Abstract.
The
particle-phase
state
is
crucial
for
reactive
gas
uptake,
heterogeneous,
and
multiphase
chemical
reactions,
thereby
impacting
secondary
aerosol
formation.
This
study
provides
valuable
insights
into
the
significance
of
transition
liquid
water
(ALW)
in
winter
particulate
growth.
Our
findings
reveal
that
particles
predominantly
exist
as
semi-solid
or
solid
during
clean
days
with
ambient
relative
humidity
(RH)
below
30
%.
However,
non-liquid
to
phase
occurs
when
ALW
mass
fraction
exceeds
15
%
(dry
mass)
at
RH
thresholds
40–60
During
haze
episodes,
transformation
rates
sulfate
nitrate
aerosols
rapidly
increase
through
increased
by
48
11
%,
respectively,
resulting
noticeable
increases
inorganic
(SIA).
presence
abundant
ALW,
favored
elevated
higher
proportion
SIA,
facilitates
heterogeneous
aqueous
processes
particles,
leading
a
substantial
formation
organic
oxidation.
Consequently,
overall
hygroscopicity
parameters
exhibit
enhancement
mean
value
23
These
results
highlight
key
factor
initiating
positive
feedback
loops
between
episodes
over
North
China
Plain.
Accurate
predictions
necessitate
explicit
consideration
transport
models.
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(4), P. 2399 - 2414
Published: Feb. 26, 2024
Abstract.
The
particle
phase
state
is
crucial
for
reactive
gas
uptake,
heterogeneous,
and
multiphase
chemical
reactions,
thereby
impacting
secondary
aerosol
formation.
This
study
provides
valuable
insights
into
the
significance
of
particle-phase
transition
liquid
water
(ALW)
in
mass
growth
during
winter.
Our
findings
reveal
that
particles
predominantly
exist
a
semi-solid
or
solid
clean
winter
days
with
ambient
relative
humidity
(RH)
below
30
%.
However,
non-liquid
to
occurs
when
ALW
fraction
exceeds
15
%
(dry
mass)
at
RH
thresholds
40
%–60
During
haze
episodes,
transformation
rates
sulfate
nitrate
aerosols
rapidly
increase
through
increased
by
48
11
%,
respectively,
resulting
noticeable
increases
inorganic
(SIA).
presence
abundant
ALW,
favored
elevated
higher
proportion
SIA,
facilitates
partitioning
water-soluble
compounds
from
phase,
as
well
heterogeneous
aqueous
processes
particles.
leads
substantial
formation
organic
oxidation.
Consequently,
overall
hygroscopicity
parameters
exhibit
enhancement,
mean
value
23
These
results
highlight
key
factor
initiating
positive
feedback
loops
between
episodes
over
North
China
Plain.
Accurate
predictions
necessitate
explicit
consideration
transport
models.
Earth s Future,
Journal Year:
2024,
Volume and Issue:
12(1)
Published: Jan. 1, 2024
Abstract
Anthropogenic
dust
is
an
important
constituent
of
airborne
particles
in
the
urban
environment
but
its
ice
nucleation
activity
remains
poorly
investigated.
Here,
we
studied
sources
and
nucleating
properties
size‐resolved
atmosphere
under
mixed‐phase
cloud
conditions.
The
heat‐resistant
(INPs)
unexpectedly
contributed
∼70%
supermicron
INPs
at
temperatures
below
−15°C.
A
detailed
chemical
composition
analysis
revealed
that
these
were
associated
with
anthropogenic
dust,
such
as
traffic‐influenced
road
dust.
parameterization
based
on
was
developed
to
predict
INP
concentration,
given
their
correlations
concentration
similarity
compositions.
Once
integrated
into
global
models,
this
holds
potential
assess
contribution
a
scale.
Given
considerable
presence
significant
role
INPs,
suggest
it
may
be
aerosol
source
influencing
microphysics
warrant
further
investigations.
European Respiratory Review,
Journal Year:
2024,
Volume and Issue:
33(173), P. 230259 - 230259
Published: July 1, 2024
Particulate
matter
with
a
diameter
≤2.5
μm
(PM
2.5
)
poses
substantial
global
challenge,
growing
recognition
of
pathogens
contributing
to
diseases
associated
exposure
PM
.
Recent
studies
have
focused
on
,
which
impairs
the
immune
cells
in
response
microbial
infections
and
potentially
contributes
development
severe
respiratory
tract.
Accordingly,
changes
function
microecology
mediated
by
are
important
factors
that
enhance
risk
pathogenesis.
These
garnered
significant
interest.
In
this
review,
we
summarise
recent
potential
mechanisms
involved
-mediated
system
disruption
exacerbation
pathogenesis
We
also
discuss
crucial
areas
for
future
research
address
gaps
our
understanding
develop
effective
strategies
combat
adverse
health
effects
Environmental Science & Technology,
Journal Year:
2023,
Volume and Issue:
57(48), P. 20074 - 20084
Published: Nov. 17, 2023
Efflorescence
of
ammonium
nitrate
(AN)
aerosols
significantly
impacts
atmospheric
secondary
aerosol
formation,
climate,
and
human
health.
We
investigated
the
effect
representative
water-soluble
organic
compounds
(WSOCs)
(sucralose
(SUC),
glycerol
(GLY),
citric
acid
(CA)
on
AN:WSOC
efflorescence
using
vacuum
Fourier
transform
infrared
spectroscopy.
Combining
relative
humidity
(ERH)
measurements,
heterogeneous
nucleation
rates,
model
predictions,
we
found
that
viscosity,
correlating
with
molecular
diffusion,
effectively
predicted
ERH
variations
among
aerosols.
WSOCs
higher
viscosity
(SUC
CA)
hindered
efflorescence,
while
GLY
a
lower
showed
minor
effect.
At
low
AN:CA
molar
ratio
(10:1),
CA
promoted
ERH,
likely
due
to
crystallization.
Increasing
droplet
pH
inhibited
efflorescence.
In
contrast,
for
AN:SUC
AN:GLY
aerosols,
is
pH-insensitive.
With
addition
trivial
sulfate,
droplets
exhibited
two-stage
coinciding
sulfate
AN
Given
abundance,
morphology,
phase,
mixing
state
are
significant
chemistry
physics.
Our
results
suggest
AN:WSOCs
can
exist
in
amorphous
phase
atmosphere,
behavior
depending
composition,
pH,
cation
anion
interactions
complex
manner.
Abstract.
Aerosol
hygroscopic
growth
and
activation
under
high
relative
humidity
(RH)
conditions
significantly
influence
the
physicochemical
properties
of
submicron
aerosols
(PM1).
However,
this
process
remains
poorly
characterized
due
to
limited
measurements.
To
address
gap,
we
deployed
an
advanced
aerosol-fog
sampling
system
that
automatically
switched
between
PM1,
PM2.5,
TSP
inlets
at
a
rural
site
in
North
China
Plain
cold
season.
The
results
revealed
aerosol
swelling
water
vapor
uptake
influenced
RH
by
shifting
cut-off
size
impactors.
Under
subsaturated
(>
90
%),
over
25
%
mass
with
dry
diameters
below
1
μm
resided
supermicron
ranges,
while
supersaturated
foggy
conditions,
more
than
70
migrated
ranges.
Hygroscopic
particularly
affected
highly
hydrophilic
inorganic
salts
significant
sulfate
nitrate
particles
27
–
33
95
≤
99
%,
65.5
conditions.
Moreover,
10
biomass
burning
organic
grew
beyond
2.5
during
fog
events,
fossil
fuel-related
OA
(FFOA)
remained
dominantly
suggesting
inefficient
aqueous
conversion
FFOA.
two
SOA
factors
(OOA1
OOA2)
behaved
differently
OOA2
exhibiting
higher
activated
fraction
despite
lower
oxygen-to-carbon
ratio.
A
substantial
increase
organosulfur
concentrations
droplets
events
suggested
conversions
formations
brown
carbon
potential
radiative
impacts.
Overall,
our
study
highlights
remarkably
different
processing
primary
secondary
PM1
components
distinct
ambient
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(9), P. 5625 - 5636
Published: May 15, 2024
Abstract.
Cooking
organic
aerosol
(COA)
is
one
of
the
major
constituents
particulate
matter
in
urban
areas.
COA
oxidized
by
atmospheric
oxidants
such
as
ozone,
changing
its
physical,
chemical
and
toxicological
properties.
However,
lifetimes
tracers
oleic
acid
are
typically
longer
than
those
that
have
been
estimated
laboratory
studies.
We
tackled
issue
considering
temperature.
Namely,
we
hypothesize
increased
viscosity
at
ambient
temperature
accounts
for
prolonged
wintertime.
Laboratory-generated
particles
from
cooking
oil
were
exposed
to
ozone
an
flow
tube
reactor
range
−20
35
°C.
The
pseudo-second-order
reaction
rate
constants
(k2)
experimental
data
assuming
a
constant
concentration
tube.
values
k2
decreased
orders
magnitude
lower
temperatures.
dependence
was
fit
well
diffusion-limited
mechanism.
result
suggested
likely
key
factor
account
decrease
reactivity
reduced
range,
though
idea
will
still
need
be
verified
temperature-dependent
future.
In
combination
with
observed
global
surface
temperature,
much
wintertime
(>
1
h)
summertime
(a
few
minutes)
temperate
boreal
regions.
Our
present
study
demonstrates
oxidation
parameterized
function
future
estimating
environmental
impacts
fates
this
category
matter.
