Heating of Land and Water

Land Heats up faster and Cools down faster than water

Winds•Movement of air from an area of high pressure to an area of low pressure.•Winds are caused by differences in air pressure.•Differences in air pressure are caused by the unequal heating of the Earth.

• Wind-chill factor- Measure of cooling. It combines temperature with wind speed.

• The name of the wind tells you where the wind is coming from. (South wind blows from the South)

Local Winds

• Sea Breeze- blows from ocean or lake

• Land Breeze- blows from land to a body of water.

Global Winds• Global Convection Currents- Differences in air

pressure causes winds to blow from the poles toward the equator.

Coriolis EffectEarth’s rotation makes winds curve to the right

(clockwise) in the Northern hemisphere and to the left in the southern hemisphere (counter clockwise).

Air masses

• Air Mass- body of air that has similar temperature, humidity, and air pressure.

• Polar- cold• Tropical- warm• Maritime- form over oceans, humid• Continental- form over land, dry

Air Masses

• Maritime Tropical- over ocean, humid, warm

• Maritime Polar- over ocean, humid, cold

• Continental Tropical- over land, dry, warm

• Continental Polar- over land, dry, cold

In the US air masses are commonly moved by winds. They move from west to east.

Fronts

Colliding air masses can form four types of fronts: cold fronts, warm fronts, Stationary fronts and

occluded fronts

All Fronts have the following in common:

• The warm air rises.

• The cold air sinks.

• When the cold and warm air touch condensation will happen and clouds will form.

• Clouds result in precipitation.

Cold FrontFast moving cold air mass overtakes a warm

air mass. Results in clouds, precipitation and thunderstorms. After- clear skies and

lower temperatures.

Warm Front

Fast moving warm air mass overtakes a cold air mass. Results in clouds and precipitation. After-

warm and humid

Stationary Front

Cold and warm air masses meet but neither moves. Results in clouds and precipitation.

Occluded Front

Warm air mass is caught between two cold air masses. Results in cooler temperatures clouds

and precipitation.

Symbols

Isolines

Lines on maps that connect equal measurements at a given time.

There are three types:

a) Isobar- equal atmospheric pressure. (mb)

b) Contour lines- equal altitude. (m)

c) Isotherm- equal temperature. (Celsius or Farenheit)

Wind Speed

Measured with an anemometer

Station Models

Weather Maps

• High Pressure- Clear Weather

• Low Pressure- Stormy weather

Storms

A storm is a violent disturbance in the atmosphere.

Thunderstorms- thunder and lightening

Avoid places where lightning may strike, and objects that conduct electricity.

Tornado

Fast whirling funnel shaped cloud that reaches down from a storm cloud to touch the ground .

The safest place- basement

Hurricane

Begins over warm ocean water as a low pressure area or tropical disturbance.

If asked to evacuate leave the area.