Lecture 3Outline of Last Lecture I. MoleculesII. Atmospheric PressureIII. How much does air weigh?IV. Pressure and HeightV. Air DensityVI. Surface Weather MapVII. Atmospheric TemperatureVIII. TroposphereIX. TropopauseX. StratosphereXI. MesosphereXII. ThermosphereOutline of Current Lecture XIII. Conservation of EnergyXIV. TemperatureXV. Temperature and DensityXVI. Heat EnergyXVII. Phases of WaterXVIII. Phase ChangesXIX.Heat TransferXX. Solar HeatingXXI. Rising Air and TemperatureCurrent LectureXXII. Conservation of EnergyATMS 100 1st Editiona. energy can be neither created nor destroyedi. energy is conservedb. Energy can be transferred between different formsThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.i. as an object falls, its potential energy is transferred to kinetic energyc. when the object stops, the kinetic energy is transferred to heatXXIII. Temperaturea. measure of the average speed of the molecules of a substancei. some molecules move faster, others move slowerb. when the molecules within an object absorb energy, they move fasteri. the temperature of the object increasesii. more energetic collisions between moleculesXXIV. Temperature and Densitya. warm is is less dense (prone to wise)b. cold air is more dense (prone to sink)XXV. Heat Energya. sensible heat: i. heat that can be sensed or measured witha termometerb. latent heat:i. the energy absorbed or released during a phase change1. “hidden energy”XXVI. Phases of Watera. on earth, water exists naturally in all three phases: sold, liquid, and gasXXVII. Phase Changesa. Evaporation: water to gasb. Condensation: gas to liquid (rain)c. Sublimation: ice to gas (frost going away on its own) d. Deposition: gas to solid (scraping frost of your windowe. Cooling Processes (in terms of energy)i. melting, evaporation, sublimation 1. latent heat is absorbedf. Warming Processes (in terms of energy)i. Freezing, Deposition, Condensation1. latent heat is releasedXXVIII. Latent Heata. released via condensation powers many weather systemsi. a single thunderstorm releases several times more energy in one hour via condensation than the atomic bomb dropped in Japan in 1945XXIX. Heat Transfera. conduction:i. direct transfer of heat within the substance (or from one substance to another)ii. heat always flows from hot to coldiii. good heat conductors1. metals2. transfer heat efficientlyiv. poor heat conductors (good insulators)1. air, water, wood, plastic, fiberglass2. transfer heat b. convection:i. transfer of heat through fluid flowii. fluid flow= air (or water) currentsiii. generally refers to vertical motions onlyiv. air and water are both fluidsc. advectioni. transfer of heat (or moisture) through horizontal movements of air1. sea or lake breezeXXX. Solar Heatinga. air is largely transparent to sunlighti. sun does not heat the air directlyii. clear sky=transparentiii. hazy sky=not transparentb. sun heats the surfacec. thin layer of air (1 cm or so) just above the surface is heated by conductioni. right next to the hot groundd. this hot air expands, become less dense, and begins to risei. hot, less dense air rises, like helium balloonsii. this rising air transports heat upward from the surface (convection)e. the troposphere is heated from the bottom upf. blobs (parcels) of hot air rise, like helium balloonsi. transport heat upward from the surface (convection)g. cooler air from aloft sinks and is later heated by surfaceXXXI. Rising Air and Temperaturea. think of a blob of air about the size of this room i. this is called an air parcelb. as hot air parcel rises, the pressure around it decreases, and the air parcel expandsi. pressure always decreases with heightXXXII. Sinking Air and Temperaturea. as an air parcel sinks, the pressure around it increases, so the air parcel is compressedi. pressure alwasy increases as you go down toward the surfaceb. compression transfers energy to the