1. 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

2. 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

3. http://zubov.atmos.uiuc.edu/ACIA/ As well as wetter. And Arctic precipitation has indeed increased.

4. Courtesy Martin Visbeck, LDEO http://www.ldeo.columbia.edu/ 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.

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

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

7. Ocean trends on the. Russia Scandinavia 1930 – 1965 N/AON/AO 1965 – 1995 RussiaN/AON/AO Jet Stream JetStream riverdischarge is lower riverdischarge riverdischarge is higher riverdischarge fresher saltier Steele & Ermold, 2004 http://psc.apl. washington.edu/ Shelves get saltier fresher salinity trend (decade -1 ) 1.6 -1.6 0.4 -0.4 0 But why?? Shelves get saltier fresher Wind forces fresh water rapidly off-shelf Eastward wind traps freshwater on the shelf

8. trends in the. trends in the. However! Working with the same data as H & P, freshening  Nechaev et al. (2004) found a slight (~5%) freshening trend, while higher salinities  Swift et al. (2004) found a shift to higher salinities in the 1970’s. Data  Data: no obvious trends Model  Model: trends are unreliable adapted from Häkkinen & Proshutinsky, 2004 model(de-trended) 1950 19601970 19801990 2000 Salinity anomaly (in negative freshwater volume, 10 3 km 3 ) -2 -4 0 2 4 datadata Bottom line: The jury is still out. http:/www.psc. apl.washington.edu/

9. 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/

10. Age and Thickness of Sea Ice has decreased. Age:OW 01234568 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. Open Water Open Water Younger, thinner Ice Younger, thinner Ice Older, thicker Ice Older, thicker Ice September 2001September 1987 http://psc.apl. washington.edu/

11. 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/

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

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

14. 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/

15. In many areas of the Arctic, humans rely on snow and ice for drinking water. http://www.uaf.edu/water/ Photo: Melinda Reynolds

16. 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/

17. 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/