Warm-up What is air made of?

The Atmosphere Chapter 11

Layers of the Atmosphere The atmosphere is a mixture of gases that surrounds the Earth It provides us with the oxygen we need to breathe and protects us from the Sun’s harmful rays. The layers differ according to temperature and composition.

Earth’s Atmosphere is 78% Nitrogen 21% Oxygen 1% Argon and Carbon Dioxide Ozone (O3) exists in small quantities, absorbs ultraviolet (UV) radiation from the sun

Thermosphere- The upper-most layer; Temperature increases as altitude increases. Temperature can exceed one thousand degrees but it would still feel very cold. 80-1000km

Mesosphere- middle layer, coldest layer, temperature decreases as altitude increases. 50-80km

Stratosphere- the layer that contains the ozone layer- temp increases as altitude increases. 10-50km

Troposphere- lowest layer of the atmosphere; layer where we live and where all weather takes place. Temp. decreases as altitude increases. 0-10km

Temperature and Pressure Variation in the Atmosphere

Heat Transfer Heat is the energy transfer from one object to another because of a difference in temperature Temperature is a measure of the average energy of the individual atoms/molecules in a substance Measured in Fahrenheit (F), Celsius (C), and Kelvin (K)

Types of Heat Transfer

Radiation Radiation: transfer of energy through electromagnetic waves

Solar Radiation & The Earth 3 results of solar radiation hitting the Earth: Energy is absorbed by an object Energy travels through an object Energy is reflected by an object

Conduction Conduction: transfer of heat energy through a solid object Blacksmith heating metal to change its shape

Convection Convection: transfer of heat energy through movement of a liquid or gas Boiling Water

Wind Wind- the movement of air caused by differences in air pressure The greater the difference in pressure the faster wind moves

Humidity- The amount of water vapor in the air Relative humidity- is the amount of moisture in the air compared to what the air can "hold" at that temperature. When air is holding all the water it can at a given temp., it is said to be saturated. Measured with a psychrometer.

Dew Point- the temperature at which a gas condenses into a liquid Dew Point- the temperature at which a gas condenses into a liquid. At its dew point the air is saturated. It depends on temp. and the amount of water in the air

Condensation Change from a gas to a liquid Water vapor changes to form water droplets

Cloud Formation

Clouds A cloud is a collection of millions of tiny water droplets or ice crystals.

Cumulus clouds: Puffy, white clouds that tend to have flat bottoms Indicate fair weather When they get larger they can produce storm clouds called cumulonimbus clouds

Stratus clouds: Clouds that form in layers Cover large areas Nimbostratus clouds are dark stratus clouds that produce light to heavy continuous rain

Cirrus Clouds: Thin, feathery, white clouds Found at high altitude When they get thicker, it indicates a change in weather.

Alto- describes clouds at middle latitudes Cirro- describes clouds that form at high latitudes Nimbo- likely to produce precipitation Fog- a stratus cloud that formed close to the ground