There are five primary factors that affect climate:
•Latitude (distance from the equator)
•Large Bodies of Water (oceans and large lakes)
•Air Circulation Patterns
•Altitude (elevation above sea level)
•Topography (features of the surface of land)
Latitude is one of the primary factors that affect the temperature of a region, and therefore the climate. The two primary factors that determine climate are precipitation and temperature. Solar insolation is a measure of the quantity of solar radiation received on the surface of the earth in a particular region or space at a particular time. Solar insolation is often measured in kilowatt-hours per square meter per day (kWh/m²/d). Latitude impacts solar insolation because as latitude increases the angle of incidence or the angle at which the sun’s rays strike the surface of the earth decreases. The planet is categorized into three climate zones according to latitude.
Tropical zone occurs between 23.5˚ south latitude and 23.5˚ north latitude forming a belt around the earth just above and below the equator. On the equator the angle of incidence is 90˚ as the sun is perpendicular to the surface of the earth. Therefore, the tropical zone remains warm year round with very little seasonal variation.
Temperate zone occurs between 23.5˚ and 66.5˚ north and south latitude forming two belts, one north of the equator and one south of the equator. In this zone the average angle of incidence is approximately 45˚. Although temperature remains relatively moderate in this zone there are definite seasonal variations between summer and winter.
Polar zone occurs from 66.5˚north to the North Pole and from 66.5˚south to the South Pole. In this zone the average angle of incidence is approximately 15˚.
Due to the tilt of the Earth’s axis the angle at which the sun’s rays hit the surface of the Earth changes as the Earth orbits the sun. The Northern hemisphere is tilted away from the sun during the winter thereby receiving less solar energy and tilted towards the sun during the summer months thereby receiving more solar energy. The Southern hemisphere is tilted toward the sun during the winter thereby receiving more solar energy and tilted away from the sun during the summer months thereby receiving less solar energy.
Altitude has an impact on climate as a result of the three distinct properties of air. Air cools as it rises and warms as it sinks. Areas at higher altitudes are colder than areas at lower altitudes. Warm air holds more water vapor than cold air. The air at high altitudes is normally very dry and there is little to no precipitation.
Topographical features such as mountain ranges can have an impact on climate by influencing how air masses travel and the amount of solar radiation that is absorbed or reflected. When an air mass encounters a mountain range, the air mass is forced to rise up and over the mountain range. As the air rises it cools and the water vapor in the air condenses into precipitation. By the time the air mass reaches the top of the mountain, most or all of the water vapor in the air has been lost to precipitation. Therefore the air that flows down the other side of the mountain is very dry and the “shadowed” side of the mountain receives very little or no precipitation. This phenomenon is called the Rain Shadow Effect.