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OU GEOG 1114 - Solar Energy

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GEOG 1114 1st Edition Lecture 8Outline of Last Lecture -Atmospheric Composition- based on gas distribution -Human Induced Atmospheric change -Weather and Climate -Solar energy (Insolation) and temperature-Electromagnetic Radiation (EMR) -Electromagnetic Spectrum Outline of Current LectureSolar Energy (Insolation) and Temperature continued…-Review of last lecture-Processes of heating and cooling -Spatial and Seasonal Variations in the Heat Budget -Latitudinal Differences Current Lecture Review: -Sun-Major source of energy for planet-EMR spectrum- 50% visible-Balance between incoming shortwave insolation and outgoing longwave -Some shortwave radiation reflected by atmosphere or surface -Albedo- the reflectivity of an object These 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.Basic Processes of Heating and Cooling:Radiation – processes by which heat is emitted by a body-Warmer objects radiate more effectively (hotter)-Warmer objects emit shorter wavelengths-Sun ultimate hot body How (Radiation) Energy Interacts with an Object:Absorption -Body absorbs radiation-Good radiator, good absorber (water, sand)Reflection-Objects repel EMR (reflect back)-Size, material, condition, portion of spectrum-play a role -Good absorbers reflect little-Snow on a warm day reflect a lot of energy Scattering-Deflection of light waves by molecules and particles (dust, water) -Wavelength dependent -Blue portion most scattered; hence blue sky -Sun sets- dust, Electromagnetic radiation EMR travels a longer distance, reduced angle- more scattering of orange and redTransmission-Electromagnetic waves pass completely through a medium -Water-good transmitter -Atmosphere-Transmits shortwave radiation wellTransmission of energy and the greenhouse effect:Greenhouse Effect-Some atmospheric gases transmit shortwave radiation, but not earth’s longwave radiation -Earth radiation held in by the atmosphere-Atmospheric blanket*Same effect in happens in cars How Energy is moved?Conduction -Movement of heat from one molecule to another -Results from molecular collision -Air is a poor conductor, metal is good -Allows heat to be transferred from one abject to another Convection -Heat transfer by vertical circulation- Molecules move in tandem -Convection cellAdvection-Horizontal transfer of heat -In the atmosphere wind may transfer warm or cool air horizontally Adiabatic Cooling & Warming (vertical changes in temperature)Adiabatic Cooling:-Air rises and expands (due to pressure changes) molecular collisions decrease, so temperature decreases -Heat is dispersed; air pressure decreases *This rate can be accelerated with storm activity Adiabatic Warming:-Air sinks (descends) and compresses; collisions increase so temperatures increase -Increased pressure Changes in the storage and release of energy:Evaporation: Liquid water is converted to a gaseous water vapor-Rates depend on temp. Location, pressure-Cooling process-energy is stored Condensation: Water vapor changes to liquid-Warming process-Energy is released-sensible heat (latent heat) Latent Heat: Heat is released or absorbed during a phase change-“Latent” since heat is not felt -Most common phase changes: Evaporation and Condensation *The global heat budget is being interrupted by human activity Spatial and Seasonal Variations in the Heat Budget:-The Heat Budget of the earth is a broad generalization on heat transfer and movement through the atmosphere-There are considerable imbalances, both vertically through the atmosphere and horizontally over the earth’s surface.-It’s these differences that cause weather and climate variationsLatitudinal Differences:-Angle of incidence (latitude) – angle at which rays strike the earth. -Yearly – poles receive fewer amounts-Variable heating sets up unstable conditions*Most of the evaporation happens at the equator Day Length (latitude and tilt) (tied to seasons and latitude) we tilt – longer days more insolation; evaporation, absorption, etc. Atmospheric Obstruction – clouds, water vapor, gas, dust – reduce intensityMigration of the SunThe direct rays of the sun shift northward and southward across the equator during the course of the year. This belt of maximum energy swings through the tropics (213.5 N to 23.5 S)Within this tropical belt – there is an energy surplusIn latitudes N/S of tropics there is a deficit increasing pole


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