Abstract.
Previous
measurement-model
comparisons
of
atmospheric
isoprene
levels
showed
a
significant
unidentified
source
in
some
northern
Chinese
cities
during
winter.
Here,
spatial
variability
winter
aerosol
organosulfate
(OS)
formation
typical
southern
(Guangzhou
and
Kunming)
(Xi’an
Taiyuan)
cities,
China,
was
investigated
to
reveal
the
influence
potential
non
biogenic
contributor
on
OS
pollution
levels.
Monoterpene-derived
OSs
were
significantly
higher
than
which
attributed
temperature
dependent
emission
monoterpenes
(i.e.,
temperatures
drove
more
monoterpene
emissions).
However,
isoprene-derived
(OSi)
opposite
trend,
with
cities.
Principal
component
analysis
combined
field
simulation
combustion
experiments
suggested
that
biomass
burning
rather
gasoline,
diesel,
coal
contributed
abundance
OSi
The
comparison
anthropogenic
molecular
characteristics
between
particles
released
from
various
sources
ambient
stronger
fossil
fuel
activities
promoted
OSs.
Overall,
this
study
provides
direct
evidence
for
first
time
can
contribute
China
Journal of the American Chemical Society,
Journal Year:
2024,
Volume and Issue:
146(15), P. 10407 - 10417
Published: April 4, 2024
Nitroaromatic
compounds
are
major
constituents
of
the
brown
carbon
aerosol
particles
in
troposphere
that
absorb
near-ultraviolet
(UV)
and
visible
solar
radiation
have
a
profound
effect
on
Earth's
climate.
The
primary
sources
include
biomass
burning,
forest
fires,
residential
burning
biofuels,
an
important
secondary
source
is
photochemistry
aqueous
cloud
fog
droplets.
Nitrobenzene
smallest
nitroaromatic
molecule
model
for
photochemical
behavior
larger
compounds.
Despite
obvious
importance
its
droplet
to
atmospheric
environment,
there
not
been
any
detailed
studies
ultrafast
dynamics
nitrobenzene
solution.
Here,
we
combine
femtosecond
transient
absorption
spectroscopy,
time-resolved
infrared
quantum
chemistry
calculations
investigate
steps
following
near-UV
(λ
≥
340
nm)
photoexcitation
nitrobenzene.
To
understand
role
surrounding
water
molecules
nitrobenzene,
compare
results
these
investigations
with
analogous
measurements
solutions
methanol,
acetonitrile,
cyclohexane.
We
find
vibrational
energy
transfer
environment
quenches
internal
excitation,
therefore,
unlike
gas
phase,
do
observe
evidence
formation
photoproducts
timescales
up
500
ns.
also
hydrogen
bonding
between
slows
S1/S0
conversion
process.
Journal of Geophysical Research Atmospheres,
Journal Year:
2025,
Volume and Issue:
130(1)
Published: Jan. 4, 2025
Abstract
The
roles
of
organosulfur
compounds
(OSCs),
an
important
component
in
organic
matter,
brown
carbon
(BrC)
aerosol
absorption
is
often
overlooked.
Here,
the
molecular
composition
OSCs
and
its
associations
with
methanol‐soluble
BrC
(MS‐BrC)
during
a
haze
event
North
China
were
revealed
using
Fourier
transform
ion
cyclotron
resonance
mass
spectrometry
analysis.
By
combining
aggregated
boosted
tree
model
partial
least
squares
regression
estimation,
our
results
suggested
that
mainly
composed
potential
aromatic
structures,
MS‐BrC
was
closely
related
to
OSCs.
Specifically,
contribute
notable
26%
total
number
upper
limit
10.4%
absorption.
Furthermore,
we
found
influenced
by
coal
combustion,
desulfurization
reactions
showed
variations
Since
residential
combustion
(an
primary
source
OSs)
major
energy
China,
research
underscores
as
tracers
for
assessing
impact
fossil
fuel
on
highlights
atmospheric
influences
(e.g.,
light
health),
which
need
more
works
uncover
origins,
fates,
environmental
effects
Nitrogen-containing
organic
compounds
(NOCs)
in
frost
serve
as
a
critical
pathway
for
atmospheric
nitrogen
deposition,
significantly
impacting
the
biogeochemical
cycles
of
nitrogen.
However,
molecular
characteristics
NOCs
and
their
deposition
fluxes
are
scarcely
studied.
In
this
work,
samples,
collected
rural
Northeast
China
winter
2023,
were
analyzed
using
nontargeted
ultrahigh
performance
liquid
chromatography-orbitrap
mass
spectrometry
(UHPLC-Orbitrap
MS)
to
reveal
content
nitrogen-containing
explore
wet
fluxes.
The
average
number
assigned
formulas
lager
on
hazy
days
compared
nonhazy
both
water-soluble
(WSOM)
water-insoluble
matter
(WISOM)
(3114
vs.
1934
WSOM
3042
2224
WISOM
electrospray
ionization
(ESI−);
6921
5954
6629
5547
ESI+).
Specifically,
proportions
CHON
35.6–49.9%
(724–1517)
47–51.1%
(2686–3388)
ESI–
ESI+
modes,
respectively.
Nitrophenol
(C6H5NO3)
methyl
nitrophenol
(C7H7NO4)
most
abundant
NOCs,
with
(at
maximum
concentrations)
22.2
21.2
μg
m–2·h–1,
On
days,
reached
up
1.73
times
that
indicating
significant
ambient
during
haze
episode.
This
flux
positively
correlated
PM2.5
concentration,
implying
important
role
particulates
influencing
NOC
through
frost.
These
findings
highlight
susceptibility
capturing
from
atmosphere,
potentially
cycling
ecosystems.
While
biomass
burning
(BB)
is
the
largest
source
of
fine
particles
in
atmosphere,
influence
relative
humidity
(RH)
and
photochemistry
on
BB
secondary
organic
aerosol
(BB-SOA)
formation
aging
remains
poorly
constrained.
These
effects
need
to
be
addressed
better
capture
comprehend
evolution
BB-SOA
atmosphere.
Cresol
(C7H8O)
used
as
a
proxy
investigate
these
effects.
It
emitted
directly
from
has
been
identified
significant
SOA
precursor
residential
wood-burning
emissions.
The
gas-
particle-phase
signal
intensities
are
investigated
using
online
mass
spectrometers.
An
increase
yield
7%
observed
when
RH
rises
0.5–20
70–87%.
At
elevated
RH,
nitrogen-containing
compounds
due
processes.
This
linked
net
decrease
viscosity,
enabling
formed
greater
extent
at
presence
nitrogen
oxides.
results
highlight
importance
particle
water
content
for
molecular
compounds.
Journal of Geophysical Research Atmospheres,
Journal Year:
2025,
Volume and Issue:
130(3)
Published: Feb. 6, 2025
Abstract
Brown
carbon
(BrC)
is
known
to
have
a
great
impact
on
atmospheric
radiative
forcing,
but
its
absorption
characteristics
at
the
molecular
level
not
well
understood.
This
study
investigated
seasonal
variations
of
light
and
composition
BrC
in
Xi'an,
China.
Results
showed
that
exhibited
higher
capacity
cold
(autumn
winter)
than
warm
seasons
(spring
summer).
Nitrogen‐containing
organic
compounds
were
identified
as
important
chromophores.
Oxidized‐N
originated
from
biomass
burning
emissions
NO
x
/NO
3
−
mediated
oxidation
reactions
predominant
seasons,
whereas
reduced‐N
mainly
formed
NH
/NH
4
+
abundant
seasons.
These
results
contribute
better
understanding
formation
mechanisms
nitrogen‐containing
chromophores
PM
2.5
.
Atmospheric chemistry and physics,
Journal Year:
2025,
Volume and Issue:
25(5), P. 2967 - 2978
Published: March 12, 2025
Abstract.
Previous
measurement–model
comparisons
of
atmospheric
isoprene
levels
showed
a
significant
unidentified
source
in
some
northern
Chinese
cities
during
winter.
Here,
spatial
variability
winter
aerosol
organosulfate
(OS)
formation
typical
southern
(Guangzhou
and
Kunming)
(Xi'an
Taiyuan)
cities,
China,
was
investigated
to
reveal
the
influence
potential
non-biogenic
contributor
on
OS
pollution
levels.
Monoterpene-derived
OSs
were
significantly
higher
than
which
attributed
temperature-dependent
emission
monoterpenes
(i.e.,
temperatures
drove
more
monoterpene
emissions).
However,
isoprene-derived
(OSi)
opposite
trend,
with
cities.
Principal
component
analysis
combined
field
simulation
combustion
experiments
suggested
that
biomass
burning
rather
gasoline,
diesel,
coal
contributed
abundance
OSi
The
comparison
anthropogenic
molecular
characteristics
between
particles
released
from
various
sources
ambient
stronger
fossil
fuel
activities
promoted
considerable
OSs.
Overall,
this
study
provides
direct
evidence
for
first
time
can
contribute
China
