1. Polar Landscapes

2. A Regional Approach
All elements of physical geography integrated in the ecoregion approach of Robert Bailey, UCLA Geographer, U.S. Forest Service

3. For GCU 672
Organized by basic climate processes controlling precipitation and temperature
Intertropical Convergence Zone (ITCZ) – brings summer rains in equatorial &
tropical latitudes
Subtropical High – brings drought, annually or seasonally
Polar Front – brings precipitation in the midlatitudes
Polar Easterlies – the cold landscapes of tundra and ice caps

4. Organization 1st – climate 2nd – soils 3rd – landforms & hydrology
4th – biogeography
with discussion of geology because geology plays an important role in deserts in defining meso-scale landform regions

5. Polar Climates

6. Dominated by Polar High
Dense, cold air flows equatorward

7. Extreme Seasonal Changes
24 days in summer, 24 night in winter

8. Ice Cap Climate
Mean monthly
below zero

9. Ice Cap Climate Dominated by dry, frigid air masses
Average temperature below freezing most or all year
World’s coldest surface air is found in Antarctica in S. hemisphere winter
Glaciers accumulate snow and ice despite low precipitation (<80mm/yr in Antarctica)
Precipitation exceeds small evapotranspiration demand
Examples: Antarctica, North Pole, Greenland

10. Classroom Resource Folder
Online Video Resource
Address
Movie of
Movement Of
Arctic
Sea
Ice
Classroom Resource Folder

11. Tundra Climate harsh winters low average temperatures
little snow or rainfall
too short summer season for trees.
Influenced by permafrost, a layer of permanently frozen subsoil in the ground. The surface soil, which tends to be rocky, thaws in summer to varying depths.
The combination of frozen ground and flat terrain impedes drainage of water. Held at the surface or soaking the upper layer of soil, the water forms ponds and bogs in low areas

12. Classroom Resources
Alaska Animations – focus on Arctic tundra where get extremes of temperature & little precipitation

13. Soils
Poorly Developed
In Rocky Areas

14. Soils
Experience overturning from permafrost activity

15. Soils: Position is very important
Lowland soils: histosols
Peat – plant accumulation
Upland soils: entisols
Poorly developed

16. In low-lying areas where water collects from permafrost melting, get accumulation of organic remains of plants called PEAT.
Name for soils: histosol

17. Why does peat accumulate ?
Production by plants exceeds decomposition
Abundant growth due to available moisture during growing season
Preservation of plants (cool conditions)
Saturated conditions - slow, anaerobic decomposition by methanogenic bacteria
When plants decay (with drying & warming), release of methane

18. Landforms & Hydrology Permafrost Ice Wedge Polygons Pingo
Patterned Ground
Solifluction
Rocky Uplands
Rivers

19. Permafrost
Permanently frozen water in the ground

20. Underground mine in permafrost (Yakutsk, Permafrost Institute, Dr. P
Underground mine in permafrost (Yakutsk, Permafrost Institute, Dr. P. Konstantinov

21. When thaws, creates “thermokarst”
Pipelines Break
Roads Cave In

22. Buildings Collapse if not properly insulated

23. Natural permafrost cycle

28. Northwest Territories

29. Northwest Territories

30. Pingo
Northwest Territories

31. Pingo

33. Can grow as water moves to ice core

34. Patterned Ground – Rocky & Flat
active layer “churning” sorts rocks

35. Northwest Territories

36. Solifluction: sloped ground in finer materials flows (oozes)

37. Kinnard Research, Excavation, Yukon

38. Topographic Position Rocky uplands patterned ground Low slopes
solifluction lobes
Lowlands
ice wedge polygons

39. Rocky Uplands
Felsenmeer – rock block field broken up by frost weathering

40. Steep slopes with lots of frost-weathered rock: Rock Glaciers
Ice core & seasonal freeze/thaw moves rocks

41. Rivers
Winter – frozen
Spring – thaw
Summer – very
aggressive
erosion

42. Breakup Timing

43. River Ice
River ice is a unique aspect of Arctic Hydrology. All rivers experience some ice effect, yet in some instances, runoff events associated with river ice have produced extreme and dangerous flooding events. River Ice interacts and obstructs the passing of floods. The blockage causes water levels far higher than those experienced for the same flows under open water conditions.

44. YUKON RIV HARD LIFTED AND SHIFTED SHEETS
Shifted ice – large ice sheets that have moved short distances from their original locations as rising water levels create wider areas of open water into which the ice can move

45. Reach of large moving sheets (nr breakup front)
TYPICAL RUN OF ICE
May be miles in length
Reach of large moving sheets (nr breakup front)
Reach of mixed sheets, pans, and chunks
Reach of mostly chunks
Subsequent runs are mainly chunks

46. YUKON RIVER Ice run – a continuous length of moving ice

47. NULATO RIVER ICE JAM
Ice jam – an ice run that has stopped moving due to any of a variety of reasons; this very small jam has broken sheet ice holding back a small run of chunk ice

48. ICE JAM IMPACTS Upstream from the jam...
Fast water level rise
Packed ice chunks
Potential flooding

49. Flooding impact Water outside the channel

50. KUSKO RIV ANI VILLAGE FLOODING
Village flood – water spreading into a village that covers roads or threatens buildings

51. Lena River Delta
Yukon R. Delta

52. Biogeography

53. Cold & Dry

54. Effect of Latitude
or Altitude
Source: Solomon, 2000

55. Tundra -severe winters -short growing season, cool summer; too little
warmth for tree growth
-arctic or alpine

56. Small growing season Generates dwarf forms adapted to survive in
Cold and Windy winters
Dwarf Willow
Dwarf Birch

57. Long, bitter-cold winters characterize the tundra
The arctic tundra lies between the Boreal Forest and the permanently frozen polar regions
It is a treeless biome characterized by extreme cold, wind, and permafrost
Permafrost is continuously frozen subsoil

58. SNOW AND MICROCLIMATE
The snow on top helps protect the tundra plants underneath from the worst of the cold above. When it is very cold outside, take a thermometer and measure the temperature underneath the snow, and you will see that it is quite a bit warmer! This helps not only the tundra, but small rodents such as the red-backed vole.

59. Arctic tundra
Light and heat may not be the only limiting factors for plant growth
Days are long and temperatures may reach the teens in summer
Wind and moisture deficit are also important
Thin, active layer holds limited moisture. Small, leathery leaves, closely spaced to protect stomata
Hairs limit air circulation
Flowers are small
Plants often occur in tufts for protection
Prostrate growth - stems spread out over ground with little vertical growth - especially willow

60. Lichens Common Food for Caribou
Mutualism: Relationships between fungi and hosts that are mutually beneficial
Fungal layer
Algal layer
Symbiosis: intimate association between two distantly, related species that are mutually benefiting from this association
Fungal layer

61. Adaptations to Light Conditions -Perennials
These plants come back every year. Short flowering & reproductive season
Tundra Flowers

62. Low Arctic Tundra
Extends north from treeline along a line from Northern Alaska to northern Quebec and southern Baffin Island (10 degree C isotherm)
Cold, with low precipitation
Nearly the entire area is underlain with permafrost
Almost complete vegetation coverage (except unfavourable areas)
Dominated by dwarf shrubs (birch and willow)
Vegetation traps snow and provides shading from summer heating
Peat accumulation at poorly-drained sites
Any black spruce is very stunted and abraded by snow
Major summer range and calving grounds of some of Canada's largest caribou herds

63. Mid Arctic Tundra Transitional band between high and low arctic
Plant cover more than 50% in most areas but bare ground still exists locally
Vascular plants more common than in high arctic - willow common
Cumberland Sound, Baffin Island, Nunavut, Canada

64. Wetland Environments
Cover 14 to 18% of Canada
Mainly just to the south of treeline in discontinuous and sporadic permafrost
Pockets further north
Major carbon sink
Potential future source of greenhouse gases (methane)
Hydrophyllic vegetation present due to water table at or above mineral soil

65. Example of Plants Willow-herb Sedge
Cotton grass has seeds that are dispersed across the tundra by the wind.

66. Source: Natural Resources Canada

67. Online Video Resource
Address
Ecogeeks

68. Animals of the Tundra – Color Adaptations
These animals turn white in order to camouflage themselves from predator or prey
Lemming
Arctic Hare
Arctic Fox

69. Animals of the Tundra – Cold Adaptations
Arctic ground squirrels hibernate
Polar bears shelter in dens in winter and to have cubs

70. Animals of the Tundra
Caribou migrate south during winter in search of food
Muskox dig through snow in winter for food, if snow is frozen solid, they could die

71. Birds of the Tundra Snow geese migrating north in summer
Tundra birds help to distribute seeds. When they eat bright colored berries, they fly to other areas and leave the seeds to grow.

72. Food Sources The Arctic Fox eats birds and rodents.
                               
The Arctic Fox eats birds and rodents.
The Musk ox eat lichen, moss, grass, and leaves.
Food Sources
Lemming eats grass & other vegetation.
The Polar bear eats large & small mammals, birds, fish, berries, and leaves.
Caribou eat lichen.

73. Online Video Resource
Address

74. Classroom Resource
World Wildlife Fund – Polar Bear Status

75. Arctic Warming at the Front Line of Global Change
Hansen, Scientific American, March 2004

78. Dramatic changes in Artic Sea Ice
: Progressive Loss of Arctic Ice
Imagine an ice-free Arctic
In September 2003, scientists from the United States and Canada announced that the largest ice shelf in the Arctic had broken up. The Ward Hunt ice shelf to the north of Canada’s Ellesmere Island split into two main parts, with other large blocks of ice also pulling away from the main sections. Evidence continues to emerge that average temperatures in the Arctic are rising even more rapidly than the global average. Satellite data indicate that the rate of surface temperature increase over the last 20 years was eight times the global average over the last 100 years. Studies report that the extent of Arctic sea ice has shrunk by 7.4 per cent over the past 25 years, with record-low coverage in September An analysis of 30 years of satellite data suggests that the loss of Arctic sea ice is also accelerating. There are projections that much of the sea ice, until now thought to be permanent, will melt during the summer by the end of this century if the current trend in global warming continues. This will have major direct impacts on indigenous people and Arctic wildlife such as polar bears and seals, and will also open the region to increased development pressure as access by sea to valuable natural resources becomes easier. The global impacts may also be significant as absorption of solar radiation increases, and could lead to changes in the world ocean circulation.

79. Source:
Corell, R. W., 2004: Impacts of a warming Arctic. Arctic Climate Impact Assessment ( Cambridge University Press (

80. Classroom Resource
NOAA Prediction of Arctic Sea Ice

81. The increase in growing season length over the last 50 years averaged for eight stations in Alaska having the longest and most consistent temperature records.
Gradual Loss of Tundra (purple) as growing season lengthens
The increase in growing season length over the last 50 years averaged for eight stations in Alaska having the longest and most consistent temperature records.

82. Classroom Resource Some models show loss of Tundra (purple) from
Lawrence
Livermore
Laboratory

83. Imagery seen in this presentation is courtesy of Ron Dorn and other ASU colleagues, students and colleagues in other academic departments such as Profs. Oberlander at U.C. Berkeley, individual illustrations in scholarly journals such as Science and Nature, scholarly societies such as the Association of American Geographers, city, state governments, other countries government websites such as Canada and U.S. government agencies such as Dr. Robert Bailey and the U.S. Forest Service, NASA, USGS, NRCS, Library of Congress, U.S. Fish and Wildlife Service USAID and NOAA.