Atmospheric Characteristics

Weather vs. Climate

Weather:

Constantly changing, refers to the state of the atmosphere at any given place and time.

Climate:

Observations that have been based over many years. (Describes a place or region)

Properties that we measure

For both Weather and Climate Rainfall

Air Temperature Humidity

Type/Amount of Precipitation Air Pressure

Speed/Direction of Wind

Composition of the Atmosphere

Major Components:– Nitrogen– Oxygen– Argon/Carbon Dioxide

Variable Components:– Water Vapor– Dust Particles– Ozone

Water Vapor

The source of all clouds and precipitation.

Absorbs heat and energy given off by Earth.

Ozone

Q.) What does it do? How do you know?

A.) Protect us from harmful rays; allows for all the different types of life to be on our planet.

Air Pollutants

Three types:

1.) Primary – Emitted from and identifiable source.

2.) Secondary – Not directed into the air.

3.) Photochemical – Reactions by sunlight.

Height of the Atmosphere

Q.) Where does the atmosphere end and space begin?

A.) It thins as you travel up until there are to few gas particles to protect.

Structure of the Atmosphere

Pressure Change: – The weight of the air

above– Heavy to light

Temperature Change:– Hot to cold

Layers of the Atmosphere

Four Layers:– Troposphere: Temp

goes down when altitude goes up.

– Stratosphere: Ozone is here, Temp increases.

– Mesosphere: Temp goes down

– Thermosphere: Temp increases/little amount of atmosphere.

Earth Movements!

Earth Motions:

1.) Rotation: Spinning around on the axis (day)

2.) Revolution: Around the orbit (year)

Earth’s Orientation

Cause for different seasons:– Summer Solstice (June 21 – 22)– Autumnal Equinox (September 22 -23)– Winter Solstice (December 21 – 22)– Vernal (Spring) Equinox (March 21 – 22)

Heating the Atmosphere

Heat vs. Temperature

Heat: Energy transferred from one object to another; a difference in temperature.

Temperature: The measure of the average energy in an individual object.

Energy Transfer (Heat) Three ways:

1.) Conduction

2.) Convection

3.) Radiation

Conduction

The transfer of heat through matter by activity

I.E. – Molecules hitting each other!

Heat flows from high to low!

Convection Heat transfer: mass

movement or circulation within a substance

Ex. Water boiling in a pot

Radiation Can travel through space!

Four Laws:

1.) All object emit radiant energy.

2.) Hotter emits more than cold.

3.) Hottest bodies shortest wavelengths.

4.) Absorb and emit radiation.

Electromagnetic Waves

The sun is the ultimate source of energy!

Different waves have different wavelengths

Solar Radiation Three different

results: 1.) Energy absorbed by an object2.) Energy is not contributed to the object.3.) Energy can bounce of an object.

Reflection vs. Scattering

Reflection: Light bounces off an object

Scattering: Weather rays that travel in different directions.

Absorption

Clouds absorb solar energy and heat up the atmosphere

Greenhouse Effect: When air stays heated to help maintain life on Earth

Book page 488 (charts)

Temperature Controls

What is it?

Any factor that causes temperature to vary from place to place and from time to time.– Differences in receipt of solar radiation (variation in the

angle of solar rays, length of day, latitude) Other factors include:

– Heating of Land and Water– Altitude– Geographic Position– Cloud Cover– Ocean Currents

Land and Water

Land– Heats more rapidly

and higher temps– Cools more rapidly

and to lower temps– Higher temp

variations

Water– Heats and cools

slowly and has more regulated temperatures

Geographic Position

Costal Location – – Windward = wind blows onto shore

Cool summers and mild winters California Coast

– Leeward = wind blows toward ocean More continental patterns of weather New York Coast

Altitude

Elevation from sea level

Cloud Cover and Albedo

Albedo and cloud cover relate Day

– Clouds have a high albedo and reflect back a large portion of the sunlight back into space.

– Influences temp in the lower atmosphere

Night– Clouds act as a blanket keeps solar radiation in – Cloudy nights are warmer then clear nights

Isotherms

Allows to study global temperature patterns Effects of he controlling factors of temp

– Especially latitude– Distribution of land and water– Ocean currents

Trend east to west and shows a decrease in temps from the tropics to the poles

Water in the Atmosphere

The Key!

Water Vapor

Causes condensation and precipitation

Sates of Water

Three:

1.) Solid

2.) Liquid

3.) Gas

Terms to Know

Latent heat: Used to melt ice that does not produce a temperature change. (Hidden)

Evaporation – Liquid to gas

Condensation – Water vapor changes to liquid

Sublimation vs. Deposition

Solid right to a gas Vapor directly to a solid

Humidity

How much water vapor is in the air.

Types: – Saturation– Relative Humidity– Dew Point– Measuring Humidity

Saturation

When warm air contains more water vapor than cold air

Ex. Water leaving will equal water in the atmosphere

Relative Humidity

A ration of the actual water vapor content compared to the amount of water vapor air can hold.

Lower air temp = increase RH

Raising air temp = decrease in RH

Dew Point

The temp at which a parcel of air would need to be cooler to reach saturation.

Measuring Humidity

Hygrometer – most common way to measure humidity

Cloud Formation

Temperature Change

Adiabatic Temp Change – When air is allowed to expand (cools); compresses (warms)

Dry = Cooling and Heating

Wet = Latent Heat + cooling and heating

Lifting the Air?

Types: – Orographic Lifting– Frontal Wedging– Convergence– Convective Lifting

Orographic Lifting

Elevated terrains act as barriers

Ex. Mountains

Frontal Wedging Front – Warm air and

cool air combine

Helps to keep North American wet!

Convergence

When the atmosphere flows together it rises.

Ex. Florida peninsula has lots of thunderstorms in the afternoon

Convective Lifting

The heating and lifting of air, creating thermals.

Ex. Birds use them, hang gliders use them

Air Stability

Stable air remains in place.

Unstable air tends to rise.

Ex. Hot air balloon

Measurements

Radiosondes – collects weather data in the atmosphere.

Measures the environmental lapse rate.

Temperature Inversion

Air temperature increases with height.

On nights when the cold air is inverted to the top and warm air to the bottom.

Stable vs. Unstable

Stable = little to no weather.

Unstable = lots of weather

Condensation

The air has to be saturated for condensation to form.

Condensation Nuclei – a surface for water vapor to attach too.