Transcript Unit 4, Part 1 Notes

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 object
2.) 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
Temperature Controls
Book page 488 (charts)
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.