Sea-ice atmosphere
What are polynyas important for and why?
It is important for animals and primary producers because it increases light permability and access to food.
How large is the Arctic ocean carbon sink?
a) 14 - 31 Tg C/year
b) -291 - 100 Tg C/year
c) 199 - 66 Tg C/year
What is the definition of permafrost and how much of the land in the northern hemisphere is permafrost?
Frozen soil for atleast two consecutive years.
25 % of the land is permafrost.
How does a Brinicle form?
Explain the solubility pump
A difference in partial pressure of gasses between the atmosphere and the water, causes gasses to be dissolved into the water.
Why is the decomposition rate low in the tundra?
Because it has low temperature and wet conditions
Why might gas hydrates be important and how much of worlds mobile carbon is stored in gas hydrates?
They might be important because the methane might be released to the atmosphere as carbon dioxide or methane, due to climate change. Gas hydrates contains about 1/3 of the worlds mobile carbon.
How does the biological pump work?
Primary producers use the carbon dioxide from the water. Zooplancton eats the primary producers. Primary producers and zooplancton dies and sinks to the benthic zone. It can either be buried in the ocean floor or remineralized by bacteria.
How can carbon mixed to deeper levels in the tundra?
Freeze-thaw process
At deep waters there are microorganisms which will anarobic and aerobic oxidation of the methane into carbon dioxide. Some of the released methane will become gas hydrates again, and some will be completely dissolved before it reaches the surface.
Why might the positive effects on the continental shelf pump caused by diminishing sea ice, level off?
Increased turbidity from rivers limits light permability and primary production. Hotter surface water causes stratification. Increased respiration with increasing water temperature
How does the climate change have an effect on the coastline?
Diminishing sea ice exposed the ocean to wind which causes waves. The waves will cause costal erosion.
Explain the sea-ice pump
When sea-ice forms, gasses, salt and nutrients accumulate in the brine and the heavy brine will sink and take the accumulated elements with it.
What causes winter and summer down welling of carbon at the continental shelf?
Winter down welling of carbon is caused by the cold surface water.
Summer down welling of carbon is caused by the biological pump
Why is there a discussion regarding respiration and photosynthesis in the tundra?
They are not sure whether the higher temperatures will stimulate increased photosynthesis or just increase respiration.