Atmospheric chemistry and physics,
Journal Year:
2025,
Volume and Issue:
25(4), P. 2423 - 2442
Published: Feb. 25, 2025
Abstract.
Extensive
industrial
operations
in
the
Athabasca
oil
sands
region
(AOSR)
(Alberta,
Canada)
are
a
suspected
source
of
water-soluble
brown
carbon
(WS-BrC),
class
light-absorbing
organic
aerosols
capable
altering
atmospheric
solar-radiation
budgets.
However,
current
understanding
WS-BrC
across
AOSR
is
limited,
and
primary
regional
sources
these
unknown.
During
summer
2021,
active
filter-pack
samplers
were
deployed
at
five
sites
to
collect
total
suspended
particulate
matter
for
purpose
evaluating
WS-BrC.
Ultraviolet–visible
spectroscopy
fluorescence
excitation–emission
matrix
(EEM)
spectroscopy,
complemented
by
parallel
factor
analysis
(PARAFAC)
modelling,
employed
sample
characterization.
Aerosol
absorbance
was
comparable
between
near-industry
remote
field
sites,
suggesting
that
exerted
limited
influence
on
radiative
forcing.
The
combined
EEM–PARAFAC
method
identified
three
fluorescent
components
(fluorophores),
including
one
humic-like
substance
(C1)
two
protein-like
substances
(C2
C3).
Sites
near
facilities
exposures
receiving
transport
from
local
industry
(as
indicated
back-trajectory
analysis)
displayed
increased
C1
C3
fluorescence;
moreover,
both
fluorophores
positively
correlated
with
elements
(i.e.
vanadium
sulfur)
gaseous
pollutants
nitrogen
dioxide
reduced
sulfur),
indicative
emissions.
C2
fluorophore
exhibited
high
emission
intensity
near-field
during
severe
wildfire
smoke
events,
while
positive
correlations
indicator
variables
suggest
likely
reflected
wildfire-generated
anthropogenic
These
results
demonstrate
an
accessible
cost-effective
tool
can
be
applied
monitor
AOSR.
Atmospheric chemistry and physics,
Journal Year:
2025,
Volume and Issue:
25(6), P. 3647 - 3667
Published: March 27, 2025
Abstract.
To
understand
the
spatial
variation
of
optical
and
structural
properties
water-soluble
brown
carbon
its
influencing
factors
in
China,
light
absorption,
fluorescence,
Fourier
transform
infrared
(FTIR)
spectrum
organic
(WSOC)
different
regions
China
are
measured
following
same
analytical
methods.
The
average
absorption
coefficients
mass
efficiencies
WSOC
at
365
nm
(Abs365
MAE365)
rank
from
high
to
low
as
northwest
>
southwest
north
east
regional
site,
with
higher
values
northern
than
southern
sites
inland
areas
coastal
areas.
resolved
by
spectra-based
positive
matrix
factorization
model
abundance
aromatic
O−H
C=C
functional
groups
determined
FTIR
both
indicate
that
compounds
significant
light-absorbing
substances
have
a
impact
on
fluorophores.
Multiple
linear
regression
analysis
shows
fluorophores
identified
fluorescence
spectra
combined
parallel
factor
(PARAFAC)
contribute
about
62
%–93
%
all
sites,
which
humic-like
substance
(HULIS)
contributes
most,
especially
highly
oxygenated
HULIS
(29
%–50
%)
long
emission
wavelengths.
Combustion
source
emissions
atmospheric
chemical
processes
impacts
some
sites.
Moreover,
relative
humidity
(RH)
can
also
affect
MAE365
WSOC,
decreasing
increase
RH
when
RH<60
remaining
relatively
unchanged
RH>60
%.
Taken
together,
this
study
promotes
better
understanding
heterogeneity
their
China.
