Abstract.
Brown
carbon
(BrC)
is
a
fraction
of
Organic
Aerosols
(OA)
that
absorbs
radiation
in
the
ultraviolet
and
short
visible
wavelengths.
Its
contribution
to
radiative
forcing
uncertain
due
limited
knowledge
its
imaginary
refractive
index
(k
).
This
study
investigates
variability
k
for
OA
from
wildfires,
residential,
shipping,
traffic
emission
sources
over
Europe.
The
MONARCH
atmospheric
chemistry
model
simulated
concentrations
source
contributions,
feeding
an
offline
optical
tool
constrain
values
at
370
nm.
was
evaluated
against
mass
Aerosol
Chemical
Speciation
Monitors
(ACSM)
filter
sample
measurements,
aerosol
light
absorption
measurements
nm
derived
AethalometerTM
12
sites
across
Results
show
captures
temporal
environments
(regional,
suburban
urban
background).
Residential
emissions
are
major
colder
months,
while
secondary
organic
aerosols
(SOA)
dominate
warmer
periods.
Traffic
minor
primary
contributor.
Biomass
coal
combustion
significantly
influence
absorption,
with
shipping
also
notable
near
harbors.
Optimizing
revealed
significant
influenced
by
environmental
conditions.
Derived
biomass
burning
(0.03
0.13),
residential
(0.008
(0.005
0.08),
0.07)
improved
representation
compared
constant
k.
Introducing
such
source-specific
constraints
innovative
approach
enhance
models.
Atmospheric chemistry and physics,
Journal Year:
2025,
Volume and Issue:
25(4), P. 2667 - 2694
Published: Feb. 28, 2025
Abstract.
Brown
carbon
(BrC)
is
a
fraction
of
organic
aerosol
(OA)
that
absorbs
radiation
in
the
ultraviolet
and
short
visible
wavelengths.
Its
contribution
to
radiative
forcing
uncertain
due
limited
knowledge
its
imaginary
refractive
index
(k).
This
study
investigates
variability
k
for
OA
from
wildfires,
residential,
shipping,
traffic
emission
sources
over
Europe.
The
Multiscale
Online
Nonhydrostatic
Atmosphere
Chemistry
(MONARCH)
model
simulated
concentrations
source
contributions,
feeding
an
offline
optical
tool
constrain
values
at
370
nm.
was
evaluated
against
mass
chemical
speciation
monitors
(ACSMs)
filter
sample
measurements,
as
well
light
absorption
measurements
nm
derived
Aethalometer™
12
sites
across
Results
show
MONARCH
captures
temporal
environments
(regional,
suburban,
urban
background).
Residential
emissions
are
major
colder
months,
while
secondary
(SOA)
dominates
warmer
periods.
Traffic
minor
primary
contributor.
Biomass
coal
combustion
significantly
influence
absorption,
with
shipping
also
notable
near
harbors.
Optimizing
revealed
significant
influenced
by
environmental
conditions.
Derived
biomass
burning
(0.03
0.13),
residential
(0.008
(0.005
0.08),
0.07)
improved
representation
compared
constant
k.
Introducing
such
source-specific
constraints
innovative
approach
enhance
atmospheric
models.
Brown
carbon
(BrC)
from
biomass
burning
constitutes
a
significant
portion
of
light-absorbing
components
in
the
atmosphere.
Although
aging
BrC
surrogates
has
been
studied
many
laboratory
settings,
behavior
real-world
urban
environments
is
not
well
understood.
In
this
study,
through
combination
online
dynamic
monitoring
and
offline
molecular
characterization,
ambient
optical
was
linked
to
its
changes
composition.
Enhanced
light
absorption
by
consistently
observed
during
periods
dominated
oxygenated
organic
aerosol
(BBOA),
contrast
primary
emissions
or
secondary
formation
aqueous-phase.
This
enhancement
nitrogen-containing
compounds
BBOA.
Detailed
alongside
analysis
environmental
parameters,
revealed
that
an
increased
atmospheric
oxidizing
capacity,
marked
elevated
levels
ozone
nighttime
NO
Atmospheric chemistry and physics,
Journal Year:
2024,
Volume and Issue:
24(13), P. 7755 - 7772
Published: July 9, 2024
Abstract.
Water-insoluble
organic
carbon
(WIOC)
constitutes
a
substantial
portion
of
(OC)
and
contributes
significantly
to
light
absorption
by
brown
(BrC),
playing
pivotal
roles
in
climate
forcing.
China
is
hotspot
region
with
high
levels
OC
BrC,
but
information
regarding
the
sources
light-absorbing
properties
WIOC
on
national
scale
remains
scarce.
Here,
we
investigated
10
representative
urban
cities
China.
On
average,
made
up
33.4
±
7.66
%
40.5
9.73
concentrations
at
365
nm
(Abs365)
extractable
(EX-OC),
which
includes
relatively
hydrophobic
(WIOC
humic-like
substances,
HULIS-C)
hydrophilic
(non-humic-like
non-HULIS-C).
The
mass
efficiency
(MAE365)
was
(1.59
0.55
m2
(g
C)−1)
comparable
that
HULIS
(1.54
0.57
higher
than
non-HULIS
(0.71
0.28
C)−1),
indicating
possesses
stronger
capacity
OC.
Biomass
burning
(31.0
%)
coal
combustion
(31.1
were
dominant
WIOC,
exhibiting
strongest
capacity.
Moreover,
employing
simple
forcing
(SFE300–700
nm)
method,
observed
exhibited
highest
SFE300–700
(6.57
5.37
W
g−1)
among
EX-OC
fractions.
radiative
predominantly
contributed
–
39.4
15.5
39.5
12.1
%).
Considering
aromaticity,
sources,
atmospheric
processes
different
carbonaceous
components,
propose
continuum,
revealing
components
enriched
fossil
tend
possess
capacity,
aromatic
levels,
increased
molecular
weights,
greater
recalcitrance
atmosphere.
Reducing
fuel
emissions
emerges
as
an
effective
means
mitigating
both
gaseous
(CO2)
particulate
warming
components.
npj Climate and Atmospheric Science,
Journal Year:
2024,
Volume and Issue:
7(1)
Published: Nov. 22, 2024
Abstract
Ship
traffic
substantially
contributes
to
air
pollution,
thus
affecting
climate
and
human
health.
Recently
introduced
regulations
by
the
International
Maritime
Organization
(IMO)
on
fuel
sulfur
content
(FSC)
caused
a
shift
in
marine
onsumption
from
heavy
oils
(HFO)
diesel-like
distillate
fuels,
but
also
alternative
hybrid
fuels
operation
of
scrubbers.
Using
multi-wavelength
thermal-optical
carbon
analysis
(MW-TOCA),
our
study
provides
emission
factors
(EF)
carbonaceous
aerosol
particles
link
composition
features
observed
soot
microstructure,
which
may
be
exploited
online
monitoring
single-particle
mass
spectrometry
(SPMS).
Particulate
matter
absorbs
stronger
light
visible
UV
near-infrared
range
than
HFO.
However,
Simple
Forcing
Efficiency
(SFE)
absorption
weighted
EF
total
compensated
effect,
leading
net
reduction
>50%
when
changing
form
HFO
fuels.
Environment International,
Journal Year:
2024,
Volume and Issue:
195, P. 109185 - 109185
Published: Dec. 9, 2024
Carbonaceous
aerosols
(CA),
composed
of
black
carbon
(BC)
and
organic
matter
(OM),
significantly
impact
the
climate.
Light
absorption
properties
CA,
particularly
BC
brown
(BrC),
are
crucial
due
to
their
contribution
global
regional
warming.
We
present
(b
