ELSS - Arctic Tundra CS

Question 1

How much of the Northern Hemisphere does the permafrost cover?

Answer 1

1/4

Question 2

Why is there a huge accumulation of organic matter in soils in the Tundra?

Answer 2

When living organisms die, organic detritus does not decompose completely due to the cold temperatures

Question 3

What causes decomposition of organic matter?

Answer 3

Microorganisms and soil invertebrates

Question 4

How much carbon has been released into the atmosphere since 1850?

Answer 4

350 billion tonnes

Question 5

What gases does permafrost release?

Answer 5

CO2 and CH4

Question 6

What is the significance of the 10 degree July Isotherm?

Answer 6

When it stays below 10 degrees in the summer months

Question 7

What are the mean temperatures?

Answer 7

-15 degrees

Question 8

Which part of the ground is not permanently frozen during summer?

Answer 8

The active layer

Question 9

What temp can it get to in the winter?

Answer 9

-40 degrees

Question 10

What is annual precipitation?

Answer 10

<100mm

Question 11

Whats the most common form of precipitation?

Answer 11

Snow

Question 12

What is the length of the growing season?

Answer 12

3 months

Question 13

What happens in the summer in the Arctic Tundra?

Answer 13

• Vegetation store increases - increased evaporation, photosynthesis
• Permafrost thaws - release of greenhouse gases
• More moisture in the ground
• Ground heats up, convection

Question 14

What is the min discharge in winter in of th Yukon river?

Answer 14

340 cumecs

Question 15

What is the max discharge of the Yukon river in summer?

Answer 15

24,600 cumecs

Question 16

Why does permafrost store carbon?

Answer 16

Due to cold temperatures, organic matter cannot decompose
- Low temp means anaerobic bacteria less effective

Question 17

How much carbon stored in the ground?

Answer 17

5x more than above the ground

Question 18

How is the carbon store in the summer?

Answer 18

• Higher rates of decomposition due to thawing of permafrost, so increases in the atmosphere
• Higher veg density so increased photosynthesis - growing season

Question 19

How are carbon fluxes in the winter?

Answer 19

• Low veg density -> low photosynthesis, not enough sunlight
• Low decomposition rates
• Mainly stored in permafrost

Question 20

How is respiration in the summer and winter?

Answer 20

Summer:
- Increased veg, lots of moisture from permafrost melt -> higher

Winter:
- Colder temps, little moisture -> lower

Question 21

How much carbon does the permafrost store?

Answer 21

1,700 billion metric tons

Question 22

How much heat does methane trap compared to carbon?

Answer 22

30x

Question 23

What type of feedback is the thawing of the permafrost?

Answer 23

Positive feedback loop

Question 24

What are human factors influencing the water an carbon cycle?

Answer 24

• Spine Road
• Ice roads
• Oil extraction - TAPS, pipelines
• Gravel pads
• Removal of vegetation for oil extraction

Question 25

What are the effects of human factors to the Arctic Tundra?

Answer 25

• Reduction in surface albedo
• Direct thermal transfer
• Melting permafrost
• Deepening active layer
• Formation of talik
• Thermokarst lakes

Question 26

What do gravel pads generate?

Answer 26

Dust

Question 27

What are the physical factors affecting the water and carbon cycle in the Arctic Tundra?

Answer 27

• Temperature
• Relief
• Vegetation density
• Sunlight
• Porosity
• Soil

Question 28

What are the two types of permafrost?

Answer 28

Continuous and discontinuous