The Atmosphere Earth’s Weather Heat Transfer ATMOSPHERE in MOTION The Atmosphere Earth’s Weather Heat Transfer

Atmosphere – What’s in it? Gases, water and other liquids, microscopic particles of solids Mixture of GASES Nitrogen – 78% Oxygen – 21% Argon - 0.93% Carbon Dioxide – 0.03% Aerosols Solids such as dust, salt, pollen, tiny acid droplets

Layers of the Atmosphere EXOSPHERE THERMOSPHERE MESOSPHERE STRATOSPHERE TROPOSPHERE

EXOSPHERE IONOSPHERE THERMOSPHERE MESOSPHERE STRATOSPHERE TROPOSPHERE 500 km (310 mi) IONOSPHERE aurora THERMOSPHERE meteors 80 km (50 mi) 60 km (37 mi) MESOSPHERE 45 km (28 mi) ozone STRATOSPHERE 10 km (6 mi) SEA LEVEL TROPOSPHERE

TROPOSPHERE 0-10 km Contains most clouds & weather Contains about 75% of the total mass of the atmosphere

STRATOSPHERE 10-50 km Contains OZONE – absorbs Sun’s ultraviolet radiation

UPPER LAYERS MESOPSHERE Coldest layer w/ little ozone THERMOSPHERE Warms as it filters out X-rays & gamma rays from sun, which have the shortest wavelengths, are absorbed by oxygen and nitrogen molecules Transformed into ions. EXOSPHERE Contains few atoms No clear boundary w/ space

UPPER LAYERS Ionosphere  Radio waves transmitted from the earth bounce off tiny energy particles called ions, return to a different location on the earth.

Atmospheric Temperature

Water filters through soil Condensation Precipitation Transpiration Leaves give off water Water filters through soil Evaporation Roots absorb water Groundwater Water Cycle

WATER CYCLE Water on our planet moves in a continuous cycle. water evaporates, heat is absorbed to form water vapor vapors rise, cool and condense into clouds. water droplets become heavy enough to fall -precipitation. water fills lakes, streams and rivers, and eventually flows back into the oceans where evaporation starts the process anew. transpiration by plant leaves: as plants absorb water from the soil, the water moves from the roots through the stems to the leaves, where it can evaporate.

EARTH’S WEATHER Temperature A measure of how fast air molecules are moving HIGH – molecules moving rapidly LOW – molecules moving slowly SCALE Freezing Point Boiling Point Fahrenheit 32 212 Celsius 0 100 Kelvin 273 373

Temperature Scales

Measurement of Water Vapor Humidity - the amount of water vapor in the air Temperature affects how much moisture is in the air Warmer air can hold MORE moisture – molecules are farther apart creating more space for the water molecules to fit in Dew point – The temperature at which water vapor will condense Relative Humidity – the amount of water vapor present compared to the amount that could be held at a specific temperature

AIR PRESSURE Weight of air column Warmer air is LESS DENSE – low pressure Cooler air is MORE DENSE – high pressure

AIR PRESSURE Device used to measure air pressure Barometer

CLOUDS – How do they form? Air rises Cools to its dew point through expansion (Less pressure, molecules spread out, heat is given off) Water vapor molecules "clump together" faster than they are torn apart by their thermal energy. Some of that (invisible) water vapor condenses to form (visible) cloud droplets or ice crystals.

CLOUDS

cloud particles become too heavy to remain suspended in the air PRECIPITATION Rain liquid precipitation Hail Ice precipitation Freezing rain super cooled droplets freezing on impact Sleet Frozen raindrops that bounce on impact with the ground Snow an aggregate of ice crystals cloud particles become too heavy to remain suspended in the air

Air moving from one temperature or pressure area to another WIND - Global Air moving from one temperature or pressure area to another Affected by Coriolis Effect apparent deflection of air to the right in the Northern hemisphere, to the left in the southern hemisphere caused by Earth’s rotation

WIND - Global Trade Winds  0 - 30 Prevailing Westerlies  30 - 60 Polar Easterlies  60 - 90 http://library.thinkquest.org/C001472/en/development/movement.content.html

Global Wind

WINDS – Local Sea Breeze Land heats up faster than the water Air above land heats up, becoming less dense and rises Cool, denser air from over water moves in

WINDS – Local Land Breeze Land cools faster than the water Air above land cools, becoming more dense and settles Warm air over water rises Cool air over land moves out and pushes warm air up

http://wings.avkids.com/Book/Atmosphere/instructor/heat-01.html

JET STREAM Bands of strong winds near the top of the troposphere at the northern and southern boundaries of the prevailing westerlies

Ocean Currents RELATED Movement of both  the air and the oceans is controlled by temperature differences The result is a transfer of heat from the equator to the poles.   About half the heat transport around the planet is by the oceans, making oceans an extremely important part of the Earth's climate control system.  If ocean circulation is changed by global warming, major changes in climate are therefore likely. 

Ocean Currents a Labrador Current b East Greenland C. c North Atlantic Drift d Gulf Stream e Canary C. f North Equatorial C. g Caribbean C. h South Equatorial C. i Benguela C. j Brazil C. k Falkland C. l West Wind Drift m West Australian C. n South Equatorial C. o Mozambique C. p Agulhas C. q Monsoon Drift r Kamchatka C./Oya Shio s Kuro Shio C. t North Pacific Drift u California C. v North Equatorial C. w Peru/ Humboldt C. x South Equatorial C. y East Australia C. z East Auckland C. Ocean Currents http://www.poemsinc.org/oceano/currents.htm

Greenhouse Effect The warming effect of the Earth’s atmosphere is called the greenhouse effect. Gases in the atmosphere that trap solar energy are called greenhouse gases Water vapor Carbon dioxide Methane Human Activities that ADD greenhouse gases: carbon dioxide (produced for example, by the burning of fossil fuels) nitrogen oxides (from car exhausts) Result – could be GOBAL WARMING

Possible effects of the global warming Positive Farmers in cooler regions could plant two crops a year Negative Higher temperature leads to water evaporating more quickly from soil – leading to “dust bowl” conditions Rise in ocean temperatures could spawn more hurricanes Rise in water temperatures would cause the water to expand, raising sea levels around the world Glaciers and polar ice caps might partially melt CFCs (from aerosols and refrigerators)

What is Ozone? Ozone is made of three oxygen atoms (O3). The oxygen we find in our atmosphere is made up of two oxygen atoms (O2). Because of its chemical formulation, a single atom of oxygen (O) is unstable. That is, it wants to combine with something else. That is why oxygen is almost always found in pairs, in its O2 (diatomic) form, where it is more stable. Ozone is less stable than O2, because it wants to return to the diatomic state by giving up an oxygen atom Ozone is unstable and will readily combine with other atoms. Ozone is found in the stratosphere, where it blocks the sun's ultraviolet (UV) waves and prevents them from reaching the earth's surface. Ozone is also found in the troposphere, where it can damage living tissue and human-produced objects. It is generated both from certain types of pollution and natural sources. Ozone is constantly being formed in the earth's atmosphere by the action of the sun's ultraviolet radiation on oxygen molecules. Ultraviolet light splits the molecules apart by breaking the bonds between the atoms. A highly reactive free oxygen atom then collides with another oxygen molecule to form an ozone molecule. Because ozone is unstable, ultraviolet light quickly breaks it up, and the process begins again. http://www.ucar.edu/learn/1_5_1.htm

Ozone (O3) Cause of thinning ozone layer Chemicals produced by humans CFCs (chlorofluorocarbons) from refrigerators, air conditioners, cleaners for electronic parts, spray cans Result Ultraviolet radiation breakdown CFC molecules into atoms, including chlorine (Cl) Chlorine breaks ozone down into oxygen atoms

Air Pollution Harmful substances in the air Some is naturally occurring – pollen, volcanic ash Much is caused by human activity Most is a result of burning fossil fuels Coal, oil, gasoline, diesel fuel ≈ ½ comes from motor vehicles (trucks, buses, cars, lawn mowers, scooters ≈¼ comes from electric power plants and factories burning coal and oil

SMOG Photochemical Smog Caused by the action of sunlight on chemicals Nitrogen oxides – Nitrogen Oxide (NO) produced from burning fossil fuels reacts with oxygen in the atmosphere to make Nitrogen Dioxide (NO2) Hydrocarbons – organics given off by some plants, from fuels evaporating and incomplete burning of fuel These along with others react with each other in the presence of sunlight to form a mix of ozone and other chemicals SMOG

SMOG http://www.osc.edu/research/pcrm/transport/ozone.shtml

ACID RAIN – What is it? Sulfur dioxide (SO2) and nitrogen oxides (NOX) released into the air from burning fossil fuels. Combined with water and other chemicals, sulfur and nitrogen oxides become sulfuric and nitric acid. These acids may travel long distances before falling to the earth as rain, snow, sleet, hail, fog, dew or dust.

ACID RAIN – How do you know? Acid rain is measured using the pH scale. The pH scale ranges from 0 (very acidic) to 14 (most alkaline). Seven is neutral. Rain is by nature slightly acidic, with a pH of 5.6. Any precipitation below that is considered "acid rain". Because the scale is logarithmic, a pH of 4.6 is ten times more acidic than normal rainwater and a pH of 3.6 is a hundred times more acidic. The average pH of rain in Vermont is between 4.2 and 4.4 with extremes ranging from 2.4 to 7.4.

Vermont

ACID RAIN – Solutions? SCRUBBERS - filters in smokestacks of factories and power plants to remove pollutants Very expensive to install. USE ALTERNATIVE ENERGY PRODUCTION METHODS – Wind or solar power not harmful to the environment. However, the cost of replacing all of the fossil fuel power stations with either wind farms or solar power is prohibitive and almost impossible. It would take 600 wind turbines to produce the same electricity as one coal-fired power station. USE LESS ENERGY – insulate houses better, lower ceilings, use the car less, walk more, bicycle, public transportation CATALYTIC CONVERTERS - catalytic converters on car exhausts remove around 90% of the pollutants released during the combustion process.