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

Composition of the Atmosphere Atmospheric Gases

Composition of the Atmosphere Gases Nitrogen 78 % Oxygen 21 % Argon 0.9 % Neon Helium Krypton Hydrogen Important variable amount gases Water vapor (H2O) Carbon dioxide (CO2) Carbon monoxide (CO) Methane (CH4) Ozone (O3) Sulfur dioxide (SO2) Nitrogen dioxide (NO2) } Total < 0.09 %

Composition of the Atmosphere Atmospheric Particulates

Composition of the Atmosphere More particulates: smoke from wild fires, meteorite debris, pollen grains, oceanic salt spray, volcanic ash, industrial emissions, dust storms, etc. Human-induced Natural

Vertical Structure of the Atmosphere Atmospheric Pressure

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

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

Natural Ozone Formation Human-Induced Atmospheric Change Natural Ozone Formation

Ozone Destruction by CFCs Human-Induced Atmospheric Change Ozone Destruction by CFCs Ozone hole over Antarctica

Human-Induced Atmospheric Change Consequences: the “hole” in the ozone layer (UV-B, UV-C) acid rain and smog (airborne pollution) Ventura County’s worst offenders = particulate matter and ozone pollution Associated health problems: respiratory diseases skin cancers Depletion of Ozone Layer video

Ozone Loss over the Poles CFCs originate in Northern Hemisphere redirected by winds (toward poles) stratosphere high, 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

Weather/climate and the troposphere Weather and Climate 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

Elements of Weather and Climate

Controls of 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

Homework 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