ARCTIC EXPLORATION

Problem Statement and Intro: Until recently, the scientific community knew relatively little about the Arctic Ocean. The difficulties in exploring this ocean are enormous - cold, ice, darkness. The military forces of the old USSR and of western nations, however, conducted a lot of secret research during the Cold War, and the data they collected was made public in 1997. This history-making release of data was described in the Feb 1997 National Geographic.

We will be exploring the Arctic Ocean using some of the information released onto the Internet in the last 2 years.

Use the Arctic Climatology Atlas Web Site to answer the following questions.

From the main table of contents, choose Introduction and Background.

You may read the articles (there is an especially useful diagram in one of them) on your own if you choose, but first go to the maps. Examine the maps.

1. Describe the floor of the Arctic Ocean.

2. Where is the Arctic connected to the other oceans? Are these connections shallow or deep water?

3. What nations border on the Arctic Ocean?

Return to the main table of contents then choose the link to Quick Time movies. The web site has some still pictures from the animations that are on the cd-rom. Our next stop is Arctic Ocean Bathymetry (depths).

4. How is this view different from the previous map?

5. What do you notice about the Arctic Ocean that you did not notice from the first maps?

Now choose the Arctic Ocean Climatic Temperature Fields; read the intro, then look at the stills.

6. Describe what happens to the warmer, saltier water from the Atlantic when it gets into the Arctic.

Go back and look at the Arctic Ocean Climatic Salinity Fields.

7. What happens to the large volume of fresh water that enters the arctic from Siberia and Canada? Does it mix immediately or does it form a layer? If it forms a layer, where is that layer?

8. What is the prevailing wind direction in the Arctic? How would this make the ice drift?

Now go back to the main table of contents and choose the Climatic Atlas, then choose the Temperature and Salinity Profiles and Transects.

A profile is a graph that shows data with depth in one location, and a transect shows data along a line. The two transects show temperatures along 2 lines.

9. Draw the transect lines on the following map.

10. How does the graph show the warmer water that came from the Atlantic? How did this warmer water get there?

11. Is there an underwater ridge that separates the main Arctic basin from the Atlantic, or are there channels for bottom water to pass through?

13. If pollution in the deep Arctic basin flowed with the bottom water, could it reach the Atlantic? Where?

Now go to the 90-270 transect

13. Is the warm Atlantic water there also?

Now we will try to figure out why the warm Atlantic water stays where it is. On the profiles chart, under 1980's temperature data, choose the Canadian Basin 2 link. Examine the graph carefully.

14. What does this graph show?

15. At what depth is the maximum temperature?

16. Speculate why this warmer water does not rise to the surface and melt the ice.

Now choose the Salinity profile for Canadian Basin 2 in the 1980's. And examine this graph carefully.

17. Look at the saltiness of the water from the surface down to the depth of the highest temperature (from question 16). Is this water fresher or saltier than the warmer water?

18. Where did this water come from?

19. Explain why the warmer water does not rise to the surface.

20. In the 1960's the Soviets proposed damming their main rivers to divert water south to irrigate crops. Describe what could have happened and why.

21. Read the article about thinning Arctic ice, then speculate about the effects if global warming causes the Atlantic warm water inversion to be buoyant enough to float to the surface of the Arctic.

The warm Atlantic water eventually cools off, sinks, and travels along the bottom back to the Atlantic (see the diagram in Water Circulation and Water Exchange in the Arctic Ocean and Contiguous Seas, in The Arctic Climate: A Russian Perspective in the introduction information, and the article in Encarta Online).

22. If something interfered with this movement so that the warm Atlantic currents no longer could go toward the Arctic, what would happen to the climate of Europe?

Arctic water that flows along the bottom of the Atlantic Ocean drives a circulation of water around the entire planet. Look at the diagram of this circulation from the article "Climate rides on ocean conveyor belt", then answer the following questions. Another article about possible changes to the deep water flow can be found at http://www.globalchange.org/sciall/99fall4.htm.

23. Describe the route that water takes as it travels around the world.

24. Speculate how changes in this flow could affect climate in other places of the world.

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