SSRN Electronic Journal,
Journal Year:
2022,
Volume and Issue:
unknown
Published: Jan. 1, 2022
Light-absorbing
aerosols
(LAA),
including
black
carbon
(BC)
and
brown
(BrC),
profoundly
impact
regional
global
climate.
Vehicle
emission
is
an
important
source
of
LAA
in
urban
areas,
but
real-world
features
vehicular
are
not
fully
understood.
In
this
study,
traffic-related
BC
BrC
factors
(EFs)
their
inventories
were
evaluated
via
road
tunnel
observations
Tianjin,
China,
2017
2021.
The
distance-based
fuel-based
EFs
for
the
mixed
fleet
1.05
±
1.28
mg
km
−1
veh
0.057
g
(kg-fuel)
,
respectively,
2021,
with
a
dramatic
decrease
80.6%
compared
to
those
2017.
gasoline
vehicles
(GVs;
traditional
hybrid
vehicles)
diesel
(DVs)
0.55
0.065
10.5
2.52
Compared
2017,
also
decreased
significantly
by
10.8–53.6%,
0.32
0.45
0.018
0.020
EFs,
respectively.
GVs
DVs
0.091
0.024
3.06
0.91
annual
emissions
from
2021
have
been
reduced
10–69%
Tianjin.
479
tons
44.2
tons,
Although
account
small
amount
vehicle
population
(8.4%),
shares
83%
86%,
Our
study
indicates
significant
reduction
light-absorbing
due
pollution
prevention
control
China.
Journal of Geophysical Research Atmospheres,
Journal Year:
2022,
Volume and Issue:
127(16)
Published: Aug. 9, 2022
Abstract
Brown
carbon
(BrC)
has
been
recognized
as
an
important
contributor
to
global
warming
due
its
absorption
of
solar
radiation
with
strong
wavelength
dependence.
While
early
studies
mostly
consider
biomass
burning
a
major
emission
source,
few
recent
have
suggested
coal
combustion
and
vehicle
exhaust
contributors
BrC
emissions.
Considering
dominant
consumption,
large
residential
biofuel
usage,
the
increasing
number
vehicles,
pollution
could
result
in
remarkable
regional
climate
effects
China.
This
study
gives
overview
sources,
chemical
composition
properties
BrC,
focusing
on
categorization
measurement
techniques.
The
basic
features
China,
including
surface
concentrations,
column
burden,
sources
associated
absorbing
are
then
summarized
compared
other
countries.
emissions
well
optical
at
365
nm
from
primary
China
also
provide
more
straightforward
understanding
light‐absorbing
With
detailed
comparison
existing
publications,
deeper
insight
into
uncertainties
measurements
will
improve
effect
BrC.
review
recommends
key
research
areas
for
further
investigation
future.
Applied Sciences,
Journal Year:
2022,
Volume and Issue:
12(7), P. 3623 - 3623
Published: April 2, 2022
Airborne
particulate
matter
(PM)
is
a
pollutant
of
concern
not
only
because
its
adverse
effects
on
human
health
but
also
visibility
and
the
radiative
budget
atmosphere.
PM
can
be
considered
as
sum
solid/liquid
species
covering
wide
range
particle
sizes
with
diverse
chemical
composition.
Organic
aerosols
may
emitted
(primary
organic
aerosols,
POA),
or
formed
in
atmosphere
following
reaction
volatile
compounds
(secondary
SOA),
some
these
partition
between
gas
aerosol
phases
depending
upon
ambient
conditions.
This
review
focuses
carbonaceous
gaseous
precursors
by
road
traffic,
including
ultrafine
particles
(UFP)
polycyclic
aromatic
hydrocarbons
(PAHs)
that
are
clearly
linked
to
evolution
formation
species.
Clearly,
solid
fraction
has
been
reduced
during
last
two
decades,
implementation
after-treatment
systems
abating
approximately
99%
primary
mass
concentrations.
However,
role
brown
carbon
effect
climate
generation
nucleation
vapour
dilution
exhaust
remain
unclear
phenomena
will
need
further
investigation.
The
increasing
gasoline
vehicles
emissions
highlighted,
particularly
through
thermodynamic
gases
their
propensity
produce
particles.
remaining
carbon-containing
from
brakes,
tyres
wear
still
problem
even
future
full
electrification
vehicle
fleet.
Some
key
conclusions
recommendations
proposed
support
decision
makers
view
next
regulations
worldwide.
Environmental Science & Technology,
Journal Year:
2024,
Volume and Issue:
58(46), P. 20588 - 20597
Published: Nov. 7, 2024
The
linkages
between
BrC
optical
properties
and
chemical
composition
remain
inadequately
understood,
with
quantified
chromophores
explaining
less
than
25%
of
ambient
aerosol
light
absorption.
This
study
characterized
38
typical
in
aerosols
collected
Xi'an,
absorption
contributions
to
ranging
from
1.6
±
0.3
5.8
2.6%
at
365
nm.
Based
on
these
chromophores,
an
interpretable
machine
learning
model
the
Shapley
Additive
Explanation
(SHAP)
method
were
employed
explore
relationships
composition.
attained
high
accuracy
Pearson
correlation
coefficients
(
Research Square (Research Square),
Journal Year:
2025,
Volume and Issue:
unknown
Published: March 29, 2025
Abstract
Brown
carbon
(BrC)
holds
scientific
significance
by
influencing
radiative
balance,
cloud
condensation
dynamics,
and
regional
air
quality.
This
study
demonstrated
that
heavy-duty
diesel
vehicles
(HDDVs)
emit
substantially
higher
levels
of
light-absorbing
carbonaceous
aerosols
under
aggressive
conditions,
such
as
frequent
acceleration
high-speed
phases
investigating
the
emission
profiles,
formula
distribution,
chromophore
characteristics
various
driving
conditions.
A
non-targeted
analysis
BrC
was
performed
using
Fourier-transform
ion
cyclotron
resonance
mass
spectrometry
coupled
with
a
soft
electrospray
ionization
source.
The
light
absorption
properties
were
assessed
revealed
significantly
during
compared
to
low-speed
phases.
Formula
distribution
highlighted
substantial
presence
nitrogen-containing
species,
constituting
53-65%
identified
peaks,
high
O/N
ratios
(≥
3),
double
bond
equivalent
values
(DBE
>
10),
aromaticity
(Xc
≥
2.5),
which
indicated
contribution
aromatic
structures,
condensed
aromatics,
nitrooxy
functionalities
chromophores.
Journal of Geophysical Research Atmospheres,
Journal Year:
2025,
Volume and Issue:
130(11)
Published: May 28, 2025
Abstract
The
extensive
utilization
of
agricultural
machinery
in
China
has
made
it
a
prominent
contributor
to
particulate
matter
(PM).
However,
there
still
exist
significant
knowledge
gaps
understanding
optical
characteristics
and
molecular
composition
chromophores
brown
carbon
(BrC)
PM
emitted
from
machinery.
Therefore,
BrC
six
typical
machines
were
measured
investigate
the
light
absorption,
chromophore
characteristics,
influencing
factors.
Results
showed
that
average
emission
factors
methanol‐soluble
organic
(MSOC)
water‐soluble
(WSOC)
0.96
0.21
g
(kg
fuel)
−1
,
respectively,
exhibiting
clear
decreasing
trends
with
increasing
engine
power
improving
standards.
Despite
absorption
coefficient
methanol‐extracted
(Abs
365,M
)
being
approximately
2.2
times
higher
than
water
365,W
),
mass
efficiency
water‐extracted
(MAE
exhibited
significantly
greater
values
MAE
.
Among
detected
chromophores,
nitro‐aromatic
compounds
(NACs)
highest
contribution
was
about
14.5
more
total
compared
their
contributions
MSOC
(0.04%),
followed
by
polycyclic
aromatic
hydrocarbons
(PAHs)
oxygenated
PAHs
(OPAHs).
Besides,
integrated
simple
forcing
estimated
be
1.5
W
for
3.7
WSOC,
indicating
radiative
findings
this
study
not
only
provide
fundamental
data
climate
impact
estimation
but
also
propose
effective
strategies
mitigate
emissions,
such
as
enhancing
standards
promoting
adoption
high‐power
Aerosol and Air Quality Research,
Journal Year:
2023,
Volume and Issue:
23(5), P. 220329 - 220329
Published: Jan. 1, 2023
The
outbreak
of
COVID-19
pandemic
in
northern
Taiwan
led
to
the
implementation
Level
3
alert
measures
during
2021
and
thereby
impacted
air
quality
significantly,
which
provided
an
unprecedented
opportunity
better
understand
control
strategies
on
pollutants
future.
This
study
investigated
variations
sources,
chemical
characteristics
human
health
risks
PM2.5
comprehensively.
mass
concentrations
decreased
from
pre-alert
by
49.4%,
inorganic
ions,
i.e.,
NH4+,
NO3-
SO42-,
dropped
even
more
71%,
90%
52%,
respectively.
Nonetheless,
organic
matter
(OM)
elemental
carbon
(EC)
simply
36%
13%,
caused
composition
change
so
that
carbonaceous
dominated
instead
ions.
Correlation-based
hierarchical
clustering
analysis
further
showed
was
clustered
with
alert,
while
ions
both
post-alert
periods.
Moreover,
6
sources
were
identified
positive
matrix
factorization
(PMF),
secondary
nitrate
(i.e.,
aging
traffic
aerosols)
exhibited
most
significant
decrease
yet
primary
traffic-related
emissions,
matter,
changed
insignificantly.
implied
aerosols
could
be
easily
controlled
when
volume
declined,
source
needs
efforts
future,
especially
for
reduction
matter.
Therefore,
cleaner
energy
vehicles
is
still
needed.
Assessments
carcinogenic
risk
non-carcinogenic
induced
trace
elements
insignificant
decrease,
can
attributed
factories
did
not
shut
down
alert.
serves
as
a
metric
underpin
mitigation
pollution
future
highlights
importance
PM2.5.