In situ vertical observations of the layered structure of air pollution in a continental high-latitude urban boundary layer during winter
Atmospheric chemistry and physics,
Journal Year:
2025,
Volume and Issue:
25(6), P. 3687 - 3715
Published: March 27, 2025
Abstract.
Vertical
in
situ
measurements
of
aerosols
and
trace
gases
were
conducted
Fairbanks,
Alaska,
during
winter
2022
as
part
the
Alaskan
Layered
Pollution
Chemical
Analysis
campaign
(ALPACA).
Using
a
tethered
balloon,
study
explores
dispersion
pollutants
continental
high-latitude
stable
boundary
layer
(SBL).
24
flights
revealed
stratified
SBL
structure
with
different
pollution
layers
lowest
tens
meters
atmosphere,
offering
unprecedented
detail.
Surface
emissions
generally
accumulated
surface
mixing
(ML)
extending
to
an
average
51
m,
well-mixed
sublayer
(MsL)
reaching
22
m.
The
height
concentrations
within
ML
strongly
influenced
by
local
wind
driven
nearby
topography
under
anticyclonic
conditions.
During
strong
radiative
cooling,
drainage
flow
increased
turbulence
near
surface,
altering
temperature
profile
deepening
ML.
Above
ML,
decreased
but
showed
clear
signs
freshly
released
anthropogenic
emissions.
Higher
above
elevated
inversions,
levels
similar
previously
reported
Arctic
haze
concentrations,
even
though
Fairbanks'
outflow
below
inversions
up
6
times
higher,
likely
due
power
plant
In
indicated
that
gas
particle
tracer
ratios
plumes
differed
significantly
from
those
surface.
Overall,
correlated
stratification
emission
heights,
emphasizing
need
for
improved
representation
sources
air
quality
models
enhance
forecasts.
Language: Английский
Residential Wood Burning and Vehicle Emissions as Major Sources of Environmentally Persistent Free Radicals in Fairbanks, Alaska
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(32), P. 14293 - 14305
Published: Aug. 2, 2024
Environmentally
persistent
free
radicals
(EPFRs)
play
an
important
role
in
aerosol
effects
on
air
quality
and
public
health,
but
their
atmospheric
abundance
sources
are
poorly
understood.
We
measured
EPFRs
contained
PM2.5
collected
Fairbanks,
Alaska,
winter
2022.
find
that
EPFR
concentrations
were
enhanced
during
surface-based
inversion
correlate
strongly
with
incomplete
combustion
markers,
including
carbon
monoxide
elemental
(R2
>
0.75).
exhibit
moderately
good
correlations
PAHs,
biomass
burning
organic
aerosols,
potassium
0.4).
also
observe
strong
of
hydrocarbon-like
Fe
Ti
0.6),
single-particle
mass
spectrometry
measurements
reveal
internal
mixing
iron.
These
results
suggest
residential
wood
vehicle
tailpipes
major
nontailpipe
emissions,
such
as
brake
wear
road
dust,
may
contribute
to
the
stabilization
EPFRs.
Exposure
observed
(18
±
12
pmol
m–3)
would
be
equivalent
smoking
∼0.4–1
cigarette
daily.
Very
0.8)
hydroxyl
radical
formation
surrogate
lung
fluid
indicate
exposure
induce
oxidative
stress
human
respiratory
tract.
Language: Английский
Spatial and Seasonal Variability of Remote and Urban Speciated Fine Particulate Matter in the United States
Journal of Geophysical Research Atmospheres,
Journal Year:
2024,
Volume and Issue:
129(23)
Published: Dec. 1, 2024
Abstract
The
spatial
and
seasonal
variability
in
the
composition
of
major
PM
2.5
(particles
with
aerodynamic
diameters
less
than
μm)
aerosol
species
United
States
were
characterized
using
data
from
ground‐based
monitoring
networks.
IMPROVE
(Interagency
Monitoring
Protected
Visual
Environments)
network
Chemical
Speciation
Network
(CSN)
operate
mostly
rural/remote
or
urban/suburban
sites,
respectively.
networks
have
similar
sampling
schedules
analysis
methods.
Regional,
monthly,
annual
mean
concentrations
2019
to
2022
calculated
for
ammonium
sulfate
(AS),
nitrate
(AN),
particulate
organic
matter
(POM),
elemental
carbon
(EC),
fine
dust
(FD),
sea
salt
(SS),
as
well
their
relative
contributions
reconstructed
mass
(RCFM).
Organic
aerosols
largest
contributor
RCFM
across
(>40%
annually,
up
80%
monthly),
significant
impacts
biomass
smoke
on
POM
EC
concentrations,
contributions,
seasonality.
AS
urban
rural
regions
contributed
<20%
annually
RCFM,
considerably
two
decades
ago.
In
general,
greater
AN,
POM,
EC,
suggesting
additional
sources.
Some
species,
such
FD,
exhibited
strong
due
episodic
source
formation
conditions.
Evaluating
monthly
is
necessary
understanding
emission
sources,
regional
transport,
atmospheric
processes
governing
atmosphere.
Language: Английский