Journal of Physical Oceanography,
Journal Year:
2022,
Volume and Issue:
unknown
Published: Aug. 29, 2022
Abstract
Previous
in-situ
observations
have
suggested
that
bottom
water
temperature
variations
in
shelf
seas
can
drive
significant
ocean
heat
flux
(BHF)
by
conduction.
The
BHF-driven
variations,
however,
been
overlooked
general
circulation
models.
In
this
study,
we
established
a
sea-sediment
fully
coupled
model
through
incorporating
the
BHF.
included
sediment
module/model,
and
BHF
was
calculated
based
on
content
variations.
Meanwhile,
applied
temporally
varying
calculation
of
temperature,
which
further
determined
temperature.
two-way
process
presents
more
complete
physically
reasonable
budget
synchronously
profile.
validated
using
one-dimensional
test
case,
then
it
domain
covering
Bohai
Yellow
Seas.
results
suggest
when
strong
thermocline
exists,
change
than
1°C
because
effects
are
limited
to
within
shallow
layer.
However,
column
is
well
mixed,
changes
entire
column,
transported
across
boundary
ventilated
atmosphere.
Thus,
has
less
effect
may
directly
affect
air-sea
flux.
interactions
dampen
amplitude
propose
calling
seabed
d
ampening
h
eat
variation
mechanism
(SDH).
Abstract.
Transport
and
cycling
of
dissolved
organic
carbon
(DOC)
are
most
active
in
estuaries.
However,
a
comprehensive
understanding
the
sources,
sinks,
transformation
processes
DOC
throughout
river-estuary-ocean
continuum
is
yet
to
be
derived.
Taking
Changjiang
Estuary
adjacent
shelf
sea
as
case
study
area,
this
applies
physics-biogeochemistry
coupled
model
investigate
continuum.
classified
into
two
types
depending
on
origin,
namely
terrigenous
(tDOC)
marine
(mDOC).
Simulation
results
were
compared
with
observation
showed
satisfactory
performance.
Our
indicates
that
summer,
distribution
driven
by
both
hydrodynamics
biogeochemical
processes,
while
winter,
it
primarily
hydrodynamics.
The
spatial
transition
from
terrigenous-dominated
marine-dominated
occurs
mainly
across
contour
line
salinity
20
PSU.
Additionally,
source-sink
patterns
summer
winter
significantly
different,
gradient
changes
chlorophyll-a
indicate
between
sources
sinks
DOC.
A
five-year
averaged
budget
analysis
has
capability
export
DOC,
tDOC
contributing
31
%
mDOC
accounting
for
69
%.
larger
proportion
attributed
local
processes.
offers
novel
perspective
holds
potential
its
application
future
other
Abstract.
Transport
and
cycling
of
dissolved
organic
carbon
(DOC)
are
most
active
in
estuaries.
However,
a
comprehensive
understanding
the
sources,
sinks,
transformation
processes
DOC
throughout
river-estuary-ocean
continuum
is
yet
to
be
derived.
Taking
Changjiang
Estuary
adjacent
shelf
sea
as
case
study
area,
this
applies
physics-biogeochemistry
coupled
model
investigate
continuum.
classified
into
two
types
depending
on
origin,
namely
terrigenous
(tDOC)
marine
(mDOC).
Simulation
results
were
compared
with
observation
showed
satisfactory
performance.
Our
indicates
that
summer,
distribution
driven
by
both
hydrodynamics
biogeochemical
processes,
while
winter,
it
primarily
hydrodynamics.
The
spatial
transition
from
terrigenous-dominated
marine-dominated
occurs
mainly
across
contour
line
salinity
20
PSU.
Additionally,
source-sink
patterns
summer
winter
significantly
different,
gradient
changes
chlorophyll-a
indicate
between
sources
sinks
DOC.
A
five-year
averaged
budget
analysis
has
capability
export
DOC,
tDOC
contributing
31
%
mDOC
accounting
for
69
%.
larger
proportion
attributed
local
processes.
offers
novel
perspective
holds
potential
its
application
future
other
Abstract.
Transport
and
cycling
of
dissolved
organic
carbon
(DOC)
are
most
active
in
estuaries.
However,
a
comprehensive
understanding
the
sources,
sinks,
transformation
processes
DOC
throughout
river-estuary-ocean
continuum
is
yet
to
be
derived.
Taking
Changjiang
Estuary
adjacent
shelf
sea
as
case
study
area,
this
applies
physics-biogeochemistry
coupled
model
investigate
continuum.
classified
into
two
types
depending
on
origin,
namely
terrigenous
(tDOC)
marine
(mDOC).
Simulation
results
were
compared
with
observation
showed
satisfactory
performance.
Our
indicates
that
summer,
distribution
driven
by
both
hydrodynamics
biogeochemical
processes,
while
winter,
it
primarily
hydrodynamics.
The
spatial
transition
from
terrigenous-dominated
marine-dominated
occurs
mainly
across
contour
line
salinity
20
PSU.
Additionally,
source-sink
patterns
summer
winter
significantly
different,
gradient
changes
chlorophyll-a
indicate
between
sources
sinks
DOC.
A
five-year
averaged
budget
analysis
has
capability
export
DOC,
tDOC
contributing
31
%
mDOC
accounting
for
69
%.
larger
proportion
attributed
local
processes.
offers
novel
perspective
holds
potential
its
application
future
other
Abstract.
Transport
and
cycling
of
dissolved
organic
carbon
(DOC)
are
most
active
in
estuaries.
However,
a
comprehensive
understanding
the
sources,
sinks,
transformation
processes
DOC
throughout
river-estuary-ocean
continuum
is
yet
to
be
derived.
Taking
Changjiang
Estuary
adjacent
shelf
sea
as
case
study
area,
this
applies
physics-biogeochemistry
coupled
model
investigate
continuum.
classified
into
two
types
depending
on
origin,
namely
terrigenous
(tDOC)
marine
(mDOC).
Simulation
results
were
compared
with
observation
showed
satisfactory
performance.
Our
indicates
that
summer,
distribution
driven
by
both
hydrodynamics
biogeochemical
processes,
while
winter,
it
primarily
hydrodynamics.
The
spatial
transition
from
terrigenous-dominated
marine-dominated
occurs
mainly
across
contour
line
salinity
20
PSU.
Additionally,
source-sink
patterns
summer
winter
significantly
different,
gradient
changes
chlorophyll-a
indicate
between
sources
sinks
DOC.
A
five-year
averaged
budget
analysis
has
capability
export
DOC,
tDOC
contributing
31
%
mDOC
accounting
for
69
%.
larger
proportion
attributed
local
processes.
offers
novel
perspective
holds
potential
its
application
future
other
Abstract.
Transport
and
cycling
of
dissolved
organic
carbon
(DOC)
are
most
active
in
estuaries.
However,
a
comprehensive
understanding
the
sources,
sinks,
transformation
processes
DOC
throughout
river-estuary-ocean
continuum
is
yet
to
be
derived.
Taking
Changjiang
Estuary
adjacent
shelf
sea
as
case
study
area,
this
applies
physics-biogeochemistry
coupled
model
investigate
continuum.
classified
into
two
types
depending
on
origin,
namely
terrigenous
(tDOC)
marine
(mDOC).
Simulation
results
were
compared
with
observation
showed
satisfactory
performance.
Our
indicates
that
summer,
distribution
driven
by
both
hydrodynamics
biogeochemical
processes,
while
winter,
it
primarily
hydrodynamics.
The
spatial
transition
from
terrigenous-dominated
marine-dominated
occurs
mainly
across
contour
line
salinity
20
PSU.
Additionally,
source-sink
patterns
summer
winter
significantly
different,
gradient
changes
chlorophyll-a
indicate
between
sources
sinks
DOC.
A
five-year
averaged
budget
analysis
has
capability
export
DOC,
tDOC
contributing
31
%
mDOC
accounting
for
69
%.
larger
proportion
attributed
local
processes.
offers
novel
perspective
holds
potential
its
application
future
other
Abstract.
Transport
and
cycling
of
dissolved
organic
carbon
(DOC)
are
most
active
in
estuaries.
However,
a
comprehensive
understanding
the
sources,
sinks,
transformation
processes
DOC
throughout
river-estuary-ocean
continuum
is
yet
to
be
derived.
Taking
Changjiang
Estuary
adjacent
shelf
sea
as
case
study
area,
this
applies
physics-biogeochemistry
coupled
model
investigate
continuum.
classified
into
two
types
depending
on
origin,
namely
terrigenous
(tDOC)
marine
(mDOC).
Simulation
results
were
compared
with
observation
showed
satisfactory
performance.
Our
indicates
that
summer,
distribution
driven
by
both
hydrodynamics
biogeochemical
processes,
while
winter,
it
primarily
hydrodynamics.
The
spatial
transition
from
terrigenous-dominated
marine-dominated
occurs
mainly
across
contour
line
salinity
20
PSU.
Additionally,
source-sink
patterns
summer
winter
significantly
different,
gradient
changes
chlorophyll-a
indicate
between
sources
sinks
DOC.
A
five-year
averaged
budget
analysis
has
capability
export
DOC,
tDOC
contributing
31
%
mDOC
accounting
for
69
%.
larger
proportion
attributed
local
processes.
offers
novel
perspective
holds
potential
its
application
future
other
Limnology and Oceanography,
Journal Year:
2024,
Volume and Issue:
unknown
Published: Nov. 15, 2024
Abstract
Dissolved
oxygen
(DO)
in
the
bottom
layer
is
essential
for
benthic
organisms,
and
its
temporal
variations
are
widely
concerned.
However,
previous
studies
have
primarily
focused
on
long‐term
of
DO,
leaving
high‐frequency
(HF)
dynamics
inadequately
understood.
This
study
addresses
this
gap
by
utilizing
two
seafloor
monitoring
systems
that
provide
3‐year‐long
HF
records
a
typical
temperate
shelf
sea,
Bohai
Sea,
China.
During
stratified
period
each
year,
DO
exhibits
notable
fluctuations
superimposed
seasonal
cycle.
These
signals
originate
from
tide‐induced
vertical
mixing,
showing
peaks
at
various
tidal
frequencies.
Notably,
significant
shallow‐water
observed
due
to
frequency
doubling
semi‐diurnal
diurnal
currents.
Moreover,
demonstrates
strongly
asymmetric
responses
mixing
time
scales.
To
be
specific,
increases
with
intensity
process
being
exceptionally
rapid
under
conditions
weak
mixing.
The
underlying
cause
asymmetry
markedly
stronger
gradient
near
seabed
sediment
demand.
A
process‐oriented
biological
model
successfully
reproduced
observational
features,
further
supporting
our
theoretical
inference.
findings
highlight
joint
role
demand
modulating
seas,
underscoring
their
significance
refined
prediction
future.
This
study
evaluates
deployment
strategies
for
artificial
oxygenation
devices
to
mitigate
coastal
hypoxia,
particularly
in
mariculture
regions.
Focusing
on
a
typical
region
the
waters
of
China,
we
examined
combined
effects
topography,
hydrodynamics,
and
biogeochemical
processes.
A
high-resolution
three-dimensional
physical-biogeochemical
coupled
model,
validated
against
observational
data
from
three
summer
cruises
2020,
accurately
captured
key
drivers
hypoxia.
Results
reveal
that
hypoxic
zones
exhibit
an
uneven
distribution,
driven
by
persistent
offshore
jets
at
specific
locations.
Nearshore
upstream
significantly
improves
oxygen
delivery
is
more
cost-efficient
due
reduced
construction
maintenance
requirements.
Uncertainty
analysis
explored
impacts
varying
water
mass
properties,
concentration,
injection
flow
rates,
content.
The
influence
varies
depending
site.
Particularly,
buoyant
plumes
can
notably
reduce
effectiveness
hypoxia
mitigation.
Artificial
may
lead
unintended
ecological
impacts,
including
increased
nutrient
release
enhanced
primary
production,
which
prolong
duration
Furthermore,
simulations
indicate
natural
downwelling
currents
are
insufficient
transport
oxygen-enriched
surface
bottom
zones.
These
findings
underscore
importance
comprehensive
predeployment
assessments
advancement
technologies
ensure
both
immediate
long-term
sustainability.
Biogeosciences,
Journal Year:
2024,
Volume and Issue:
21(23), P. 5435 - 5455
Published: Dec. 6, 2024
Abstract.
Transport
and
cycling
of
dissolved
organic
carbon
(DOC)
are
active
in
estuaries.
However,
a
comprehensive
understanding
the
sources,
sinks,
transformation
processes
DOC
throughout
river–estuary–ocean
continuum
is
yet
to
be
derived.
Taking
Changjiang
Estuary
adjacent
shelf
sea
as
case
study
area,
this
applies
physics–biogeochemistry
coupled
model
investigate
continuum.
classified
into
two
types
depending
on
origin,
namely
terrigenous
(tDOC)
marine
(mDOC).
Simulation
results
were
compared
with
observations
showed
satisfactory
performance.
Our
indicates
that
summer,
distribution
driven
by
both
hydrodynamics
biogeochemical
processes,
while
winter,
it
primarily
hydrodynamics.
The
spatial
transition
from
terrigenous-dominated
marine-dominated
occurs
mainly
across
contour
line
salinity
20
PSU.
Additionally,
source–sink
patterns
summer
winter
significantly
different,
gradient
changes
chlorophyll
indicate
between
sources
sinks
DOC.
A
5-year-averaged
budget
analysis
has
capability
export
DOC,
tDOC
contributing
31
%
mDOC
accounting
for
69
%.
larger
proportion
attributed
local
processes.
offers
novel
perspective
holds
potential
its
application
future
other
