Optics Express,
Journal Year:
2024,
Volume and Issue:
32(15), P. 25644 - 25644
Published: June 19, 2024
High
optical
complexity
caused
by
the
variability
of
marine
particles
poses
a
major
challenge
to
development
bio-optical
algorithms
for
particulate
organic
carbon
(POC)
concentration
retrievals
from
measurements
in
coastal
waters.
Here,
we
developed
particle
composition-specific
approach
estimate
POC
off
areas
Guangdong
and
eastern
Hainan
Island,
China.
The
ratio
phytoplankton
absorption
detritus
coefficient
aph(443)/ad(443)
was
used
optically
discriminate
water
types.
samples
with
≤
4.9
showed
significant
correlation
between
line
height
at
676
nm
aLH(676)
(R2
=
0.75,
n
70,
p
<
0.01).
In
contrast,
aph-dominant
>
had
high
covariance
scattering
675
bp(675)
0.85,
37,
Validation
an
independent
dataset
yielded
small
positive
bias
0.81,
APD
23.10%,
RMSE
29.01
mg
m
Frontiers in Marine Science,
Journal Year:
2023,
Volume and Issue:
10
Published: Feb. 21, 2023
Few
studies
have
incorporated
the
tools
of
stable
isotopes
and
optical
properties
to
study
biogeochemical
process
organic
matter
(OM),
including
particulate
(POM)
dissolved
(DOM),
which
prevents
our
comprehension
interactions
between
POM
DOM
in
marine
environment.
In
this
study,
origin,
distribution,
fate
Tieshangang
Bay,
a
weak
dynamic
bay
were
investigated
by
measuring
δ
13
C
15
N
POM,
carbon
(DOC),
absorption
fluorescence
(CDOM
FDOM).
upper
bay,
source
was
mainly
originated
from
terrestrial
discharge,
whereas
high
index
(FI)
indicated
that
external
aquatic
organism
activity
dominated
sources.
contrast,
outer
slightly
increased
enriched
enhanced
intensities
protein-like
components
considerable
contributions
situ
biological
activities
OM.
A
net
addition
DOC
occurred
both
bays.
The
decomposition
responsible
for
due
dynamics
primary
production
strong
freshly
produced
jointly
contributed
bay.
Our
suggests
hydrodynamics
regulate
biogeochemistry
Frontiers in Earth Science,
Journal Year:
2023,
Volume and Issue:
11
Published: Aug. 17, 2023
Sedimentary
organic
matter
(SOM)
on
continental
slopes
in
marine
regions
can
sensitively
record
climatic
and
environmental
changes.
In
this
study,
total
carbon
content
(TOC),
nitrogen
(TN),
their
stable
isotope
compositions
(δ
13
C
δ
15
N)
for
sediments
of
core
G02
were
investigated
(at
∼24.2-year
resolution)
to
reveal
the
temporal
variations
sources
main
controls
distribution
buried
northwestern
slope
South
China
Sea
over
last
∼8600
years.
Results
a
binary
mixing
model
that
∼82.3
±
3%
SOM
is
derived
from
autochthonous
sources.
We
suggest
contents
are
governed
by
distinct
factors.
The
more
positive
N
values
before
Pulleniatina
Minimum
Event
occurrence
ascribed
stronger
subsurface
water
intrusion
Kuroshio
Current,
which
led
enhanced
denitrification
turn
counteracted
effect
with
surface
caused
East
Asian
winter
monsoon.
show
fluctuant
decrease
during
ca.
8.6–3.0
cal
kyr
BP
conspicuous
increase
3.0–1.4
BP.
These
changes
attributed
productivity
induced
continuous
weakening
monsoon
terrigenous
input
weakened
Indian
summer
precipitation,
respectively.
Since
1.4
BP,
human
activities
have
become
dominant
factor
controlling
production
carbon.
results
provide
an
important
basis
understanding
source-sink
processes
factors
influencing
these
low-latitude
marginal
seas.
Remote Sensing,
Journal Year:
2023,
Volume and Issue:
15(15), P. 3768 - 3768
Published: July 28, 2023
The
source
information
of
coastal
particulate
organic
carbon
(POC)
with
high
spatial
and
temporal
resolution
is
great
significance
for
the
study
marine
cycles
biogeochemical
processes.
Over
past
decade,
satellite
ocean
color
remote
sensing
has
greatly
improved
our
understanding
spatiotemporal
dynamics
concentrations.
However,
due
to
complexity
POC
sources,
methods
sources
have
not
yet
been
established.
With
an
attempt
fill
gap,
this
developed
algorithm
retrieving
using
geochemical
isotope
technology.
end-member
mixing
model
was
used
calculate
proportion
response
relationship
between
in
situ
reflectance
(Rrs)
established
develop
a
retrieval
following
four
bands:
(Rrs(443)/Rrs(492))
×
(Rrs(704)/Rrs(665)).
results
showed
that
four-band
performed
well
R2,
mean
absolute
percentage
error
(MAPE)
root
square
(RMSE)
values
0.78,
33.57%
13.74%,
respectively.
Validation
against
data
derived
calculated
accurately,
MAPE
RMSE
27.49%
13.58%,
accuracy
verified
based
on
Sentinel-2
data,
28.02%
15.72%,
Additionally,
we
found
higher
outside
Zhanjiang
Bay
than
inside
it
survey
which
consistent
retrieved
results.
Influencing
factors
may
be
occurrence
phytoplankton
blooms
bay
impact
terrestrial
inputs
bay.
Remote
combination
isotopes
provides
important
technical
assistance
comprehending
process
uncovering
variations
their
underlying
causes.
Water,
Journal Year:
2022,
Volume and Issue:
14(6), P. 899 - 899
Published: March 13, 2022
Mangroves
growing
in
intertidal
areas
are
faced
with
various
stresses
caused
by
coastal
human
activities
and
oceanic
atmospheric
sources.
Although
the
study
of
physiological
biochemical
characteristics
mangroves
has
been
developing
over
past
four
decades,
effect
upwelling
on
plants
stress
resistance
seldom
investigated.
Here,
changes
leaves
Kandelia
obovata
seedlings
response
to
were
investigated
(air
temperature:
25
°C;
water
control
°C,
13
5
salinity:
10‰).
The
results
revealed
that
treatment
an
increase
chlorophyll
content
but
a
decrease
photosynthetic
fluorescence
parameters.
Hydrogen
peroxide
(H2O2)
production
malondialdehyde
activity
(MDA)
increased
temperature.
proline
under
stress,
whereas
soluble
sugar
decreased.
Further,
antioxidant
enzymes,
such
as
superoxide
dismutase
(SOD)
peroxidase
(POD),
showed
increasing
trend
during
treatment,
while
catalase
(CAT)
It
was
evidenced
triggered
responses
seedlings.
This
became
more
intense
temperature
decreased,
all
these
indicators
different
stress.
Through
synthesizing
energy
regulating
enzyme
osmotic
pressure,
K.
formed
mechanism
short-term
upwelling.
