The Cryosphere

The Cryosphere

1. Earth's hydrosphere is permanently frozen

   • Arctic
     • Ocean covered by sea ice
     • Summer sea ice shrinks drastically
     • DEFINITIONS
       • Astronomical
         • 66N, 33"N
       • Temperature
         • Less than 10C (corresponds with treeline)
       • Characteristics
         • Aligned with Thermohaline Circulation (THC)
       • Vegetation
         • Forest - tundra transition
       • Political
     • Fragile
       • Temperature increase
       • Positive feedback (albedo)
       • Milankovitch Cycles
       • Sea ice climatology
   • Antartica
     • Continent covered in ice sheet
     • Ice shelves along coast
   • High mountains (1-2%)

2. Albedo + emissitivity

   • Snow has high albedo = high reflection of sunlight
   • + high emissitivity
   • Snow encourages negative energy balance
   • Night - surface emits well, day - reflects radiation

3. Conductivity + Insulation

   • Snow is a poor conductor, good insulator

4. Specific Heat Capacity

   • High = snow is slow to temperature change

5. Snow Density

   • WARM SNOW More moisture content
   • COLD SNOW Less dense

6. Glacier Formation

   • 1. Primary source is from snowfall. 2. Layers of snow build annually 3. Snow turns to ice as air pores are compressed and density increases. 4. Snow that survives 1 melt year is know as 'firn'. 5. Process is complete when interconnected air passages seal off - known as accumulation.

7. Avalanches

   • Caused by unstable snowpack
     • Weak under layer of snow
   • Weather
     • Wind
     • Precipitation
     • Increasing temperatures

8. Ice

   • Ice Density is lower than water
     • A. Ice floats on water. B. When water freezes it expands