geog 2136 tundra

What area is expected to be an indicator of global climate/environmental change?

Arctic ecosystems

What makes the arctic sensitive?

Large seasonal fluctuations in solar radiation, high albedo, zero degrees (permafrost, sea ice, vegetation, snow cover)

Positive Feedbacks to Global Climate in Arctic

Temp increases→snow cover decreases→albedo decreases, which makes temp increase even more

Temperature increases→permafrost melts and releases trace gases/carbon, which makes temp increase even more

2 big feedbacks in Arctic

Snow albedo temp, and permafrost trace gas

Third feedback in Arctic

thermohaline circulation

what is thermohaline circulation

the ocean moving heat, salt, and nutrients globally by changing water density with temperature (thermo) and salinity (haline)

what are changes in thermohaline circulation caused by?

increased run off

what do changes in thermohaline circulation lead to?

changes in arctic ocean salinity

changes in ocean circulation

sea ice

weather patterns (arctic oscillation)

how do you define the arctic?

very little precipitation, temperature is very cold. could have 0 daylight hours or nearly 24 daylight hours depending on the season. very extreme

what changes are being predicted in the arctic

via GCM’s: Most models show increased precipitation and soil moisture, spatially variable, and complete loss of the arctic ice caps by 2050.

what is the uncertainty with GCM predicted models in the arctic?

accuracy, spatial resolution, and processes

observations of climate change in the arctic

vegetation changes. can be caused by temperature, nutrient availability, depth of active layer, and precipitation

what is the influence of vegetation changes in the arctic

Permafrost trace gas feedback, Snow albedo feedback, Energy balance

observations of climate change with ITEX

International tundra experiment — adds cones which increase temperature to see how it affects tundra vegetation