Weather and Climate
A description of weather usually mentions temperature, moisture or precipitation.
Atmosphere- a multilayered band of gases, water vapor, and dust above the earth.
Green house effect- is the trapping of the suns solar radiation inside the earth’s atmosphere.
Weather and climate are related but not synonymous.
Rotation and Revolution
Rotation- 24 hours -the earth is tilted at 23 ½ on its axis
Revolution- one revolution occurs every 365 ¼ days
- to account for the ¼ , every four years we make the year 366 days
(Leap Year), we add a day in February to make 29 days
Seasons
The earth’s tilt means that the sunlight strikes different parts of the planet more directly. This causes the season to change.
Solstices- when the sun appears directly overhead at the
Tropics of Capricorn and Cancer
-summer (June 21) when the Northern Hemisphere is tilted closer to the sun
-winter (December 21) Southern Hemisphere is tiled closer to the sun
Equinoxes- the sun, at noon, appears directly overhead at the Equator.
- spring (March 21)
- fall (September 23)
- on these dates the lengths of day and night is nearly equal everywhere on earth
Latitude and Climate
Geographers use latitude, or distance from the Equator to divide the world into zones.
Ø Tropical zones (low latitudes)-are measured from 23 ½ degrees north and south latitude
Ø Temperate zones (middle latitudes)-are measured from
23 ½ - 66 ½ degrees north and south latitude
Ø Polar zones (high latitudes)-are measured from 66 ½ degrees North and south latitude to the poles.
Distributing the Sun’s Heat
Convection- the transfer of heat from one place to another
- warm gases and liquids rise
- cooler gases and liquids sink
Distributed 2 different ways- (wind and water)
- warm from the equator to the poles
- cold from the poles to the equator
1. Wind
-Rising warm air creates areas of low pressure
-Falling cool air causes areas of high pressure
Coriolis effect- is the deflection of the winds from the equator and the poles.
Doldrums- the area near the equator which has light winds
Horse latitudes- 30 North and South latitude, calm
Trade winds- blow toward the equator, between the doldrums and horse latitudes
2. Water (Currents)
-currents carry warm water from the equator to the poles
-wind and Coriolis effect influence the circular patterns of currents in the oceans