🌍 elss sg4 Flashcards
location of arctic tundra
northern hemisphere
north of arctic circle at 66.5N
size of arctic tundra
8 million km squared
average annual temp of AT
-12.2 c
annual temp change
33c
average annual precipitation
137mm
type of seasons
summer: 2-3 months, 2-3c, always light
winter: 8-9 months, -30c, dark for 3 months straight
vegetation characteristics
no trees due to short growing season & low temps
some small shrubs in summer but very low NPP
soil characteristics
active layer: ground that is frozen in winter but melts in summer
permafrost: permanently frozen ground for at least 2 years
talik: unfrozen ground
precipitation in AT
very little and normally snow
evapotranspiration in AT
low temps so little ET as not enough heat to melt ice/snow
run off in AT
in summer more run off because ice melts, in winter stays frozen
infiltration in AT
permafrost is impermeable so water can’t infiltrate
store of water in atmosphere in AT
low temps so little ET
store of water in soil and ground water in AT
permafrost is impermeable so no water can infiltrate into ground (very small store)
store of water in vegetation in AT
not correct climate for vegetation to grow so very little water stored in it
store of water on surface in AT
in summer, impermeable permafrost so puddles etc
in winter none because active layer freezes
how does temperature in AT affect flows and stored in water cycle
very cold = low ET = so little stored in atmosphere
permafrost = impermeable surface = little stored in soil
how does rock permeability and porosity in AT affect flows and stored in water cycle
active layer becomes waterlogged as ground is impermeable so active layer becomes water logged and surface storage and overland flow increases
how does relief in AT affect flows and stored in water cycle
flat land due to weathering and erosion so lots of surface storage as doesn’t run off
photosynthesis in arctic tundra
short growing season as bad climate for vegetation to grow so little photosynthesis
respiration in arctic tundra
little respiration bc little vegetation and wildlife as too cold
decomposition and soil respiration in arctic tundra
too cold for decomposition so very little
ground is frozen so soil organisms can’t respire
carbon in the atmosphere in arctic tundra
small amount bc little respiration and decomposition
carbon in biomass in arctic tundra
small amount due to low temps, little water availability, few nutrients so vegetation doesn’t grow
carbon in permafrost in arctic tundra
large store bc when any vegetation does decompose, it stays frozen in soil for a long time
variations of daylight and temperature in the arctic tundra
winter: 0-12 hours of sun so no photosynthesis or respiration (carbon source)
summer: 12-24 hours of sun so permafrost melts and some carbon is released (carbon sink)
vegetation and soil organic matter in the arctic tundra
sparse vegetation due to short growing season so very little photosynthesis
not much soil respiration due to frozen ground
how does the oil and gas industry impact the water cycle in arctic tunda
causes ice to melt
- construction diffuses heat to ground which thaws permafrost
- removal of trees = less shade = more melting
- more concrete & dust lowers albedo
what is the impact of ice melting in the arctic tundra in water cycle
increase in surface storage = more surface run off = increase in river discharge = flood risk increase
increase in surface storage = more evaporation = more precipitation = flood risk increased
is the impact local, national or global on water cycle
local as only increases local flood risk
what is the trans alaskan pipeline (TAP)
800 mile pipeline through alaska to transport oil
what % of alaskan jobs does oil industry account for
25%
impact of oil and gas industry in alaska on carbon cycle
(positive feedback loop)
permafrost melts releasing carbon dioxide → more atmospheric co2
less photosynthesis as vegetation removed for construction → more atmospheric co2
more decomposition due to melting permafrost so vegetation can decompose → more atmospheric co2
is the impact on the carbon cycle local, national or global
global bc permafrost stores a lot of carbon so if it melts it would enhance global warming
what is a themokarst landscape
irregular surfaces of marshy hollows with methane in them
how do thermokarst landscapes spread
positive feedback loop
permafrost thaws creating waterlogged depressions (big puddles) → water retains heat for longer than surrounding ground → more melting → depth of active layer increases → more permafrost thawing
impact of darker surfaces and lower albedo
positive feedback loop
more road and airstrips built → bright surfaces are now darker → lower albedo → more of suns energy absorbed by ground → more ice melting creating darker areas of muddy peat bogs → bright surfaces now dark
impact on carbon cycle at global scale
positive feedback loop
more co2 in atmosphere → temp increases due to greenhouse effect → permafrost thaws → organic matter can now decompose → more co2 and methane in atmosphere
how does building infrastructure on gravel pads moderate carbon and water cycle
- insulates permafrost so less heat transfer to ground
- less melting of permafrost
- eg airstrip at Deadhorse
how does building infrastructure on stilts moderate carbon and water cycle
- cold air can still circulate between permafrost and building
- less melting of permafrost
- eg BP operation centre
how does building TAP on refrigerated stilts moderate carbon and water cycle
- insulated pipe to prevent heat loss from oil
- cold air can still circulate so permafrost doesn’t melt
- built on a track so can move which prevents leaks
how could the melting of the permafrost cause a tipping point
higher temps = sea ice melts → darker ocean is exposed → lower albedo → more solar radiation absorbed → ice melts
