Energy Exchanges in the Atmosphere

Atmosphere - blanket of gas that surrounds the earth (the air around us)

Atmospheric Variables that cause weather conditions Temperature Pressure Air Movement Visibility Humidity

Weather - a description of the atmospheric variables at a given place during a short period of time

Where does most weather occur? In the TROPOSPHERE which is the LOWEST PART OF THE ATMOSPHERE

Atmospheric Variables

Temperature Variations affected by Insolation Altitude Clouds Pollution

Pressure Variations

What causes air Pressure? Gravity

Differences in Pressure are due to: Temperature Altitude Humidity

Temperature What is heavier warm air or cold air? COLD AIR

COLD AIR is more dense and wants to sink causing an increase in pressure

Altitude As altitude increases air pressure DECREASES

Because a smaller amount of air above you weighs less

Effect of Moisture Content or Humidity on Pressure

Opposite of what you normally expect

As the amount of Water Vapor in the air INCREASES, the weight of the air DECREASES

Because: water vapor molecules weigh less than dry air molecules

Measuring Air Pressure Air Pressure is measured using a BAROMETER

Atmospheric Pressure is measured in MILLIBARS and INCHES

Aneroid Barometer

ISOBAR- Line of equal air pressure.

Isobars are used ON WEATHER MAPS They help show us the location of HIGHS & LOWS

Air Movement

Wind - the horizontal movement of air

Atmospheric Transparency - a measure of the ability of the atmosphere to pass light

Dust, Smoke, Water Droplets, etc. in the air are called AEROSOLS / Condensation Nuclei

They directly affect Transparency which means, as the stuff in the air increases the amount of light that can pass through decreases.

Ingredients of Weather Ingredients of Weather 8min video