40.3 Global Climate Patterns

40.3 Global Climate Patterns

  • Latitudinal variation in the inten is caused by the low angle of incoming sunlight.
    • More heat and light per unit of surface area are produced by the sun in the tropics because it strikes the north and south latitudes at the same time.
    • Light is more diffuse on Earth's surface when it strikes at an oblique angle at higher latitudes.
  • The global pattern of air circulation and precipitation is initiated by the intense solar radiation near the equator.
    • Warming in the tropics causes warm, wet air to rise and flow toward the poles.
  • The air goes toward the poles.
    • The air masses rise and fall at latitudes around 60 degrees north and south, but not as much as in the tropics.
  • The comparatively rainless and bitterly humid air is created when the air descends and flows back toward the equator.
  • Air flowing close to Earth's surface creates predictable wind patterns.
  • The more easterly and westerly flows are shown at the left.
  • The most significant influence on the distribution of organ in the middle to high latitudes is the long-term weather patterns around the sun.
    • The changing angle of the sun over the course of the year is an important component of the climate.
    • Local environments are affected by factors.
    • As the sun's angle changes, the belts of wet and dry air on either side of the equator can move northward and affect the distribution and abundance of organisms.
  • This is observed at the global, regional, and landscape levels.
  • Warming establishes the temperature variations, movements of air and water, and Ocean currents influence climate along the coasts of con evaporation of water that cause dramatic latitudinal variations by heating or cooling overlying air mass that pass in climate.
    • The coastal regions are formed differently than the rest of the country.
  • Earth is tilted on its axis relative to the sun and the intensity of solar radiation varies.
    • The variation is the smallest in the tropics.
  • The Northern Hemisphere tilts away from the sun and the Southern Hemisphere tilts toward the sun.
  • The sun faces the equator and neither pole tilts toward it.
  • The amount of surface water in the oceans around North America is affected by mountains.
    • California Current carries cold water along the western coast of North America because of the sunlight reaching an area.
  • South facing slopes in the Northern Hemisphere receive more sunlight than the cold California Current does and are therefore warmer and drier.
  • The distribution of species lo forest along the Pacific coast is influenced by physical differences.
    • The west coast of northern Europe and other conifers grow on the cooler north-facing slopes, which has a mild climate because the Gulf Stream carries warm water.
    • The slopes are north facing.
    • In addition, every 1,000-m elevation increase in western Europe is warmer in the winter than in the southeastern part of the country, which leads to an average temperature drop of 6degC, equivalent to Canada, which is farther south but is cooled by the Labrador.
  • The current is flowing south from the coast.
  • Because of the high specific heat of water, it can be similar to lower- elevation communities that oceans and large lakes tend to moderate the climate of nearby.
  • We turn now to the role of climate in determining the nature peratures drop more quickly over land than over water at night, and location of Earth', major life zones character air over the now warmer water rises, drawing cooler air from ized by vegetation type.
  • The figure shows how large bodies of water and mountains affect the climate.
  • The figure shows how water can be released as rain and snow.
  • Cool air moves inland from the water.
  • The Leeward side has little precipitation from the mountains.
    • On the back side of the mountain range, the rain shadow can create a desert.
  • Latitudinal patterns of the climate are described in Figure 40.3 and also in Figure 40.7.
  • Other areas may have distinct wet and dry seasons, while annual mean precipitation may receive regular precipitation throughout the year.
  • The Figure 40.8 A climograph for some major types of biomes in North America is altered by natural and human-caused disturbances.
    • The areas plotted here have the distribution of biomes in them.
    • A range of annual mean temperature and precipitation is a disturbance.
  • Major physical or cli disturbances have altered much of Earth's surface, replacing matic features with vegetation.