Julienne Stroeve discusses the need for improved forecasting of changing sea ice conditions months to years in advance. She notes that summer sea ice has been declining rapidly, opening new shipping routes in the Arctic. However, forecasts have large uncertainties and are needed at shorter time scales and with higher spatial resolution. Improving processes like melt ponds and ocean upwelling in models could enhance forecasts, as could initializing forecasts with ice thickness maps. A dedicated polar prediction effort like the proposed Year of Polar Prediction could bring together international experts to advance this important area.

1. Forecasting changing sea
ice conditions months to
years in advance
Julienne Stroeve
Senior Scientist National Snow and Ice Data
Center
September 30, 2015
State of the Arctic

2. UCAR Congressional Briefing – September 2015
State of the Arctic
Accelera'ng
ice
loss
Modern Satellite Era
Various ship, aircraft, early satellite,
in situ data, whaling ship log reports
Average
summer
ice
loss
from
1850-­‐2015
=
-­‐19,357
km2
yr-­‐1
Average
summer
ice
loss
from
1979
to
2015:
-­‐83,090
km2
yr-­‐1

3. UCAR Congressional Briefing – September 2015
State of the Arctic
Shipping
routes
are
opening
August
22,
2007
Northern
Sea
Route
NSR
open
since
2008
NWP
open
most
years
since
2007

4. UCAR Congressional Briefing – September 2015
State of the Arctic
Probability
that
the
Northern
Sea
Route
will
be
ice
free
80%
Ice-­‐Free
50%
Ice-­‐Free
Russia
Murmansk
Using
the
NSR,
ships
can
reduce
the
distance
between
Europe
and
Asia
by
40%

5. Increasing
need
for
shorter-­‐term
predic'ons
Median
PredicCon
Spread
in
PredicCons
Observed
Ice
CondiCons

6. UCAR Congressional Briefing – September 2015
State of the Arctic
Need
for
predic'ng
spa'al
distribu'on
of
ice
condi'ons
NCAR
NASA
NOAA
University
of
Washington
NSIDC
Probability
of
Ice
(0-­‐100%)
0
20
40
60
80
100%
Observed
ice
edge
in
2014

7. UCAR Congressional Briefing – September 2015
State of the Arctic
How
to
improve
seasonal
forecasts?
• We
also
need
a
beVer
understanding
of
important
processes
such
as
melt
ponds
and
ocean
upwelling.
• Having
the
necessary
observa'ons
to
ini'alize
the
forecasts.
For
example
maps
of
ice
thickness
are
cri'cally
needed.

8. UCAR Congressional Briefing – September 2015
State of the Arctic
• A
dedicated
polar
predic'on
effort
is
needed.
• The
proposed
Year
of
Polar
Predic'on
(YOPP)
from
mid-­‐2017
to
mid-­‐2019
will
bring
together
the
interna'onal
community
in
a
period
of
intensive
observing,
modeling,
predic'on,
verifica'on,
user-­‐engagement.
• This
is
an
opportunity
for
the
US
to
contribute
to
improved
polar
predic'on.
• Polar
predic'on
systems
lag
weather
predic'on
by
several
decades.