Authorea (Authorea),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Nov. 14, 2023
Upscaling
flux
tower
measurements
based
on
machine
learning
(ML)
algorithms
is
an
essential
approach
for
large-scale
net
ecosystem
CO2
exchange
(NEE)
estimation,
but
existing
ML
upscaling
methods
face
some
challenges,
particularly
in
capturing
NEE
interannual
variations
(IAVs)
that
may
relate
to
lagged
effects.
With
the
capacity
of
characterizing
temporal
memory
effects,
Long
Short-Term
Memory
(LSTM)
networks
are
expected
help
solve
this
problem.
Here
we
explored
potential
LSTM
predicting
across
various
ecosystems
using
data
over
82
sites
North
America.
The
model
with
differentiated
plant
function
types
(PFTs)
demonstrates
capability
explain
79.19%
(R2
=
0.79)
monthly
within
testing
set,
RMSE
and
MAE
values
0.89
0.57
g
C
m-2
d-1
respectively
(r
0.89,
p
<
0.001).
Moreover,
performed
robustly
cross-site
variability,
67.19%
can
be
predicted
by
both
models
without
distinguished
PFTs
showing
improved
predictive
ability.
Most
importantly,
IAV
highly
correlated
observations
0.81,
0.001),
clearly
outperforming
random
forest
-0.21,
0.011).
Among
all
nine
PFTs,
solar-induced
chlorophyll
fluorescence,
downward
shortwave
radiation,
leaf
area
index
most
important
variables
explaining
variations,
collectively
accounting
approximately
54.01%
total.
This
study
highlights
great
improving
carbon
multi-source
remote
sensing
data.
The Science of The Total Environment,
Journal Year:
2023,
Volume and Issue:
912, P. 169477 - 169477
Published: Dec. 22, 2023
Terrestrial
ecosystem
in
the
Northern
Hemisphere
is
characterized
by
a
substantial
carbon
sink
recent
decades.
However,
inferred
from
atmospheric
CO2
data
usually
larger
than
process-
and
inventory-based
estimates,
resulting
release
or
near-neutral
exchange
tropics.
The
approach
known
to
be
uncertain
due
systematic
biases
of
coarse
transport
model
simulation.
Compared
coarse-resolution
inverse
estimate
at
4°
×
5°
using
GEOS-Chem
integrated
region
N.
America,
E.
Asia,
Europe
2015
2018,
annual
native
high-resolution
0.5°
0.625°
reduced
−3.0±0.08
gigatons
per
year
(GtC
yr−1)
−2.15±0.08
GtC
yr−1
prominent
more
during
non-growing
seasons.
major
reductions
concentrate
mid-latitudes
(20°N–45°N),
where
mean
land
sinks
China
USA
are
0.64±0.03
0.35±0.02
0.14±0.03
0.15±0.02
yr−1,
respectively.
tends
trap
both
uptake
signal
within
planetary
boundary
layer,
weaker
estimates
biosphere
seasonal
strength.
Since
strong
fossil
fuel
emissions
persistently
released
surface,
trapped
leads
stronger
uptakes.
These
results
suggest
that
inversion
with
accurate
vertical
meridional
urgently
needed
targeting
national
neutrality.
Accurate
national
terrestrial
net
ecosystem
exchange
estimates
are
crucial
for
the
global
stocktake.
Net
from
different
inversion
models
vary
greatly
at
scale,
and
relative
impacts
of
prior
fluxes
observations
on
these
inversions
remain
unclear.
Here
we
estimate
51
land
regions
2017-2019
period,
focusing
10
largest
countries,
using
12
biosphere
XCO2
retrievals
GOSAT
OCO-2
satellites
as
constraints.
The
average
uncertainty
reduction
countries
increases
37%
with
45%
to
50%
combined
observations,
indicating
a
trend
towards
robust
estimates.
At
finer
spatial
scales,
even
is
only
33%,
i.e.,
flux
dominates
This
finding
underscores
critical
importance
integrating
multi-source
refining
improve
accuracy
carbon
Choice
model
input
satellite
data
has
significant
impact
modelled
dioxide
its
associated
large
according
atmospheric
data.
Sustainability,
Journal Year:
2024,
Volume and Issue:
16(18), P. 7895 - 7895
Published: Sept. 10, 2024
The
capacity
of
carbon
sinks
varies
among
the
different
types
ecosystems,
and
whether
national
parks,
as
an
important
type
nature
reserve,
have
a
high
sink
(CSC)
eco-tourism
in
parks
affects
their
CSC
are
main
scientific
issues
discussed.
Using
MODIS
Net
Primary
Production
(NPP)
product
data,
this
study
analysed
spatiotemporal
variation
sources
(CSSs)
ecosystem
Huangshan
National
Park
from
2000
to
2020,
well
impact
tourism
on
these
sinks.
findings
indicate
that,
while
ecosystems
generally
strong
CSC,
they
may
not
always
function
sinks,
during
period,
served
source
for
four
years.
Temporally,
CSSs
park
exhibit
cyclical
pattern
change
with
four-year
cycle
seasonality,
spring
autumn
functioning
summer
winter
sources.
Spatially,
exhibited
vertical
band
spectrum
spatial
distribution,
showed
trend
gradual
enhancement
low
altitude
altitude.
Tourism
is
major
factor
that
has
ecosystems.
Authorea (Authorea),
Journal Year:
2023,
Volume and Issue:
unknown
Published: Nov. 14, 2023
Upscaling
flux
tower
measurements
based
on
machine
learning
(ML)
algorithms
is
an
essential
approach
for
large-scale
net
ecosystem
CO2
exchange
(NEE)
estimation,
but
existing
ML
upscaling
methods
face
some
challenges,
particularly
in
capturing
NEE
interannual
variations
(IAVs)
that
may
relate
to
lagged
effects.
With
the
capacity
of
characterizing
temporal
memory
effects,
Long
Short-Term
Memory
(LSTM)
networks
are
expected
help
solve
this
problem.
Here
we
explored
potential
LSTM
predicting
across
various
ecosystems
using
data
over
82
sites
North
America.
The
model
with
differentiated
plant
function
types
(PFTs)
demonstrates
capability
explain
79.19%
(R2
=
0.79)
monthly
within
testing
set,
RMSE
and
MAE
values
0.89
0.57
g
C
m-2
d-1
respectively
(r
0.89,
p
<
0.001).
Moreover,
performed
robustly
cross-site
variability,
67.19%
can
be
predicted
by
both
models
without
distinguished
PFTs
showing
improved
predictive
ability.
Most
importantly,
IAV
highly
correlated
observations
0.81,
0.001),
clearly
outperforming
random
forest
-0.21,
0.011).
Among
all
nine
PFTs,
solar-induced
chlorophyll
fluorescence,
downward
shortwave
radiation,
leaf
area
index
most
important
variables
explaining
variations,
collectively
accounting
approximately
54.01%
total.
This
study
highlights
great
improving
carbon
multi-source
remote
sensing
data.