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 the Intensifying Hydrologic Cycle
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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.
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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
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
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