Climate and weather

The Effect of Water

• Bodies of water have a moderating effect on land temperatures
• Oceans and large lakes heat up and cool down more slowly than land masses
• In summer, a body of water remains cooler than the land surrounding it
• Winds blowing from over the water keep the surrounding countryside cooler than it would be if the water body was not present

The Effect of Water

• In winter, bodies of water retain their heat and are warmer than the land
• Winds blowing off the water body warm the surrounding countryside
• Therefore, maritime locations near a large body of water, have cooler summers and milder winters than continental locations

Ocean Currents

• Climate is affected by ocean currents
• The temperature of an ocean current affects the tempeature of air that passes over it
• On the West Coast, the warm North Pacific Furrent heats the cools, moist air which passes over it
• This gives a mild climate to the coastal regions of B.C.

Air Masses

• Air masses - a large volume of air with the climate conditions of the area where it is formed
• Air masses originating from oceans contain moisture. As the air passes over land, the moisture is released in the form of precipitation
• Therefore, maritime locations are more likely to receive more precipitation than inland
• On the other hand, air masses originating from a continental climate will be dry

Winds and Pressure Systems

• Air pressure - air that has weight
• Differences in air pressure are created when the earth is heated to different temperatures
• Warmed air rising above the heated ground creates an area of low pressure
• When the rising air has cooled, it falls toward the earth and creates an area of high pressure

Winds and Pressure Systems

• Heating of the ground by the sun warms the air above it and causes the air to rise. This produces a low-pressure area

2. The air cools and sinks. This produces a high-pressure area
3. Air at ground level moves from high pressure to low pressure, creating winds