Earth Science Exam 4 Outline I The Atmosphere A States of Water 1 Solid solid to a gas 2 Liquid Freezing Liquid to a solid 3 Gas gas to a solid B Transitional Processes and Energy Dynamics 1 Melting solid to a liquid 2 Evaporation conversion of a liquid to a gas 3 Sublimation solid to a gas 4 Condensation water vapor converts to a liquid 5 Freezing Liquid to a solid 6 Deposition gas to a solid C Concept of Latent Heat heat energy not associated with a temperature change Latent Heat of Evaporation heat energy absorbed by water to turn molecules into a gas Latent Heat of Condensation heat energy released by water vapor to return to liquid Latent Heat of Melting Heat energy absorbed by Ice to return water to liquid Latent Heat of Freezing fusion heat energy released to form ice from liquid D Water Vapor in the Air 1 Humidity a relative humidity he ratio of air s actual water vapor content to its potential water vapor capacity mixing ratio at a given temperature actual water vapor content X 100 mixing ratio b Air Saturation When the number of molecules leaving the number of molecules returning More molecules required at higher temperatures therefore more moisture required at higher temps c What happens if Temperature decreases If water vapor content is constant then a decrease in temperature results in an increase in relative humidity This is because at lower temperatures saturation vapor density decreases E Cloud Formation 1 Adiabatic Temperatue changes temperature changes that occur without heat being absorbed or released a Dry adiabatic rate Unsaturated air cools at 10oC every 1000 feet ascent heats 10oC every 1000 feet descent This is known as dry adiabiatic rate b Wet adiabatic rate Once air rises high enough it cools off enough to start condensing which releases latent heat This heat reduces the adiabatic cooling rate to about 5oC every 1000 feet ascent dependingonmoisturecontentofair Moistaircoolslessrapidlyduetolatentheatof condensation F Processes That Lift Air 1 Orographic liftingair is forced to rise over a mountainous barrier 2 Frontal Wedging warmer less dense air is forced over cooler denser air 3 Convergence a pileup of horizontal air flow results in upward movement 4 Localized Convective Lifting unequal surface heating causes localized pockets of air to rise because of their buoyancy II Global Warming and the Greenhouse Effect A Intro to Greenhouse Effect and Global Warming 1 Definition of Global Warming The Intergovernmental Panel on Climate Change a policy advisory group made up of members of the World Meteorological Organization and the United Nations Environment Program estimates that the average global surface temperature could climb anywhere from 1 4 to 6 4 C by the year 2100 The average surface temperature of the earth has increased during the twentieth century by about 0 6 to 0 8 C 0 4 degrees in past 25 years alone This may seem like a small shift but although regional and short term temperatures do fluctuate over a wide range global temperatures are generally quite stable In fact the difference between today s average global temperature and the average global temperature during the last Ice Age is only about 5 C B Mechanisms of Heat Transfer 1 2 Conduction Convection 3 Radiation B Electromagnetic Spectrum D Results of Radiation Striking Objects 1 Energy Absorbed 2 Energy Redirected a albedo fraction of the total radiation that is reflected by a surface E Process of Greenhouse Effect how it occurs II Global Warming and the Greenhouse Effect cont F Greenhouse Gases in the Atmosphere 1 Activities that produce greenhouse gases 2 Carbon Cycle Deforestation when wood is burned the carbon contained in the trees is released as carbon dioxide When wood rots in swamps methane can be produced Living trees remove carbon dioxide from the atmosphere Carbon Cycle 3 Human Contributions to Greenhouse gases a energy use b industrial production c deforestation d agriculture G Global Warming 1 Global average increase in temperature a Correlation of temperature to increase in greenhouse gases The 8 warmest years have occurred since 1998 Earth s surface temperature has risen 0 8 C 1 4 F in last 140 years 2 Consequences of Global Warming I Climate changes increased warming a Shifts in agricultural belts b ecosystem shifts and species die off II Melting of glaciers and ice sheets 1 changing of ocean currents thermohaline circulation 2 elimination of arctic food web III Sea level rise Current rates of sea level rise are expected to increase as a result both of thermal expansion of the oceans and melting of most mountain glaciers and partial melting of the West Antarctic and Greenland ice caps Consequences include loss of coastal wetlands and barrier islands and a greater risk of flooding in coastal communities Low lying areas such as the coastal region along the Gulf of Mexico and estuaries like the Chesapeake Bay are especially vulnerable IV Extreme Weather Events H What we can do to help 2 400 pounds of carbon dioxide annually 1 Reduce reuse recycle By recycling half of your household waste you can save 2 Use less heat and air Setting your thermostat just 2 degrees lower in winter and higher in summer could save about 2 000 pounds of carbon dioxide each year 3 Change a lightbulb Wherever practical replace regular light bulbs with bulbs Replacing just one 60 watt incandescent light bulb with a compact fluorescent light CFL will save you 30 over the life of the bulb CFLs also last 10 times longer than incandescent bulbs use two thirds less energy and give off 70 percent less heat If every U S family replaced one regular light bulb with a CFL it would eliminate 90 billion pounds of greenhouse gases the same as taking 7 5 million cars off the road 4 Drive less Every gallon of gas you save not only helps your budget it also keeps 20 pounds of carbon dioxide out of the atmosphere Switching from a regular car to an SUV for a year wastes the same energy as Letting your fridge open for six years Left your bathroom light burning for 30 years 5 Buy efficient products Buy a car that offers good gas mileage Home appliances energy efficient models Avoid products that come with excess packaging especially molded plastic and other packaging that can t be recycled If you reduce your household garbage by 10 percent you can save 1 200 pounds of carbon dioxide annually 6 Turn off lights Turn off lights when you leave a room and using only as much light as you need And remember to turn off your