Abstract.
A
comprehensive
understanding
of
the
effects
meteorology,
emissions,
and
chemistry
on
severe
haze
is
critical
in
mitigation
air
pollution.
However,
such
an
greatly
hindered
by
nonlinearity
atmospheric
systems.
In
this
study,
we
developed
quantitative
decoupling
analysis
(QDA)
method
to
quantify
chemical
reactions,
their
nonlinear
interactions
fine
particulate
matter
(PM2.5)
pollution
running
built-in
scenario
simulations
each
model
step.
Different
from
previous
methods,
QDA
achieves
a
fully
decomposed
hourly
changes
PM2.5
concentration
during
events
into
seven
parts,
including
pure
meteorological
contribution
(M),
emissions
(E),
(C),
among
these
processes
(i.e.,
ME,
MC,
EC,
MCE).
Via
embedding
Weather
Research
Forecasting–Nested
Air
Quality
Prediction
Modeling
System,
employed
combined
it
with
Integrated
Process
Rate
study
typical
heavy
episode
Beijing.
We
evaluate
performance
against
in
situ
quality
observations
describe
analytical
factors
case.
Results
showed
that
M
varied
most
significantly
at
different
stages
episode,
0.21
µg⋅m−3⋅h−1
accumulation
stage
−11.82
removal
stage,
indicating
dominated
fluctuation
amplitude
concentration.
acted
as
important
cleaner
for
non-polluting
periods
but
stopped
being
effective
instead
became
contributor
tended
grow
rapidly
under
superimposed
influence
processes,
which
would
probably
mark
beginning
event.
The
E
ranged
0.63
0.88
owing
diurnal
variation
emissions.
was
shown
increase
level
haze,
becoming
largest
(0.37
µg⋅m−3⋅h−1)
maintenance
period,
25
%
higher
than
pre-contamination
period.
And
C+CE
made
significant
stages,
reactions
are
more
polluted
period
other
periods.
Nonnegligible
exist
concentrations
(−1.83
2.44
–
something
has
generally
been
ignored
studies
development
heavy-pollution
control
strategies.
helpful
eliminating
interference
obtaining
purified
result
target
process
have
indicative
significances.
ratio
CE
C
positively
correlated
speed.
For
precursors
like
NH3,
smaller
value
indicated
NH3
deficient,
thus
reducing
had
efficient
controlling
effect
PM2.5.
This
highlights
can
be
used
realize
in-depth
adverse
conditions
judge
whether
excessive
or
not.
Not
only
provide
researchers
policymakers
valuable
information
key
behind
pollution,
also
help
modelers
identify
sources
uncertainties
numerical
models.
Atmospheric Pollution Research,
Journal Year:
2024,
Volume and Issue:
15(7), P. 102147 - 102147
Published: April 10, 2024
In
areas
where
the
regional
transport
of
air
pollutants
exerts
a
significant
impact,
ascertaining
whether
short-term
stagnation
affects
PM2.5
concentrations
is
crucial
for
accurate
quality
forecasting
and
effective
management
planning.
However,
this
research
area
remains
underexplored.
study,
we
analyzed
relationship
between
stagnant
atmospheric
conditions
daily
average
in
with
substantial
long-range
impact
(LRT).
Specifically,
focused
on
days
elevated
(daily
≥
35
μg/m3)
from
January
to
March
2019
South
Korea.
The
analysis
was
performed
using
Weather
Research
Forecasting
Community
Multiscale
Air
Quality
Modeling
System.
Stagnant
were
quantified
ventilation
index
(VI),
calculated
as
product
planetary
boundary
layer
height
10-m
wind
speed.
correlation
coefficient
VI
(r
=
–0.23)
lower
than
that
NO2
–0.60).
This
can
be
attributed
fact
LRT
2.9-fold
higher
local
emission
(LEI)
during
concentrations.
Notably,
–0.03)
considerably
LEI
–0.70).
Hence,
predicting
concentration
solely
based
proved
challenging
an
characterized
by
LRT.
For
future
research,
plays
role,
prediction
requires
distinguishing
effects
Environmental Research Letters,
Journal Year:
2024,
Volume and Issue:
19(5), P. 054006 - 054006
Published: March 25, 2024
Abstract
As
the
concentration
of
fine
particles
(PM
2.5
)
is
declining,
ozone
(O
3
has
been
increasing
in
China
recent
years.
To
collaboratively
control
PM
and
O
,
it
critical
to
understand
relationship
between
two
identify
major
controlling
factors.
We
use
a
convergent
cross-mapping
method
detect
causal
daily
maximum
8
h
average
(MDA8)
concentrations
Beijing,
Taizhou,
Shenzhen
Chengdu,
China,
four
seasons
2015–2021.
In
addition,
we
also
examined
effects
atmospheric
oxidation
capacity,
precursors
meteorological
elements
on
MDA8
cities.
are
strongly
positively
correlated
show
bidirectional
relationships
during
Beijing
Taizhou
summer
Shenzhen,
due
mainly
strong
photochemical
reactions
daytime.
During
winter,
relationships,
but
significantly
negatively
correlated,
driven
by
NO
2
relative
humidity.
Weak
bidirectional,
unidirectional
no
detected
other
these
cities,
top
three
factors
differ
from
those
.
Season-,
city-
pollutant-specific
measures
required.
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(13), P. 7623 - 7636
Published: July 5, 2024
Abstract.
High
contents
of
reactive
nitrogen
components
aggravate
air
pollution
and
could
also
impact
ecosystem
structures
functioning
across
the
terrestrial–aquatic–marine
continuum.
However,
long-term
historical
trends
future
predictions
at
global
scale
still
remain
highly
uncertain.
In
our
study,
field
observations,
satellite
products,
model
outputs,
many
other
covariates
were
integrated
into
multi-stage
machine-learning
to
capture
patterns
during
2000–2019.
order
decrease
estimate
uncertainties
in
scenarios,
constructed
component
dataset
for
period
was
utilised
as
constraint
calibrate
CMIP6
four
scenarios.
The
results
suggested
that
cross-validation
(CV)
R2
values
species
showed
satisfying
performance
(R2>0.55).
concentrations
estimated
China
experienced
persistent
increases
2000–2013,
while
they
suffered
drastic
decreases
from
2013,
except
NH3.
This
might
be
associated
with
clean-air
policies.
Europe
United
States,
these
compounds
have
remained
relatively
stable
since
2000.
SSP3-7.0
(traditional-energy
scenario)
SSP1-2.6
(carbon
neutrality
highest
lowest
concentrations,
respectively.
Although
some
heavy-pollution
scenarios
(SSP3-7.0)
2020–2100,
SSP2-4.5
(middle-emission
more
rapidly
decreasing
trends.
Our
emphasise
need
carbon
pathways
reduce
atmospheric
N
pollution.
Journal of Advances in Modeling Earth Systems,
Journal Year:
2024,
Volume and Issue:
16(11)
Published: Nov. 1, 2024
Abstract
A
comprehensive
understanding
of
meteorological,
emission
and
chemical
influences
on
severe
haze
is
essential
for
air
pollution
mitigation.
However,
the
nonlinearity
atmospheric
system
greatly
hinders
this
understanding.
In
study,
we
developed
quantitative
decoupling
analysis
(QDA)
method
by
applying
Factor
Separation
(FS)
into
model
processes
to
quantify
effects
emissions
(E),
meteorology
(M),
reactions
(C),
their
nonlinear
interactions
impact
fine
particulate
matter
(PM
2.5
)
pollution.
Taking
a
heavy‐haze
episode
in
Beijing
as
an
example,
show
that
different
from
integrated
process
rate
(IPR)
scenario
approach
(SAA)
previous
studies,
QDA
explicitly
demonstrate
decomposing
variation
PM
concentration
individual
contributions
E
,
M
C
terms
well
among
these
processes.
Results
showed
dominated
hourly
fluctuation
concentration.
The
increase
with
increasing
level
haze,
reaching
maximum
(0.37
μg
m
−3
h
−1
at
maintenance
stage.
Moreover,
our
reveals
there
are
non‐negligible
non‐linear
emission,
during
stage,
mean
accounting
50%
concentrations,
which
often
ignored
current
control
strategies.
This
study
highlights
can
be
used
gain
insight
formation
heavy
pollution,
identify
uncertainty
numerical
models.
Abstract.
High
contents
of
reactive
nitrogen
components
aggravate
air
pollution
and
could
also
impact
ecosystem
structure
function
across
the
terrestrial-aquatic-marine
continuum.
However,
long-term
historical
trends
future
prediction
at
global
scale
still
remains
high
uncertainties.
In
our
study,
field
observations,
satellite
products,
model
output,
many
other
covariates
were
integrated
into
machine-learning
to
capture
patterns
during
2000–2019.
order
decrease
estimate
uncertainties
in
scenarios,
constructed
component
dataset
period
was
then
utilized
as
constraint
calibrate
CMIP6
four
scenarios.
The
results
suggested
cross-validation
(CV)
R2
values
species
showed
satisfied
performance
(R2
>
0.55).
concentrations
estimated
China
experienced
persistent
increases
2000–2013,
while
they
suffered
from
drastic
decreases
since
2013
except
NH3.
It
might
be
associated
with
clean
policy.
these
compounds
Europe
United
States
remained
relatively
stable
2000.
SSP3-7.0
(traditional
energy
scenario)
SSP1-2.6
(carbon
neutrality
highest
lowest
concentrations,
respectively.
Although
some
heavy-pollution
scenarios
(SSP3-7.0)
2020–2100,
SSP2-4.5
(middle
emission
kept
more
rapid
decreasing
trends.
Our
emphasize
need
for
carbon-neutrality
pathway
reduce
atmospheric
N
pollution.