campaign
(FIREX-AQ).
Here,
we
report
atmospheric
enhancement
ratios
(ERs)
inferred
emission
factors
(EFs)
for
compounds
measured
board
NASA
DC-8
research
aircraft
nine
wildfires
one
fire,
which
encompass
a
range
vegetation
types.
We
use
photochemical
proxies
identify
young
smoke
reduce
effects
chemical
degradation
our
calculations.
ERs
EFs
calculated
FIREX-AQ
observations
agree
within
factor
2,
with
values
reported
previous
laboratory
field
studies
more
than
80
%
carbon-
nitrogen-containing
species.
Wildfire
are
parameterized
based
correlations
sum
NMOGs
reactive
oxides
(NOy)
modified
combustion
efficiency
(MCE)
as
well
other
signatures
indicative
flaming/smoldering
combustion,
including
carbon
monoxide
(CO),
dioxide
(NO2),
black
aerosol.
The
primary
NMOG
correlates
MCE
an
R2
0.68
slope
−296
±
51
g
kg−1,
consistent
studies.
mixing
CO
0.98
137
4
ppbv
per
parts
million
by
volume
(ppmv)
CO,
demonstrating
that
can
be
estimated
CO.
Individual
species
correlate
better
NO2,
NOy,
More
half
NOy
in
fresh
plumes
is
NO2
0.95
ratio
0.55
0.05
ppbv−1,
highlighting
fast
photochemistry
had
already
occurred
sampled
fire
plumes.
follows
trends
observed
experiments
increases
exponentially
MCE,
due
increased
key
at
higher
flaming
combustion.
These
parameterizations
will
provide
accurate
boundary
conditions
modeling
satellite
plume
chemistry
evolution
predict
downwind
formation
secondary
pollutants,
ozone
Atmospheric chemistry and physics,
Год журнала:
2021,
Номер
21(21), С. 16293 - 16317
Опубликована: Ноя. 8, 2021
Abstract.
Wildfires
are
increasing
in
size
across
the
western
US,
leading
to
increases
human
smoke
exposure
and
associated
negative
health
impacts.
The
impact
of
biomass
burning
(BB)
smoke,
including
wildfires,
on
regional
air
quality
depends
emissions,
transport,
chemistry,
oxidation
emitted
BB
volatile
organic
compounds
(BBVOCs)
by
hydroxyl
radical
(OH),
nitrate
(NO3),
ozone
(O3).
During
daytime,
when
light
penetrates
plumes,
BBVOCs
oxidized
mainly
O3
OH.
In
contrast,
at
night
or
optically
dense
NO3.
This
work
focuses
transition
between
daytime
nighttime
oxidation,
which
has
significant
implications
for
formation
secondary
pollutants
loss
nitrogen
oxides
(NOx=NO+NO2)
been
understudied.
We
present
wildfire
plume
observations
made
during
FIREX-AQ
(Fire
Influence
Regional
Global
Environments
Air
Quality),
a
field
campaign
involving
multiple
aircraft,
ground,
satellite,
mobile
platforms
that
took
place
United
States
summer
2019
study
both
agricultural
emissions
atmospheric
chemistry.
use
from
two
research
NASA
DC-8
NOAA
Twin
Otter,
with
detailed
chemical
box
model,
updated
phenolic
mechanisms,
analyze
sampled
midday,
sunset,
nighttime.
Aircraft
suggest
range
NO3
production
rates
(0.1–1.5
ppbv
h−1)
plumes
transported
midday
after
dark.
Modeled
initial
instantaneous
reactivity
toward
NO3,
OH,
is
80.1
%,
87.7
99.6
respectively.
Initial
10–104
times
greater
than
typical
values
forested
urban
environments,
reactions
account
>97
%
sunlit
(jNO2
up
4×10-3s-1),
while
conventional
photochemical
through
reaction
NO
photolysis
minor
pathways.
Alkenes
furans
mostly
OH
(11
%–43
54
%–88
alkenes;
18
%–55
39
%–76
furans,
respectively),
but
split
O3,
(26
%–52
22
16
%–33
respectively).
Nitrate
accounts
26
sunset
an
thick
plume.
Nitrocatechol
yields
varied
33
45
chemistry
late
day
responsible
72
%–92
(84
plume)
nitrocatechol
controls
nitrophenolic
overall.
As
result,
overnight
pathways
56
%±2
NOx
sunrise
following
day.
all
one
we
modeled,
there
was
remaining
(13
%–57
%)
(8
%–72
sunrise.
Geophysical Research Letters,
Год журнала:
2022,
Номер
49(9)
Опубликована: Апрель 12, 2022
Abstract
Biomass
burning
is
a
major
source
of
light‐absorbing
organic
aerosol
(brown
carbon),
but
its
composition,
chemical
evolution,
and
lifetime
are
not
well
known.
We
measured
water‐soluble
brown
carbon
absorption
from
310
to
500
nm
on
the
National
Oceanic
Atmospheric
Administration
Twin
Otter
aircraft
during
flights
downwind
western
United
States
wildfires
in
summer
2019.
The
sampling
strategy
was
near‐Lagrangian
plume
ages
spanned
0–5
hr.
Trends
mass
coefficient
with
age
varied
between
flights,
did
show
an
exponential
decay
over
these
short
time
scales.
spectra
were
smoothly
varying,
without
identifiable
contributions
individual
chromophores
structured
absorption.
Using
tracer
ions
reference
spectra,
calculated
contribution
4‐nitrocatechol
total
<22
±
9%
<11
5%,
although
spectral
fitting
showed
that
it
may
be
as
low
<1.1%
<0.6%
at
365
405
nm,
respectively.
Environmental Science & Technology,
Год журнала:
2023,
Номер
57(3), С. 1257 - 1267
Опубликована: Янв. 6, 2023
Increasing
trends
in
biomass
burning
emissions
significantly
impact
air
quality
North
America.
Enhanced
mixing
ratios
of
ozone
(O3)
urban
areas
during
smoke-impacted
periods
occur
through
transport
O3
produced
within
the
smoke
or
pyrogenic
volatile
organic
compounds
(PVOCs)
with
nitrogen
oxides
(NOx
=
NO
+
NO2)
to
enhance
local
production.
Here,
we
analyze
a
set
detailed
chemical
measurements,
including
carbon
monoxide
(CO),
NOx,
and
speciated
(VOCs),
evaluate
effects
transported
from
relatively
long-range
fires
on
measured
at
site
Boulder,
Colorado,
summer
2020.
Relative
smoke-free
period,
CO,
background
O3,
OH
reactivity,
total
VOCs
increased
both
periods,
but
NOx
remained
approximately
constant.
These
observations
are
consistent
PVOCs
(comprised
primarily
oxygenates)
not
influence
upwind
area.
Box-model
calculations
show
that
production
all
three
was
NOx-sensitive
regime.
Consequently,
this
locally
similar
insensitive
increase
PVOCs.
However,
calculated
sensitivities
substantially
transition
NOx-saturated
(VOC-sensitive)
regimes.
results
suggest
(1)
is
main
driver
for
increases
(2)
may
cause
an
additional
areas.
Additional
VOC
measurements
impacted
necessary
broadly
quantify
wildfire
develop
effective
mitigation
strategies.
Environmental Science & Technology,
Год журнала:
2023,
Номер
57(39), С. 14648 - 14660
Опубликована: Сен. 13, 2023
The
frequency
of
wildfires
in
the
western
United
States
has
escalated
recent
decades.
Here
we
examine
impacts
on
ground-level
ozone
(O3)
precursors
and
O3-NOx-VOC
chemistry
from
source
to
downwind
urban
areas.
We
use
satellite
retrievals
nitrogen
dioxide
(NO2)
formaldehyde
(HCHO,
an
indicator
VOC)
Tropospheric
Monitoring
Instrument
(TROPOMI)
track
evolution
O3
over
California
2018
2020.
improved
these
by
updating
a
priori
profiles
explicitly
accounting
for
effects
smoke
aerosols.
TROPOMI
observations
reveal
that
extensive
intense
fire
2020
led
overall
increase
statewide
annual
average
HCHO
NO2
columns
16%
9%.
level
offsets
anthropogenic
NOx
emission
reduction
COVID-19
lockdown.
enhancement
within
plumes
is
concentrated
near
regions
actively
burning,
whereas
far-reaching,
extending
areas
due
secondary
production
longer-lived
VOCs
such
as
ethene.
Consequently,
larger
occurs
NOx-limited
regions,
while
greater
VOC-limited
areas,
both
contributing
more
efficient
production.
Atmospheric chemistry and physics,
Год журнала:
2025,
Номер
25(2), С. 1121 - 1143
Опубликована: Янв. 28, 2025
Abstract.
Volatile
chemical
products
(VCPs)
and
other
non-traditional
anthropogenic
sources,
such
as
cooking,
contribute
substantially
to
the
volatile
organic
compound
(VOC)
budget
in
urban
areas,
but
their
impact
on
ozone
formation
is
less
certain.
This
study
employs
Lagrangian
box
modeling
sensitivity
analyses
evaluate
response
sector-specific
VOC
nitrogen
oxide
(NOx)
emissions
two
Los
Angeles
(LA)
Basin
cities
during
summer
of
2021.
The
model
simulated
photochemical
processing
transport
temporally
spatially
gridded
from
FIVE-VCP-NEI17NRT
inventory
accurately
simulates
variability
magnitude
O3,
NOx,
speciated
VOCs
Pasadena,
CA.
show
that
(AVOC)
enhance
mean
daily
maximum
8
h
average
Pasadena
by
13
ppb,
whereas
biogenic
(BVOCs)
9.4
ppb.
Of
influenced
AVOCs,
VCPs
represent
largest
fraction
at
45
%,
while
cooking
fossil
fuel
are
comparable
26
%
29
respectively.
NOx
along
trajectory
paths
indicate
regime
varies
temporally.
modeled
primarily
NOx-saturated
across
dense
core
peak
production
Pasadena.
Lowering
25
moves
NOx-limited
chemistry
afternoon
hours
shrinks
spatial
extent
saturation
towards
downtown
LA.
Further
using
represented
a
separate
state
requires
steeper
reductions
transition
sensitivity,
further
suggesting
representing
reactivity
inventories
critical
determining
effectiveness
future
reduction
policies.