Arctic

• What is the temperature in the Arctic Tundra?

  low all year, below 10
• Why is temperature so low in Arctic?

  located at a higher latitude, so receives less solar radiation
• When do temperatures increase?


  from February to July, likely due to increased daylight hours and Earth's axis pointing towards sun
• What is precipitation like in Arctic?

  low at 50-350mm/year
• Why is precipitation so low?

  limited evaporation due to limited solar radiation

  cold air holds less moisture
• When does precipitation increase slightly? Why?

  July- September due to increased temperatures allowing more evaporation
• Arctic Tundra Water Cycle ...
• Why is evaporation so low?


  most of sun's energy in summer is used melting snow and soil water is frozen in permafrost for most of the year
• Why is transpiration so low?

  little vegetation and short growing season
• In winter, how much solar radiation is reflected?

  85%- high albedo
• What influences albedo during summer season?

  vegetation type and its insolation capacity
• What happens in the frozen season?


  permafrost and lake ice increase land albedo:

  • reducing solar energy absorbed

  • providing insulation to reduce ground heat loss

  there is limited groundwater and soil moisture storage as permafrost acts as a barrier
• What happens in the thaw season?


  runoff is higher, carrying materials into Arctic Ocean through increase in river flow from groundwater flow, surface runoff, and throughflow
• How is bedrock of the tundra important?

  mostly Precambrian Igneous Rock, which is impermeable, so there's little percolation into aquifers
• Arctic Tundra Carbon Cycle... ...
• How long is the growing season?

  3 months
• What is NPP?


  50-350g/m2/year
• What happens in the growing season?


  leaf litter decomposes as there are more microorganisms active in the active layer, however waterlogged conditions starve them of oxygen
• What is the active layer?


  thawed surface layer of permafrost where plants can live for at least part of the year
• How is the permafrost a carbon sink and carbon source?


  carbon sink: contains 1600GT of carbon, full of dead organic matter

  carbon source: climate change is melting permafrost, releasing CO2 through decomposition in positive feedback
• How could thawing of permafrost be positive?


  it will allow enough water for plant growth as CO2 taken in by photosynthesis- however, this would only be 20% of CO2 released by melting permafrost
• Where is an example of the oil and gas industry affecting water and carbon cycles?

  Prudhoe Bay, Alaska
• When was gas and oil discovered at Prudhoe Bay?

  1968
• Where is Prudhoe Bay?


  North Slope of Alaska- between Brooks Range (south) and Arctic Ocean (north)
• When did extraction commence?


  1970/80s- investments in pipelines, roads, oil production plants
• By 1990 how much USA domestic oil was produced at Prudhoe bay?

  1/4
• How much is this today? Why?

  6%- high production costs and growth in oil shale industry in USA
• How many barrels of oil has the North Slope produced?

  18 billion
• How many barrels are estimated to be able to be produced?

  40-50 billion- production declined due to blockage by federal policies and environmental litigation
• How many jobs does the oil industry provide in Alaska?

  1/4 of all jobs
• How much of the economy does the oil industry in Alaska account for?

  1/2 of economy
• What is the most recent oil industry development in Alaska?

  Willow Project
• What does the Willow Project involve?

  a huge oil drilling project in the National Petroleum Reserve, owned by the federal government
• Which company is leading this?


  Conocophillips- a Houston-based energy company
• When was the plan approved? What changes have been made since?


  2020 by Trump administration- Biden has since reduced drilling pads from 5 to 3 as 3 will enable 90% of oil to be extracted
• Impacts on the water cycle...
• What does melting permafrost lead to?


  • increased runoff

  • increased peak flow

  • decreased lag times

  • more extensive wetlands

  • increased evaporation
• What has mining of sand and gravel for construction caused?


  it has created artificial lakes, which disrupt natural drainage of water and expose permafrost to further melting
• What has road construction led to?


  drainage networks being disrupted, increasing flood risk
• What has taking water from rivers for industry use led to?

  reduced local runoff