Weather and Climate

Is it the weather? The terms “weather” and “climate” are often used interchangeably. However, they are not the same. Weather is the state of the atmosphere at a specific time (e.g. current atmospheric conditions) Climate refers to long-term atmospheric trends. Climate is “average weather” measured on different time scales (usually 30 years) Both involve characteristics such as precipitation, temperature, atmospheric pressure, wind speed

Continental Maritime

Factors Affecting Climate Use the acronym: “LOWER Water” LATITUDE OCEAN CURRENTS WIND CURRENTS (air masses) ELEVATION RELIEF PROXIMITY TO WATER

LATITUDE As latitude increases (North or South from the Equator) the temperature decreases. This is due to a decrease in ‘concentrated’ solar radiation towards the poles.

Ocean Currents Ocean currents transfer heat (or cold) from one area to another. For example the Gulf Stream carries warm water from the Gulf of Mexico along the East coast of North America. The Labrador current carries cold water from the Arctic south towards Newfoundland.

Winds (Air Masses) Air masses carry heat and moisture across the landscape as they move from one area to another. m: maritime - coastal (high precip.) c: Continental –inland (low precip.) T: tropical - between the tropics (warm) P: Polar – originating at higher latitude than the circles (cool) Examples: mP: Maritime Polar cT: Continental Tropical

Elevation Temperature decreases with elevation. It is increasingly cooler at higher elevations in the troposphere (first layer of the atmosphere)

Relief Relief means the “lay of the land.” In Canada, south facing slopes are warmed more than North facing slopes because of more direct sunlight. Also, mountain ranges can block air masses and moisture from reaching certain areas, causes those locations to have dry climates.

Proximity to Water Water bodies have a moderating effect on climate. Because water has a high “specific heat capacity” it takes more energy to change the temperature of a water body than a an area of land. Therefore, areas close to bodies of water will have relatively mild winters and cool summers.

Climate Graphs Climate graphs measure temperature and precipitation for a given location (i.e. a city) over the course of one year. -temperature (y axis) -precipitation (y axis) -months(x axis)