Abstract.
This
study
investigated
the
potential
effects
of
inorganics
changes
on
aerosol
water
uptake
and
thus
secondary
organic
(SOA)
formation
in
wintertime
haze,
based
size-resolved
measurements
non-refractory
fine
particulate
matter
(NR-PM2.5)
Xi’an,
Northwest
China.
The
composition
inorganic
showed
significant
winter
2018–2019
compared
to
2013–2014,
shifting
from
a
sulfate-rich
nitrate-rich
profile.
In
particular,
fraction
sulfate
chloride
decreased
but
nitrate
increased
entire
size
range,
while
ammonium
mainly
at
larger
particle
sizes.
These
resulted
size-dependent
evolution
uptake.
Increased
was
observed
most
cases
associated
with
enhanced
contributions
both
ammonium,
highest
increase
ratio
reaching
5–35
%
sizes
higher
relative-humidity
(RH).
non-negligible
influence
also
emphasized.
random
forest
analysis
coupled
Shapley
additive
explanation
algorithm
(SHAP)
further
relative
importance
impacting
SOA
formation.
Aerosol
contributed
2018–2019,
SHAP
value
as
increased,
especially
implies
majority
high
RH
might
facilitate
efficient
aqueous-phase
highlights
key
role
medium
link
organics
their
multiphase
processes.
As
challenges
improve
China's
air
quality
remain
plays
an
increasing
haze
pollution,
these
results
provide
insight
into
characteristics
offer
guidance
for
future
control.
Remote Sensing,
Год журнала:
2023,
Номер
15(2), С. 358 - 358
Опубликована: Янв. 6, 2023
Atmospheric
fine
particles
(PM2.5)
have
been
found
to
be
harmful
the
environment
and
human
health.
Recently,
remote
sensing
technology
machine
learning
models
used
monitor
PM2.5
concentrations.
Partial
dependence
plots
(PDP)
were
explore
meteorology
mechanisms
between
predictor
variables
concentration
in
“black
box”
models.
However,
there
are
two
key
shortcomings
original
PDP.
(1)
it
calculates
marginal
effect
of
feature(s)
on
predicted
outcome
a
model,
therefore
some
local
effects
might
hidden.
(2)
requires
that
for
which
partial
is
computed
not
correlated
with
other
features,
otherwise
estimated
feature
has
great
bias.
In
this
study,
PDP’s
analyzed.
Results
show
contradictory
correlation
temperature
can
given
by
Furthermore,
spatiotemporal
heterogeneity
PM2.5-AOD
relationship
cannot
displayed
well
The
drawbacks
PDP
make
unsuitable
exploring
large-area
effects.
To
resolve
above
issue,
multi-way
recommended,
characterize
how
concentrations
changed
temporal
spatial
variations
major
meteorological
factors
China.
Environment International,
Год журнала:
2024,
Номер
187, С. 108724 - 108724
Опубликована: Май 1, 2024
The
mass
concentration
of
atmospheric
particulate
matter
(PM)
has
been
continuously
decreasing
in
the
Beijing-Tianjin-Hebei
region.
However,
health
endpoints
do
not
exhibit
a
linear
correlation
with
PM
concentrations.
Thus,
it
is
urgent
to
clarify
prior
toxicological
components
further
improve
air
quality.
In
this
study,
we
analyzed
long-term
oxidative
potential
(OP)
water-soluble
PM2.5,
which
generally
considered
more
effective
assessing
hazardous
exposure
Beijing
from
2018
2022
based
on
dithiothreitol
assay
and
identified
crucial
drivers
OP
PM2.5
online
monitoring
pollutants,
receptor
model,
random
forest
(RF)
model.
Our
results
indicate
that
dust,
traffic,
biomass
combustion
are
main
sources
Beijing.
complex
interactions
dust
particles,
black
carbon,
gaseous
pollutants
(nitrogen
dioxide
sulfur
dioxide)
factors
driving
evolution,
particular,
leading
abnormal
rise
2022.
data
shows
higher
observed
winter
spring
compared
summer
autumn.
diurnal
variation
characterized
by
declining
trend
0:00
14:00
an
increasing
23:00.
spatial
was
as
lower
than
Shijiazhuang,
while
Zhenjiang
Haikou,
primarily
influenced
distribution
carbon.
significance
identifying
key
influencing
provide
new
insights
for
advancing
quality
improvement
efforts
focus
safeguarding
human
Atmospheric chemistry and physics,
Год журнала:
2023,
Номер
23(6), С. 3595 - 3607
Опубликована: Март 23, 2023
Abstract.
The
Fenwei
Plain,
home
to
50
million
people
in
central
China,
is
one
of
the
most
polluted
regions
China.
In
2018,
Plain
was
designated
as
three
key
for
“Blue
Sky
Protection
Campaign”,
along
with
Beijing–Tianjin–Hebei
(BTH)
and
Yangtze
River
Delta
(YRD)
regions.
However,
compared
BTH
YRD,
our
understanding
current
status
air
pollution
limited
partly
due
a
lack
detailed
analysis
transformation
from
precursor
gases
secondary
products
including
organic
aerosol
(SOA)
ozone.
Through
7
years
(2015–2021)
surface
monitoring
pollutants
Xi'an,
largest
city
we
show
that
roughly
two-thirds
days
exceeded
either
PM2.5
or
O3
level-1
quality
standard,
highlighting
severity
pollution.
Moreover,
an
increase
winter
haze
also
revealed,
constantly
elevated
reactive
oxygenated
volatile
compounds
(OVOCs),
particular
formaldehyde,
ozone
formation
potential
over
µg
m−3,
combination
reduced
NO2.
abrupt
decrease
NO2,
observed
during
lockdown
2020,
provided
real-world
evidence
control
measures,
targeting
only
NOx
(70
%
on
average),
were
insufficient
reduce
because
OVOCs
remained
high
compound
(VOC)-limited
regime.
Model
simulation
results
showed
NO2
reduction
20
%–70
%,
self-reaction
rate
between
peroxy
radicals,
pathway
SOA
formation,
intensified
by
up
75
while
further
VOCs
>
%.
Therefore,
synergic
can
be
achieved
through
more
aggressive
their
gases.
This
study
elucidates
revealing
general
trend
increasing
pollution,
i.e.,
haze.
Controlling
gas
emissions
anticipated
curb
both
which
will
benefit
not
just
but
other
npj Climate and Atmospheric Science,
Год журнала:
2023,
Номер
6(1)
Опубликована: Дек. 20, 2023
Abstract
Traditional
statistical
methods
(TSM)
and
machine
learning
(ML)
have
been
widely
used
to
separate
the
effects
of
emissions
meteorology
on
air
pollutant
concentrations,
while
their
performance
compared
chemistry
transport
model
has
less
fully
investigated.
Using
Community
Multiscale
Air
Quality
Model
(CMAQ)
as
a
reference,
series
experiments
was
conducted
comprehensively
investigate
TSM
(e.g.,
multiple
linear
regression
Kolmogorov–Zurbenko
filter)
ML
random
forest
extreme
gradient
boosting)
approaches
in
quantifying
trends
fine
particulate
matter
(PM
2.5
)
during
2013−2017.
evaluation
metrics
suggested
that
can
explain
variations
PM
with
highest
from
ML.
The
showed
insignificant
differences
(
p
>
0.05)
for
both
emission-related
$${{\rm{PM}}}_{2.5}^{{\rm{EMI}}}$$
PM2.5EMI
meteorology-related
components
between
TSM,
ML,
CMAQ
modeling
results.
estimated
least
difference
CMAQ.
Considering
medium
computing
resources
low
biases,
method
is
recommended
weather
normalization
.
Sensitivity
analysis
further
optimized
hyperparameters
exclusion
temporal
variables
produce
reasonable
results
Aerosol and Air Quality Research,
Год журнала:
2025,
Номер
25(1-4)
Опубликована: Март 27, 2025
Abstract
Introduction
PM
2.5
pollution
is
a
significant
environmental
and
health
concern
in
Thailand,
with
levels
intensifying
during
the
dry
season.
However,
lack
of
long-term
PM2.5
data
limits
understanding
historical
trends
meteorological
influences.
Objective
This
study
aims
to
reconstruct
from
1981
2022
analyze
influence
various
contributing
factors
across
six
key
provinces
Thailand:
Chiang
Mai
(CM),
Lampang
(LP),
Khon
Kaen
(KK),
Bangkok
(BK),
Chonburi
(CB),
Songkhla
(SK).
Methods
A
Light
Gradient
Boosting
Machine
(LightGBM)
model
was
developed
using
aerosol-related
variables
Thai
Meteorological
Department
MERRA-2.
The
trained
on
spanning
2012–2022,
depending
availability
for
each
province.
Model
performance
evaluated
diurnal,
monthly,
annual
scales
then
used
reconstruction
data.
SHAP
analysis
determine
important
predictor
affecting
prediction.
Results
LightGBM
accurately
predicted
all
provinces,
showing
better
daily
prediction
than
hourly
accuracy
higher
clean
hours
haze
hours.
Good
agreement
between
observed
found
different
time
(diurnal,
annually).
CM
shows
non-significant
trend,
limiting
insights
into
effects,
while
LP
exhibits
decreases
PM2.5_emis,
indicating
positive
weather
impacts
air
quality.
In
contrast,
regions
like
KK,
BK,
CB
display
worsening
influences,
or
increasing
despite
declines
_emis.
SK,
removing
effects
reveals
decreasing
underscoring
critical
role
meteorology.
identified
visibility,
gridded
,
specific
humidity
at
2
m
as
common
over
along
additional
that
were
not
consistent
provinces.
Conclusion
effectively
reconstructs
provides
insight
influences
Based
findings
study,
some
policy
implications
have
also
been
provided.
Graphical
abstract