Climate Factors

• Weather


  Events that take place over the course of a few hours to a few days
• Climate


  The overall weather for a particular area over a given period, taking into consideration the averages of weather data collected over time
• Climatologists use averages to calculate climate, such as average annual temperature
• The average annual temperature may be the same for two different places on Earth, but that does not mean their climate is the same
• Daily temperature range


  The difference between the highest and the lowest temperatures for the day
• Annual temperature range


  The difference between the warmest month and the coldest month
• India has two seasons: the wet season and the dry season
• Climate controls


  • Latitude
  • Prevailing winds
  • Topography
  • Altitude
  • Distances from oceans and lakes
  • Ocean currents
  • Vegetation
  • Cloud cover
• Latitude


  An imaginary line that runs from east to west beginning with the Equator at 0°
• Equatorial region (5-10° N/S of Equator)

  • 12 hours of daylight and 12 hours of darkness year-round
  • Temperatures are hot, especially at sea level
  • No distinction in seasons
  • Only dry and rainy seasons
  • Temperatures do not vary much
• Mid-latitudes (around 40° N/S)


  • 15-16 hours of sunlight in July in Northern Hemisphere and January in Southern Hemisphere
  • Temperature varies as much as 30°C
  • Average temperature is lower because Sun is not directly overhead
• Polar regions (above Arctic Circle and below Antarctic Circle)

  • 6 months of daylight and 6 months of darkness
  • Very little heat from the Sun during 6 months of darkness
  • Temperatures are very cold and do not change much
  • Temperature fluctuation during the day is almost nonexistent
• Altitude


  The height above sea level
• Effect of altitude on temperature

  • For every 160 m in height, the temperature drops 1°C
  • Average annual temperature is much colder the higher up you go compared to sea level at that latitude
• Effect of mountains on temperature and precipitation

  • Wind blows against the windward side, preventing it from reaching the leeward side
  • Windward side receives more rainfall, leeward side is drier
• Climate Factors


  • Temperature
  • Latitude
  • Altitude
  • Ocean currents
  • Wind currents
  • Rainfall and latitude
  • Oceans and landmasses
• Ocean currents affect climate

  1. Warm currents like the Gulf Stream heat up the air above the water

  2. Warm air is blown to coastal land areas, warming them

  3. Warm air is carried by the Prevailing Westerlies to Scandinavia and the UK
• Wind currents affect climate

  1. Prevailing Westerlies blow from west to east, carrying marine, tropical moist air masses

  2. Air masses blown over mountain ranges create different climates on each side
• Continental climate


  Experienced on East Coasts of continents in mid-latitudes, with hot summers and cold winters
• Marine/maritime/oceanic climate


  Experienced in coastal areas in mid-latitudes, with smaller annual temperature range due to ocean influence
• Examples of continental vs marine climates

  • Great Plains (continental)
  • California coast (marine)
• Rainfall and latitude


  1. High rainfall at Equator due to rising warm air in ITCZ (Intertropical Convergence Zone)

  2. Rainfall decreases away from ITCZ as air diverges

  3. Sinking air creates dry regions like deserts 20-35 degrees from Equator

  4. Low pressure areas 30-65 degrees from Equator cause precipitation
• Polar Easterlies are high pressure areas near the poles where cold air sinks and diverges
• The __________ is a very warm current that comes up from the Gulf of Mexico along the East Coast of the United States

  Gulf Stream