Climate Geographic Literacy

Climate can only be described after you know something about weather…

Weather Defn: short term ( hours or days) conditions of the atmosphere. Conditions include: temperature (temp), precipitation (Ppt), wind etc.

Climate Defn: the collecitve day to day weather conditions over a period of many months/year. It is a result of the interaction of many different elements, with the most being temperature and Precipitation.

Climate patterns are a result of 3 general Geographic controls. Controls of Climate Climate patterns are a result of 3 general Geographic controls.

Controls of Climate 1) Latitude: depending on how far North or South you are located on the globe and what season it is. (the sun’s position/angle towards or away from the sun)

Controls of Climate 2) Continentality – based on the relationship between land and water. Land tends to heat and cool faster than water. Places far from large bodies of water experience greater seasonal extremes. (ex. Winnipeg!! Aka Winterpeg ;) Larger the land mass = greater the extremes Water generally acts as a moderating influence on climate

Controls of Climate 3) Topography: the relationship between altitude/elevation and temperature. The outcome is usually precipitation. ELR = Environmental Lapse Rate. – 6.4 degrees Celsius for every 1000m.

Orographic Precipitation Defn: rain or snow that falls when the air is cooled as it’s forced up because of a topographic barrier such as a mountain.

Orographic Ppt Windward side: direction from which the wind blows, the wind blows the warm air up, the rising air cools, the air condenses, clouds form causing Ppt on the windward (wet) side of the mountain. Leeward: opposite side of the barrier from which the wind blows down or away, the descending air(air that is coming down) warms and picks up moisture. Rainshadow: area on the leeward side of a mtn range where air flows down and is warmed and becomes drier. Ex. Chinook Winds in Calgary and Edmonton

Cyclonic or Frontal Ppt Where two different air masses flowing in two different directions meet. The warmer, lighter air will be forced to rise. The boundary is known as a *front. Precipitation will be light and will last for a long time.

Convectional Ppt On hot sunny days, in tropical areas and over large land masses. In the Northern Hemisphere, strong updrafts are put in motion. The sun heats the land surface, powerful vertical updrafts of warm air rise rapidly. This occurs on hot summer afternoons, forming towering Cumulonimbus Clouds. Ppt will be heavy and will last for a short period of time. The ppt is usually accompanied by thunder and lightening.