Size of Earth’s Atmosphere

Air

•invisible, odorless, colorless and tasteless

• extends out 10,000 km (6000 miles)

•98% is within 26km (16 miles) of sea level

• held by gravitational force

• makes life possible (oxygen for animals, carbon dioxide for plants)

• maintains water supply

• insulates us against extreme temperatures

•shields us from ultraviolet radiation

Atmospheric Gases

Composition of the Atmosphere

Composition of the AtmosphereGases

Nitrogen 78 %

Oxygen 21 %

Argon 0.9 %

Neon HeliumKryptonHydrogen } Total < 0.09 %

Important variable amount gases

Water vapor (H2O)Carbon dioxide (CO2)Carbon monoxide (CO)Methane (CH4)Ozone (O3)Sulfur dioxide (SO2)Nitrogen dioxide (NO2)

Composition of the Atmosphere

Atmospheric Particulates

More particulates: smoke from wild fires, meteorite debris, pollen grains, oceanic salt spray, volcanic ash, industrial emissions, dust storms, etc.

Composition of the Atmosphere

Natural

Human-induced

Atmospheric Pressure

Vertical Structure of the Atmosphere

Thermal Layers of the Atmosphere

Meanings

Exosphere = outer

Thermosphere = heat

Mesosphere = middle

Stratosphere = layers

Troposphere = mixing

Each warm zone has a specific source of heat:

Thermosphere - atoms and molecules absorbing UV and being split

Stratosphere - ozone layer absorbs UV

Visible light - absorbed by surface and lowest layer of troposphere

TroposphereTroposphere:•Layer where weather occurs

•Extends 8-18 km (5-11 mi) outwards from the surface

•Deeper in summer and at tropics

Stratosphere - where the Ozone Layer is found

Atmospheric Composition

•Heterosphere: beyond 80 km (50 mi) the gases are layered according to molecular masses

•heterogenous composition

•Homosphere: throughout lowest 80 km (50 mi) the gases are distributed uniformly

•homogenous composition

Division of the Atmosphere

Based on chemical

composition

Based on temperature

(thermal layers)

Based on function

Homosphere (0-50 miles)

Heterosphere (beyond 50 miles)

Troposphere: to 11 miles Stratosphere: 11-30 miles

Mesophere:30-50 miles

Thermosphere: 50 miles out, turning into exosphere

Ozonosphere (9-30 miles)

Ionosphere (40-250 miles)

Ozone absorbs UV radiation, protecting us from the sun

Deep layer of electrically charged molecules and atoms (ions) important in long-distance communications (radio waves) and for aurora displays

Natural Ozone Formation

Human-Induced Atmospheric Change

Ozone Destruction by CFCs

Ozone hole over Antarctica

Human-Induced Atmospheric Change

Consequences:1. the “hole” in the ozone layer (UV-B, UV-C)

2. acid rain and smog (airborne pollution)

3. Ventura County’s worst offenders = particulate matter and ozone pollution

Associated health problems:

respiratory diseases

skin cancers

Depletion of Ozone Layer video

Human-Induced Atmospheric Change

Ozone Loss over the PolesCFCs originate in Northern Hemisphere

redirected by winds (toward poles)

stratospherehigh, thin cloud cover

cold temperatures

Chlorine atoms freed at high rates (poles)

“hole” over Antarctica larger than Arctic

Mid-lats also experiencing ozone thinning

UV passes to Earth’s surface

Definitions

Weather: short-term atmospheric conditions that exist in a specific location during a specific time

Climate: long-term atmospheric conditions that exist in a location, localized or broad, during a prolonged period of time

Weather/climate and the troposphere

Weather and Climate

Elements of Weather and Climate

Weather and Climate

Controls of Weather and Climate

Weather and Climate

Latitude

General Circulation of the Atmosphere

General Circulation of the Oceans

Elevation/Altitude

Topographic Barriers

Storms

Coriolis Effect

Coriolis effect: the apparent horizontal deflection of free-moving objects in response to the rotation of the Earth •Northern Hemisphere: to the right

•Southern Hemisphere: to the left

•deflection is strongest at the poles

•deflection is zero at the equator

•the faster the object, the more deflection

•direction of movement affected, not speed

Coriolis Effect video

Coriolis Effect

Homework1. Have syllabus & textbook?

ADD SLIPS – list/sign.

2. Read Chapter 3.

3. HW #1• Define the UV Index.

• Why is it important?

• Summarize, image, or alternative.

Note: All homework due… the

next week (or) before the midterm.Sub-tropical storm over Ventura County