GEOTRACES Reflections
Oceanography,
Год журнала:
2024,
Номер
37(2)
Опубликована: Янв. 1, 2024
GEOTRACES
is
an
international
program
that
has
benefited
from
contributions
by
investigators
in
35
nations.
The
mission
to
identify
processes
and
quantify
fluxes
control
the
distributions
of
key
trace
elements
isotopes
ocean
establish
sensitivity
these
changing
environmental
conditions.
This
perspective
first
summarizes
historical
motivation
for
program,
then
describes
selected
research
highlights,
focusing
on
recent
findings
related
iron.
patchy
distribution
iron
indicates
a
short
residence
time,
at
low
end
range
times
estimated
models.
Iron
removal
must,
therefore,
be
rapid.
Recent
results
North
Atlantic
Ocean
suggest
formation
particulate
authigenic
phases
may
factor
contributing
faster
than
previously
thought.
article
also
identifies
several
areas
where
advancements
are
expected
through
modeling
synthesis
efforts.
Язык: Английский
GEOTRACES: Ironing Out the Details of the Oceanic Iron Sources?
Oceanography,
Год журнала:
2024,
Номер
37(2)
Опубликована: Янв. 1, 2024
Dissolved
iron
(dFe)
is
an
essential
micronutrient
for
phytoplankton,
with
vanishingly
low
oceanic
dissolved
concentrations
(pico-
to
nanomoles
per
kg)
known
limit
growth—and
thus
influence
primary
productivity
and
carbon
cycling—over
much
of
the
surface
ocean.
However,
because
considerable
challenges
associated
contamination-free
sample
collection
accurate
analysis
such
dFe
concentrations,
first
reliable
measurements
came
only
in
1980s.
Further,
by
2003,
despite
several
decades
research,
there
were
~25
full-depth
profiles
worldwide,
dust
considered
be
main
source.
Since
2008,
facilitated
extensive
field
campaign
rigorous
intercalibration
international
GEOTRACES
program,
has
been
“explosion”
availability
data,
hundreds
now
available.
Concurrently,
a
paradigm
shift
view
marine
Fe
cycle
where
multiple
sources
contribute,
some
forms
can
transported
great
distances
through
intermediate
deep
Here,
we
showcase
datasets
across
different
ocean
basins,
synthesize
our
current
multi-source
cycle,
spotlight
sediments
as
important
source,
look
future
directions
constraining
boundary
exchange.
Язык: Английский
Marine biogenic humic substances control iron biogeochemistry across the Southern Ocean
Nature Communications,
Год журнала:
2025,
Номер
16(1)
Опубликована: Март 18, 2025
Abstract
Iron,
which
is
an
essential
element
for
marine
photosynthesis,
sparingly
soluble
in
seawater.
In
consequence,
iron
bioavailability
controls
primary
productivity
up
to
40%
of
the
world’s
ocean,
including
most
Southern
Ocean.
Organic
ligands
are
critical
maintaining
solution,
but
their
nature
largely
unknown.
Here,
we
use
a
comprehensive
dataset
electroactive
humics
and
iron-binding
contrasting
regions
across
Ocean
show
that
humic
substances
important
part
binding
ligand
pool,
as
has
been
found
elsewhere.
However,
demonstrate
mostly
produced
situ
composed
exopolymeric
from
phytoplankton
bacteria,
contrast
other
where
terrestrially-derived
suggested
play
major
role.
While
control
biogeochemistry,
cycling
surface
waters,
or
reprocessed
by
bacteria
affect
residence
time
at
scale
global
ocean.
Our
findings
indicate
autochthonous,
freshly
released
organic
matter
plays
role
controlling
ocean-climate
feedbacks
iron-limited
oceanic
regions.
Язык: Английский
Introduction to the special issue on twenty years of GEOTRACES: An international study of the marine biogeochemical cycles of trace elements and isotopes
Oceanography,
Год журнала:
2024,
Номер
37(2)
Опубликована: Янв. 1, 2024
This
special
issue
of
Oceanography
celebrates
the
transformational
findings
international
GEOTRACES
program
in
chemical
oceanography,
20
years
after
drafting
Science
Plan
2004
(GEOTRACES
Planning
Group,
2006).
With
section
cruise
phase
ending
soon,
and
a
planned
pivot
toward
smaller-scale
process
studies,
this
is
an
opportune
time
to
look
back
at
achievements
during
last
two
decades
highlight
some
advances
our
understanding
processes
that
determine
oceanic
distributions
trace
elements
isotopes
(TEIs).
Язык: Английский
Microbial strong organic-ligand production is tightly coupled to iron in hydrothermal plumes
Biogeosciences,
Год журнала:
2024,
Номер
21(22), С. 5233 - 5246
Опубликована: Ноя. 25, 2024
Abstract.
Hydrothermal
vents
have
emerged
as
important
sources
of
iron
to
seawater,
yet
only
a
subset
this
is
soluble
and
persists
long
enough
impact
the
deep-ocean
inventory.
The
longevity
solubility
in
seawater
part
governed
by
strong
organic
ligands
that
are
produced
microorganisms
ocean's
dissolved
iron-binding
ligand
pool.
Organic
been
recognized
support
elevated
hydrothermal
vent
plumes.
Siderophores
one
group
microbially
especially
high
binding
affinities
for
iron.
Here
we
present
first
direct
measurements
siderophore
concentrations
vents,
which
compare
bulk
concentrations,
along
1700
km
section
Mid-Atlantic
Ridge.
were
found
plumes
at
all
sites,
with
proximity
playing
an
role
dictating
type
diversity.
notable
presence
amphiphilic
siderophores
may
point
microbial
utilization
access
particulate
exchange
tight
coupling
between
within
neutrally
buoyant
across
distinct
environments,
well
siderophore-producing
genera,
suggests
biological
production
influences
chemistry
systems.
Язык: Английский