Presentation on theme: "General conditions of temp & precipitation for an area over a long period of time. Southwest US – hot, dry all year."— Presentation transcript:
General conditions of temp & precipitation for an area over a long period of time. Southwest US – hot, dry all year.
Climate of a region is determined by: 1. Temperature 2. Precipitation
FACTORS THAT AFFECT TEMP 1.Latitude- measure of the distance N & S of equator. Closer to equator, more direct sunlight, warmer climate. Farther away from equator, less sunlight, cooler climate.
2. Elevation- as elevation increases, air cools & cant hold as much moisture so temp decreases.
3. Ocean Currents - a river of water that flows in a definite path in the ocean. The surface temp of water affects the temp of the air.
Warm water currents travel away from equator. Cold water currents travel toward the equator. Land near currents is affected by the temp of the ocean currents.
4. Distances From Water Oceans greatly moderate the temps of nearby land. Water heats/cools slower than land.
FACTORS THAT AFFECT PRECIPITATION 1.Prevailing Winds - Carries different amounts of moisture which affects precipitation.
Winds that blow from sea to land carry more moisture. Places in the center of a land mass have dry climates.
Region that receives less than 25cm of precipitation in one year.
2. MOUNTAIN RANGES Act as barriers to winds Mountains cause air to rise 2 parts of a mountain: windward side & leeward side
A) Windward side- receives a lot of precipitation. Faces the wind. B) Leeward side- drier air. Faces away from wind.
How Mtns. Affect Precip. Air is forced up. As it rises, it starts to cool. Cold air cant hold as much moisture so precipitation occurs on the windward side. Air that comes over the Mtn. (leeward side) is drier.
3. SEASONAL WINDS Monsoon- a major landbreeze or seabreeze that changes direction with the seasons.
THE SEASONS Most places outside the tropics have 4 seasons: summer, fall, winter, & spring.
Causes of Seasons Tilted Axis- the tilt of the earths axis as the earth travels around the sun. Tilted on an angle of 23.5
The north end of the axis is pointed away from the sun for part of the year (Winter)& toward the sun for another part of the year (Summer).
In summer, N. hemisphere is tilted towards the sun = more direct sunlight, warmer temps. (June) In the winter, N. Hemisphere is pointed away from sun = less sunlight, colder temps. (December)
CLASSIFICATION Climates are classified according to: 1. Temperature 2. Precipitation
6 Main Climate Regions 1.Tropical rainy 2.Dry 3.Temperate marine 4.Temperate continental 5.Polar 6.Highlands
Found in low-lying lands near equator. 2 types: Tropical Wet, & Tropical Wet-&-Dry.
Hot/Humid, many rainy days, over 10meters/year. Windward side of Hawaii Rain Forest- forests in which large amounts of rain fall year- round.
Hot, receives slightly less rain & has a distinct dry & rainy season. Savannas- tropical grassland Southern Florida
A climate is dry if the amount of precipitation that falls is less than the amount that evaporates. Arid Climate & Semiarid Climate.
Desert, with little precipitation (less than 25cm/year). Hot, sandy & cold or rocky Parts of California & Southwest.
Dry but receives 25-50cm of precipitation/year. Steppe- dry region that gets enough rainfall for short grasses & bushes to grow. Great Plains
Along the coasts of temperate continents Humid (50F+) in summer & mild winters (20F to 64F). Mediterranean, Humid Subtropical, Marine West Coast.
Coastal climate that is drier & warmer than West Coast Marine. Mild winters, cool summers, & moderate rainfall. (agriculture) Southern California,
Warm, dry summers & rainy winters Northern California to Southern Alaska Because of heavy precipitation, thick forests grow here.