Climate

To review: Climate is… Weather is… Long-term behavior of atmosphere (100+ years) Large geographic area Very slow to change Weather is… Temporary behavior of atmosphere (what’s going on at any certain time) Small geographic area Can change rapidly

What Affects Climate? Latitude Topography Elevation Global Winds Ocean Currents Proximity to Water

Latitude Remember that latitude is the distance north or south of the equator. Where the sun’s rays are more concentrated, the temperature is higher.

http://www.wunderground.com/MAR/

Global Winds These are also determined by latitude. Thousands of kilometers long; can cause weather to move in different directions Jet stream, prevailing westerlies, doldrums, horse latitudes, trade winds

Global Winds Caused by the temperature difference in different regions Hot Tropical Regions—causes air to rise – results in more rain Cold polar Regions—causes air to sink - results in less rain

Global Winds Also affected by Earth’s Spin Coriolis Effect = causes winds to curve to the right in the N. Hemisphere; to the left in the S. Hemisphere

Topography Mountains force air masses up which reduces their temperature. As the temperature drops, condensation and precipitation occur. This creates a wet side and a dry side to the mountain range. It also creates strong downslope winds on the dry side of the mountain.

Hiking from the base of a high mountain at the Andes to its summit takes you through the same range of climate range of climate belts you would pass through on a hike from the equator to the pole.

Leeward Side (Wet) , Maui Hawaii

Windward Side (Dry) , Maui Hawaii

Elevation   Mountains receive more rainfall than low lying areas because the temperature on top of mountains is  lower than the temperature at sea level.  That is why you often see snow on the top of mountains all year round.  The higher the place is above sea level the colder it will be.  This happens because as altitude increases, air becomes thinner and is less able to absorb and retain heat.  

Proximity to large bodies of water The sea affects the climate of a place.  Coastal areas are cooler and wetter than inland areas. Clouds form when warm air from inland areas meets cool air from the sea.    The center of continents are subject to a large range of temperatures.  In the summer, temperatures can be very hot and dry as moisture from the sea evaporates before it reaches the center of the continent. 

Thus, the proximity of the sea tempers the climate of a region: as a rule, locations in the interior of a continent experience a much greater range of weather conditions than regions along the coast.

Ocean Currents Ocean currents affect the temperature of the land they pass by Cold ocean currents = cooling effect Warm ocean currents = warming effect Temperature changes affect pressure – which then creates WINDS Winds blow this cooling or warming effect over the land http://earth.rice.edu/MTPE/hydro/hydrosphere/topics/Ocean_Atm_Circ_ElNino.mov