TWO EXTREME ENVIRONMENTS

Hot, arid environments

  • hot deserts
  • semi-arid areas

Cold and high-altitude environments

  • polar areas
  • glacial areas
  • periglacial areas
  • high mountains in non-tropical latitudes
 
 

global distribution

 
 
Global Subregions (UN)

Global Subregions (UN)

DESCRIBING DISTRIBUTION

Distribution refers to the way something is spread out or arranged over a geographic area. 

Describe the distributions using the words below to help you. Check your answers by hovering over the images.

 

north/south/east/west                          named continents/regions                         coastal/inland                     highest/lowest                                         hemisphere                            tropics/mid latitude/polar    

In coastal areas. Highest in south west coast. Lowest north east coast and interior.

In coastal areas. Highest in south west coast. Lowest north east coast and interior.

Found in all regions of the world. Highest concentrations in northern hemisphere. Lowest in central Asia, northern North America.

Found in all regions of the world. Highest concentrations in northern hemisphere. Lowest in central Asia, northern North America.

Highest densities in south. Mainly extreme south and south west borders. Very low densities in north.

Highest densities in south. Mainly extreme south and south west borders. Very low densities in north.

 

EXPLAINING the GLOBAL DISTRIBUTION OF HOT, ARID ENVIRONMENTS

EXPLAINING GLOBAL DISTRIBUTION OF COLD AND HIGH ALTITUDE ENVIRONMENTS

Namib Desert. Namibia, South West Africa.

Namib Desert. Namibia, South West Africa.

Cold and high-altitude environments are generally found along constructive plate margins, where fold mountains form, or polar regions.

plate boundaries.png

Fold Mountains

Constructive plate margins

Mountainous regions have a high elevation, where atmospheric pressure is lower which causes lower temperatures.

elevation pressure.jpg

The sun's rays are received more easily, however, more solar radiation is reflected due to the high reflectivity of snow.

albedo snow.jpg

At higher latitudes less heat penetrates the atmosphere as it is thicker and spread across a greater area.

Latitude and solar radiation

Latitude and solar radiation

Hot, arid environments are found in the tropics. These areas receive direct sunlight in summer and winter.

Tropics and sunlight

Tropics and sunlight

Hadley cells in the atmosphere also cause aridity as the warm moist air rises from the equator.

This condenses and precipitates and the cooler air sinks over the tropical latitudes. The air is drier as cool air cannot hold as much moisture. The air then heats as it spreads over tropical regions and rises again.

Hadley cells and climate

Hadley cells and climate

Hot, arid climates can also be found in rain shadows, mountainous regions with arid areas behind them. The mountains cause relief rainfall and then the dry air blows across the landscape drying it out.

Rain shadow effect

Rain shadow effect

 
 

REVIEW

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