Frontiers in Remote Sensing,
Год журнала:
2022,
Номер
3
Опубликована: Окт. 21, 2022
Satellite
passive-microwave
instrumentation
has
allowed
the
monitoring
of
Arctic
sea
ice
over
past
43
years,
and
this
revealed
quantified
major
changes
occurring
in
coverage.
The
43-year
1979–2021
record
shows
considerable
interannual
variability
but
also
a
long-term
downward
trend
that
is
clear
from
many
vantage
points:
A
linear-least-square
−54,300
±
2,700
km
2
/year
for
yearly
average
extents;
statistically
significant
negative
trends
each
12
calendar
months;
nine
regions
into
which
cover
divided;
fact
all
months
highest
monthly
extent
came
first
8
years
lowest
last
10
record;
prominent
shortening
season
throughout
much
marginal
zone,
with
length
some
locations
decreasing
by
100
days
previously
experiencing
months-long
seasons
now
typically
no
longer
having
at
all.
overall,
Arctic-wide
value
extents
since
1979
consistently
had
magnitude
exceeding
two
standard
deviations
line
slope
1990
remained
narrow
range
−53,000
/yr
to
−55,500
2011.
Environmental Research Letters,
Год журнала:
2021,
Номер
16(4), С. 043002 - 043002
Опубликована: Янв. 14, 2021
Abstract
Pronounced
changes
in
the
Arctic
environment
add
a
new
potential
driver
of
anomalous
weather
patterns
midlatitudes
that
affect
billions
people.
Recent
studies
these
Arctic/midlatitude
linkages,
however,
state
inconsistent
conclusions.
A
source
uncertainty
arises
from
chaotic
nature
atmosphere.
Thermodynamic
forcing
by
rapidly
warming
contributes
to
events
through
changing
surface
heat
fluxes
and
large-scale
temperature
pressure
gradients.
But
internal
shifts
atmospheric
dynamics—the
variability
location,
strength,
character
jet
stream,
blocking,
stratospheric
polar
vortex
(SPV)—obscure
direct
causes
effects.
It
is
important
understand
associated
processes
differentiate
Arctic-forced
natural
variability.
For
example
early
winter,
reduced
Barents/Kara
Seas
sea-ice
coverage
may
reinforce
existing
teleconnections
between
North
Atlantic/Arctic
central
Asia,
downstream
East
Asia.
Reduced
sea
ice
Chukchi
Sea
can
amplify
ridging
high
near
Alaska,
influencing
across
America.
In
late
winter
southward
displacement
SPV,
coupled
troposphere,
leads
extremes
Eurasia
Combined
tropical
conditions
modulate
SPV.
Observational
evidence
for
linkages
continues
accumulate,
along
with
understanding
connections
pre-existing
climate
states.
Relative
variability,
loss
alone
has
played
secondary
role
linkages;
full
influence
amplification
remains
uncertain.
Annals of the New York Academy of Sciences,
Год журнала:
2021,
Номер
1504(1), С. 167 - 186
Опубликована: Июль 27, 2021
Abstract
We
analyze
the
polar
sea
ice
distribution
and
global
level
pressure
(SLP)
baroclinicity
distributions
over
“satellite”
period
of
1979–2020.
In
Arctic,
there
are
statistically
significant
extent
(SIE)
decreases
in
all
calendar
months,
annual
mean
has
lost
2.22
million
km
2
four
decades.
The
Antarctic
SIE,
marked
contrast,
increased
up
to
2014,
then
commenced
a
remarkable
retreat
(the
decreased
by
2.03
3
years
2017),
subsequently
near
its
long‐term
average
value
2020.
shifts
seasonal‐mean
SLP
patterns
consistent
with
warming
planet.
At
synoptic
scale,
we
diagnose
changes
baroclinicity,
mechanism
which
cyclones,
fronts,
other
weather
systems
generated.
Through
novel
presentation,
give
an
overview
relative
roles
vertical
shear
static
stability
influencing
trends
baroclinicity.
both
Arctic
regions,
is
shown
have
each
season
(with
sole
exception
summer).
This
increase,
coupled
midlatitude
results
poleward
storm
tracks.
Remote Sensing of Environment,
Год журнала:
2021,
Номер
267, С. 112753 - 112753
Опубликована: Окт. 22, 2021
The
multi-channel
satellite
passive-microwave
record
of
Earth's
sea
ice
coverage,
extending
back
to
the
late
1970s,
has
long
revealed
declining
coverage
in
Arctic
but
through
2015
an
overall
increase
rather
than
decrease
Antarctic
coverage.
Following
major
decreases
since
2015,
42-year
1979–2020
dataset
now
shows
recent
losses
both
hemispheres,
and
this
is
convincingly
demonstrated
by
enumeration
monthly
yearly
high
low
extents
experienced
over
course
42
years.
In
fact,
one
most
convincing
statistics
on
cover
fact
that
1986
not
a
single
extent
any
month
93
lows.
contrast,
all
12
calendar
months
have
their
period
2007–2015,
while
8
had
lows
2015.
Globally,
every
registered
new
within
past
5
These
results
are
complemented
(and
somewhat
tempered)
quantification
range
values
For
instance,
although
Arctic's
lowest
September
average
(in
2012)
53%
lower
its
highest
1980),
other
far
smaller
percent
differences
between
values.
extents,
value
2020)
18%
1982),
Antarctic's
2017)
16%
2014),
global
2019)
only
12%
1982).
Frontiers in Earth Science,
Год журнала:
2021,
Номер
9
Опубликована: Июль 1, 2021
Arctic
Amplification
is
a
fundamental
feature
of
past,
present,
and
modelled
future
climate.
However,
the
causes
this
“amplification”
within
Earth’s
climate
system
are
not
fully
understood.
To
date,
warming
in
has
been
most
pronounced
autumn
winter
seasons,
with
trend
predicted
to
continue
based
on
model
projections
Nevertheless,
mechanisms
by
which
will
take
place
numerous,
interconnected.
complex.
Will
be
primarily
driven
local,
within-Arctic
processes,
or
external
forces
play
greater
role
contributing
changing
region?
Motivated
uncertainty
climate,
review
seeks
evaluate
several
key
atmospheric
circulation
processes
important
ongoing
discussion
amplification,
focusing
troposphere.
Both
local
remote
drivers
amplification
considered,
specific
focus
given
high-latitude
blocking,
poleward
moisture
transport,
tropical-high
latitude
subseasonal
teleconnections.
Impacts
variability
transport
sea
ice,
ice
sheet
surface
mass
balance,
snow
cover,
other
cryospheric
variables
reviewed
discussed.
The
evolution
discussed
terms
projected
trends
blocking
their
coupling
cryosphere.
As
strongly
influenced
lower-latitude
state
tropical-to-Arctic
teleconnections
also
considered.
Journal of Climate,
Год журнала:
2021,
Номер
34(10), С. 3733 - 3749
Опубликована: Фев. 11, 2021
Abstract
For
the
last
few
decades
Northern
Hemisphere
midlatitudes
have
seen
an
increasing
number
of
temperature
extreme
events.
It
has
been
suggested
that
some
these
extremes
are
related
to
planetary
wave
activity.
In
this
study
we
identify
propagation
regions
at
300
hPa
using
ERA-Interim
dataset
from
1980
2017
and
link
them
in
densely
populated
Hemisphere.
Most
studies
used
background
flow
fields
monthly
or
seasonal
scale
investigate
propagation.
a
phenomenon
is
influenced
by
threshold
incidents
nonlinear
processes,
can
distort
net
Rossby
signal.
A
novel
aspect
our
investigation
lies
use
daily
data
allowing
it
be
diagnosed
for
limited
but
important
periods
across
wider
range
latitudes,
including
polar
region.
We
show
winter
associated
with
circulation
anomalies
both
Arctic
tropics,
while
relative
importance
areas
differs
according
specific
midlatitude
particular,
trains
connecting
tropical
Pacific
Atlantic
may
North
America
Siberia.
seas
markedly
Eurasian
regions.
Analysis
synoptic
suggests
pre-existing
local
play
key
role
development
those
extremes,
as
well
amplification
large-scale
trains.
also
demonstrate
warm
create
cold
outbreaks
Siberia
America.
