ACS ES&T Air,
Journal Year:
2024,
Volume and Issue:
1(10), P. 1252 - 1261
Published: Aug. 27, 2024
Nitrous
acid
(HONO)
is
a
key
precursor
of
the
hydroxyl
radical
(•OH),
playing
an
important
role
in
atmospheric
oxidation
capacity.
However,
unknown
sources
HONO
(Punknown)
are
frequently
reported
and
potential
controversial.
Here,
we
explored
Punknown
during
COVID-19
different
seasons
epidemic
control
phases
Shanghai
by
eXtreme
Gradient
Boosting
(XGBoost)
Shapley
Additive
Explanations
(SHAP)
for
first
time.
They
demonstrated
that
decrease
anthropogenic
activity
would
inhibit
secondary
formation
HONO,
as
policies
turned
strict.
The
explainable
machine
learning
revealed
nitrogen
dioxide
(NO2)
had
significant
impacts
on
spring
2020
(P1),
where
could
be
fully
explained
including
light-induced
heterogeneous
conversion
NO2
ground,
building,
aerosol
surfaces.
With
untightening
2021
(P3),
budget
came
to
balance
after
further
addition
photolysis
particulate
nitrate
(NO3–)
soil
emission.
As
P2
(summer),
decreased
54%
with
all
new
added.
These
results
provide
insights
into
chemistry
response
reduced
emissions,
improving
predictions
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(6), P. 2912 - 2921
Published: Jan. 22, 2024
Currently,
atmospheric
sulfate
aerosols
cannot
be
predicted
reliably
by
numerical
models
because
the
pathways
and
kinetics
of
formation
are
unclear.
Here,
we
systematically
investigated
synergetic
catalyzing
role
transition-metal
ions
(TMIs,
Fe3+/Mn2+)
in
oxidation
SO2
O2
on
using
chamber
experiments.
Our
results
showed
that
effect
TMIs
is
critically
dependent
aerosol
pH
due
to
solubility
Fe(III)
species
sensitive
aqueous
phase
acidity,
which
effective
only
under
<
3
conditions.
The
rate
2
orders
magnitude
larger
than
bulk
solution
increases
significantly
smaller
aerosols,
suggesting
such
a
synergetic-catalyzed
occurs
surface.
kinetic
reaction
can
described
as
R
=
k*[H+]−2.95[Mn(II)][Fe(III)][S(IV)]
(pH
≤
3.0).
We
found
TMI-synergetic-catalyzed
dominant
pathway
Beijing
when
haze
particles
very
acidic,
while
heterogeneous
NO2
most
important
weakly
acidic.
work
for
first
time
clarified
periods,
parameterized
into
future
studies
formation.
npj Climate and Atmospheric Science,
Journal Year:
2024,
Volume and Issue:
7(1)
Published: July 4, 2024
Abstract
Recently,
nitrate
(NO
3
–
)
levels
in
winter
pollution
eastern
China
have
been
increasing
yearly
and
become
the
main
component
of
PM
2.5
.
The
factors
contributing
to
this
rise
surface
NO
concentrations
remain
unclear,
complicating
development
targeted
control
measures.
This
study
utilizes
observational
data
from
Shanghai
during
2019,
alongside
box
model
simulations,
recreate
−
event
identify
key
growth
process.
analysis
demonstrated
that
a
ozone
significantly
promotes
production
by
facilitating
x
conversion
via
gas-phase
heterogeneous
reactions.
These
findings
could
explain
correlation
between
synchronous
increase
recent
years.
Furthermore,
simulation
strategies
for
volatile
organic
compounds
(VOCs)
identified
an
approach
centered
on
reduction
as
notably
effective
mitigating
Yangtze
River
Delta.
Atmosphere,
Journal Year:
2024,
Volume and Issue:
15(2), P. 172 - 172
Published: Jan. 29, 2024
This
study
presents
an
approach
using
multiple
linear
regression
to
quantify
the
impact
of
meteorological
parameters
and
chemical
species
on
aerosol
pH
variance
in
urban
setting
Pearl
River
Delta,
China.
Additionally,
it
assesses
contributions
interactions
among
these
factors
pH.
The
analysis
successfully
explains
over
96%
variance,
attributing
85.8%
original
variables
6.7%
bivariate
interactions,
with
further
2.3%
1.0%
from
trivariate
quadrivariate
respectively.
Our
results
highlight
that
factors,
particularly
temperature
humidity,
are
more
influential
than
components
affecting
variance.
Temperature
alone
accounts
for
37.3%
while
humidity
contributes
approximately
20%.
On
front,
sulfate
ammonium
most
significant
contributors,
adding
14.3%
9.1%
In
realm
interplay
between
components,
especially
TNO3–RH
pair,
is
exceptionally
impactful,
constituting
58.1%
total
contribution
interactions.
summary,
this
illuminates
their
interplay,
suggesting
integration
statistical
methods
thermodynamic
models
enhanced
understanding
acidity
dynamics
future.
