ELSS- Arctic CS Flashcards
Where is the Arctic located?
The Arctic is a polar region located at the northernmost part of Earth
How much does temperature range by in the Artic Tundra?
From -30C to 10C
What are the 3 influence on the water cycle?
-Temperature
-Geology
-Relief
How does temperature influence the water cycle in the Artic Tundra?
-Thawing of permafrost occurs in summer when temperatures are above 0°C increasing meltwater and reducing ice storage
-As permafrost melts evapotranspiration can occur and the biomass store can grow in summer
-Lots of water stored in cryosphere
How does Geology influence the water cycle in the Artic Tundra?
-Permafrost acts as an impermeable layer reducing infiltration or percolation
-Reduces the groundwater store in winter and increases overland flow
-In summer percolation occurs in soil moisture storage and flows increase
-Igneous rock formations have a dense crystalline structure that further reduces permeability
How does relief influence the water cycle in the Artic Tundra?
-A flat relief due to ice sheets create a thermokarst landscape
-Little GPE reduces surface runoff and increases infiltration creating a boggy landscape
-There is an increase in the surface store of water in alas lakes
What is the rate of processes in the Artic Tundra water cycle compared with the Amazon Rainforest?
Evapotranspiration = slower
infiltration = slower
percolation = slower
surface runoff = slower
Precipitation = slower
What are the sizes of water stores in the Artic Tundra compared with the Amazon Rainforest?
Atmosphere = smaller
biosphere = smaller
groundwater = smaller
cryosphere = larger
surface water store = larger
What biomes does Tundra lie between?
Ice and Snow, Needleleaf forest
How does precipitation change over the course of the year in the Artic Tundra?
It remains low - slightly higher in the summer months
Why is the tundra so cold?
-Because for 8-9 months there is a negative heat balance, due to its latitude
-Low insolation
What are the key stores of the water cycle in the Artic Tundra?
-Small stores of moisture in the atmosphere due to low temperatures that reduce absolute humidity
-Limited groundwater and soil moisture stores.
-Accumulation of snow and river/lake ice during winter months -Melting of active layer and snow in the summer results in sharp increase in river flow
-Extensive wetlands, ponds, and lakes on the Tundra surface during summer
What are the physical factors affecting the carbon cycle in the Artic Tundra?
-Biomass
-Temperature
-Geology
What are the key flows of the water cycle in the Artic Tundra?
-Low rates of evaporation: low temperatures and insolation mean ground is often frozen
-The permafrost is a barrier for infiltration, percolation, recharge, and groundwater flow
-Low annual precipitation (50-350mm)
-Limited transpiration because of the sparse vegetation cover (short growing season)
How does biomass influence the carbon cycle in the Artic Tundra?
-Lack of insolation reduces the biomass store
-Majority of carbon is stored as partly decomposed plant remains in permafrost
-Low photosynthesis and respiration.
-When decomposition occurs in waterlogged environments bacteria respire anaerobically releasing methane instead of usual CO2 aerobically
How does temperature influence the carbon cycle in the Artic Tundra?
-Rapid decomposition in summer months as bacteria rely on heat making decomposition a slower process and Photosynthesis, respiration and the tundra biomass store increase in summer as plants require sunlight
-Ocean gas exchange and soil storage of carbon increase in winter
What is the annual NPP for the Artic Tundra?
The average annual NPP is less than 200gcm2.
How does geology influence the carbon cycle in the Artic Tundra?
-Lack of soil nutrients (nitrogen) limits plant growth reducing biomass and evapotranspiration, respiration and photosynthesis
-Groupings of igneous rock around Baffin Bay with some sedimentary rock in the North
-Sedimentary rock is a larger store of carbon and due to rock being hidden away by the permafrost there is little metamorphism
-Less carbon released from the lithosphere to the atmosphere due to limited lithification, degassing or other processes in the slow carbon cycle
What are the key features of the biosphere in the Artic Tundra?
-Low growing perennial plants
-Few trees except for dwarf birch
-Ground level species dominate - mosses, lichen, heather, bilberry
-Low levels of biodiversity and biomass
-Slow growth rate
-Fragile - vulnerable to damage
What is permafrost?
Permanently frozen ground for 2 years in a row
How is carbon stored in permafrost?
It is frozen in the form of organic matter
What is the positive feedback loop in the Artic Tundra related to permafrost?
As the climate warms, more permafrost melts, and this means more greenhouse gasses are released. This then warms the climate more and the cycle repeats.
How may the artic tundra react to a warming climate in a negative feedback loop?
There will be more plants growing at the surface due to warmer conditions and these may absorb lots of the carbon released
What is a negative feedback loop?
Negative feedback loops return a system (the carbon cycle) back to a dynamic equilibrium after a shift away