Ongoing research is documenting pronounced changes in the storage and transport of water in the Arctic’s atmosphere, rivers, lakes, ice and seas

The Arctic’s hydrologic cycle seems to be intensifying,most likely in response to global climate change

Climate Change in the Arctic and theIntensifying Hydrologic Cycle

http://zubov.atmos.uiuc.edu/ACIA/http://zubov.atmos.uiuc.edu/ARCTIC/

Our best climate models project that the Arctic will become warmer. And the Arctic is indeed warming

http://zubov.atmos.uiuc.edu/ACIA/

As well as wetter. And Arctic precipitation has indeed increased.

Courtesy Martin Visbeck, LDEOhttp://www.ldeo.columbia.edu/

The North Atlantic Oscillation

The North Atlantic Oscillation(NAO) (very similar to the Arctic Oscillation, or AO) is a big player in high latitude climate variability. Its “rise”From about 1970-1995 contributed strongly to winter/spring warming and changes in precipitation. Some evidence suggests that anthropogenic forcing may favor the “warm” positive mode of the NAO/AO.

Years

1935

1940

1945

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

Dis

char

ge a

nom

aly

(km

3/y)

-100

-50

0

50

100

150

200

Cum

ulat

ive

volu

me

anom

aly

(km

3)

-2000

-1000

0

1000

2000

3000

4000Average discharge anomaly for 5 year increments Cumulative volume anomaly from river inputs

*Anomalies are relative to average discharge from 1936 to 1955

Change in combined discharge from the 6 largest Eurasian arctic rivers

Yenisey, Ob', Lena, Kolyma, Severnaya Dvina, Pechora

http://ecosystems.mbl.edu/partners/

http://ecosystems.mbl.edu/partners/

Ocean Ocean trends on the . trends on the .

Ocean Ocean trends on the . trends on the .

Russia

Scandin

avia

1930 – 1965

N/AON/AO N/AON/AO

1965 – 1995

Russia

N/AON/AO N/AON/AO

Jet StreamJet StreamJetJetStreamStream

riverriverdischargedischargeisis lowerlower

riverriverdischargedischargeisis lowerlower

riverriverdischargedischargeisis higherhigher

riverriverdischargedischargeisis higherhigher

fresherfresher

saltiersaltier

Steele & Ermold, 2004http://psc.apl.washington.edu/

Shelves getShelves getsaltiersaltier

Shelves getShelves getfresherfresher

salinity trend (decade-1)

1.6

-1.6

0.4

-0.4

0

But why??But why??

Shelves getShelves getsaltiersaltier

Shelves getShelves getfresherfresher

Wind forces Wind forces fresh waterfresh waterrapidlyrapidly off-shelf off-shelf

Eastward windEastward windtraps freshwatertraps freshwater on the shelfon the shelf

trends in the .trends in the . trends in the .trends in the .

However! Working with the same data as H & P,

Nechaev et al. (2004) found a slight (~5%) fresheningfreshening trend, while

Swift et al. (2004) found a shift to higher salinitieshigher salinities in the 1970’s.

DataData: no obvious trends

ModelModel: trends are unreliable

adapted from Häkkinen & Proshutinsky, 2004

modelmodel(de-trended)(de-trended)

1950 1960 1970 1980 1990 2000

Sal

inity

ano

mal

y(in

ne

ga

tive

fre

shw

ate

r vo

lum

e,

10

3 km

3 )

-2

-4

0

2

4

datadatadatadata

Bottom line: The jury is still out.

http:/www.psc.apl.washington.edu/

Sept. 2002

Sept. 2004

Starting about 1960, the Arctic sea ice cover began to shrink, especially in summer and early autumn. The past three Septembers have seen extreme sea ice losses - 2002 probably had the least sea ice of the past 100 years.

http://www.nsidc.org/http://zubov.atmos.uiuc.edu/

Age and Thickness of Sea Icehas decreased.

Age: OW 0 1 2 3 4 5 6 8 10+

• Area of old ice has decreased dramatically during the last 15 years.• Recirculation of younger, thinner sea ice back to the Alaskan coast may

explain recent minima in summer sea ice extent.• These changes are related to the Arctic Oscillation.

OpenWater

OpenWater

Younger,thinner

Ice

Younger,thinner

Ice

Older,thicker

Ice

Older, thicker

Ice

September 2001September 1987

http://psc.apl.washington.edu/

The Greenland ice sheet now seems to be losing mass - as are many of the glaciers in the Arctic. This is contributing to sea level rise. In the summer of 2002, the area of the Greenland ice sheet undergoing surface melt was the greatest observed since 1979, when monitoring by satellites began.

Courtesy K. Steffen, NSIDC

http://cires.colorado.edu/steffen/

Permafrost

Permafrost – perenially frozen ground - covers much of the northern land area. In some areas of the Arctic, it may begreater than 1500 m in thickness. Permafrost seems to be warming and melting, with impacts on ecology, wildlife habitat and infrastructure.

http://www.nsidc.org/

http://www.uaf.edu/water/

Much of the Arctic is a desert, where freshwater is scarce and often frozen. The snowpack is critical to

residents who access subsistence resources in winter

http://www.uaf.edu/water/

In many areas of the Arctic, humans rely on snow and ice for drinking water.

http://www.uaf.edu/water/

Photo: Melinda Reynolds

Arctic residents rely on subsistence foods, such as these waterfowl. The birds depend on freshwater perched atop

continuous permafrost in summer.

Photo:Bill West AK/RO/00946

http://www.uaf.edu/water/

We must engage arctic residents as meaningful participants in the freshwater cycle, and the first to

face the impacts of a changing climate.

http://www.uaf.edu/water/