chapter 4: insolation and temperature

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Chapter 4: Insolation and Temperature. The Impact of Temperature on the Landscape. All living things influenced by temperature Adaptation to temperature extremes Temperature affects human-built landscape Temperature affects inorganic landscape components Soil and bedrock exposure. - PowerPoint PPT Presentation

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Chapter 1: Introduction to Earth

Chapter 4: Insolation and Temperature

The Impact of Temperature on the LandscapeAll living things influenced by temperatureAdaptation to temperature extremesTemperature affects human-built landscapeTemperature affects inorganic landscape componentsSoil and bedrock exposureFigure 4-1a & 4-1b

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Energy, Heat, and TemperatureEnergy: ability to do workForms of energyKinetic energy of movementChemical, Potential, Nuclear, etc.TemperatureHeatMovement of atomsTemperature:Measurement of heatTemperature scalesCelsiusFahrenheitKelvin

Figure 4-2

3

Energy, Heat, and TemperatureThe SunPrimary source of energy for Earths atmosphereProperties of SunAverage size starNuclear fusionMagnitude of Suns energyEnergy spreads as it leaves the SunTravels through voids in space without loss of energyFigure 4-3

4

Energy, Heat, and TemperatureElectromagnetic (EM) energyEM spectrumWavelengthDistance between two wave crests3 important areas of EM spectrumVisible radiationUltraviolet radiationToo short to be seen by the human eyeInfrared radiationToo short to be seen by the human eyeFigure 4-5

Figure 4-45InsolationIncoming solar radiationShortwave energyTerrestrial EnergyLongwave energyEarths energy

Energy, Heat, and Temperature

Figure 4-16

Basic Heating and Cooling Processes in the AtmosphereRadiationWhen objects emit EM energyAKA Heat energy emitted from a bodyWarmer objects radiate more effectivelyWarmer objects emit at shorter wavelengths

Figure 4-67

Basic Heating and Cooling Processes in the AtmosphereAbsorptionBody absorbs radiationGood radiator, good absorberReflectionObjects repel electromagnetic wavesOpposite of absorptionFigure 4-7

8

Basic Heating and Cooling Processes in the AtmosphereScatteringDeflection of light waves by molecules and particlesTransmissionElectromagnetic waves pass completely through a mediumSunsets

Figure 4-9

9

Basic Heating and Cooling Processes in the AtmosphereGreenhouse effectSome atmospheric gases transmit shortwave radiation, but not Earths longwave radiationEarth radiation held in by atmosphereAtmospheric blanket

Figures 4-11 & 4-12

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Basic Heating and Cooling Processes in the AtmosphereConductionTransfer of heat energy across a mediumEnergy moves from molecule to another one without changing molecular positionsAKA direct heat transfer by contactMolecules become agitated, then vibrate & collide with cooler molecules, transferring heat energy

Figure 4-13

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Basic Heating and Cooling Processes in the AtmosphereConvectionHeat transfer by vertical circulation in a moving substanceVertical convection cellWarm air gains heat, expands & risesCool air loses heat, contracts & sinksAdvectionHorizontal transfer of heat in a moving fluidAKA wind

Figure 4-1412

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Radiation, Conduction & Convection Operating Simultaneously

Basic Heating and Cooling Processes in the AtmosphereAdiabatic Cooling and WarmingChange in pressure & thus temperature of rising or descending airAdiabatic coolingAir rises and expands, molecular collisions decrease, so temperature decreasesAdiabatic warmingAir sinks and compresses, collisions increase so temperatures increase

Figure 4-15

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Basic Heating and Cooling Processes in the AtmosphereLatent heatHeat released or absorbed during a phase changeAKA hidden heat since latent heat is not feltEvaporation: liquid water is converted to water vaporCooling processCondensation: water vapor is converted to liquid waterWarming process

15

The Heating of the AtmosphereBalance between shortwave incoming solar radiation & outgoing longwave solar radiationAlbedoThe higher the albedo, the more radiation the object reflects

Figure 4-16

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The Heating of the Atmosphere: Global Energy BudgetEnergy in = Energy out

Figure 4-171718Earth does not distribute heat evenly through space & timeCause of weather and climate

The Heating of the Atmosphere: Global Energy Budget

Variations in Heating by Latitude and SeasonAngle of incidenceAngle the Suns rays strike Earths surfaceThe higher the angle, the more intense the radiation

Figure 4-18

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Variations in Heating by Latitude and SeasonAtmospheric obstructionsClouds, haze, particulates, etc. decrease insolation

Figure 4-20

Figure 3-420

Variations in Heating by Latitude and SeasonDay lengthThe longer the day, the more insolation is received

Figure 4-1921

Variations in Heating by Latitude and SeasonLatitudinal radiation balance and the world distribution of insolationBelt of max solar energy that moves through the tropics following the Suns direct rays

Figure 4-2122

Land and Water ContrastsLand heats and cools more rapidly than water due to:Specific heatTransmissionMobilityEvaporative cooling

Figure 4-23

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Land and Water Contrast ImplicationsOceans = more moderate climatesHottest & coldest places on Earth are interiors of continentsN. (land) vs. S. (water) Hemisphere

Figure 4-2424

Mechanisms of Heat TransferNeed heat transfer to prevent constant warming at tropics & cooling at polesCirculation patterns in atmosphere and oceans transfer heat

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Mechanisms of Heat Transfer2 mechanisms move heat poleward in both hemispheres, driven by latitudinal imbalance of heatAtmospheric circulation (Ch 5)Oceanic circulationDirect relationship between atmospheric and oceanic circulationAir blowing over the ocean creates major surface ocean currentsHeat energy stored by oceans affects atmospheric circulation

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Mechanisms of Heat TransferNorthern and southern variationsNear N. Hemisphere pole, landmasses lie so close that little flow can enter the Arctic OceanIn S. Hemisphere, little land mass allows for constant westward belt of ocean circulation called West Wind DriftSouthern Ocean (AKA the 5th Ocean)

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Mechanisms of Heat TransferTemperature patternsPoleward currents transfer warm water polewardEquatorial currents transfer cool water equatorwardFigure 4-25

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Mechanisms of Heat TransferRounding out the patternNW portions of N. Hemisphere receive cool water from Arctic OceanWater pulled away from western coasts of continents = upwellingDeep ocean circulationGlobal conveyor beltTied to short-term climate change

Figure 4-2629

Vertical Temperature PatternsEnvironmental lapse rateNormal vertical temperature gradientAverage lapse rate 6.5C/km or 6.5C/1000m)Temperature inversionsSurface inversionsUpper air inversions

Figures 4-27 & 4-28

3031Global temperature mapsSeasonal extremesJanuary & JulyBROAD understanding of temperature patternsIsotherm: line connecting points of equal temperature

Global Temperature Patterns

Global Temperature PatternsPrimary controls on global temperatureAltitudeTemperature decreases with altitudeLatitudeFundamental cause of temperature variationTemperature with latitudeLandWater contrastsContinents have higher summer & lower winter temps than oceansOcean currentsCool currents push isotherms equatorward; warm currents push isotherms polewardFigure 4-29 average January temperatureFigure 4-30 average July temperature

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Global Temperature PatternsSeasonal patternsLatitudinal shift in isotherms from one season to anotherMore pronounced over continents than water and over high latitudes than low latitudes

Figure 4-31

33

Global Temperature PatternsAnnual temperature rangeDifference in average temperature of warmest and coldest months (usually Jan & July)

Figure 4-3234

Global Warming and the Greenhouse EffectClimate of Earth is becoming warmer, known as global warmingAir temp increases when atmospheric gases trap longwave radiationHuman-enhanced greenhouse effectCarbon dioxide main culpritAlso methane, nitrous oxide, CFCsIntergovermental Panel on Climate ChangeFigure 4-33

35

Global Warming and the Greenhouse EffectRelationship between carbon dioxide and temperature

Figure 4-35

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SummaryTemperature affects both living and nonliving aspects of Earths landscapeEnergy exists in many different forms, but cannot be created or destroyedTemperature is a measure of the amount of kinetic energy in the molecules of a substanceTemperature is measured on three primary scalesThe Sun is the primary source of energy for Earths atmosphereElectromagnetic radiation is classified by wavelengthThe Sun emits three important types of electromagnetic radiation: visible, infrared, and ultravioletInsolation refers to incoming solar radiationRadiation is the process by which electromagnetic radiation is emitted by an objectRadiation can undergo several processes, including absorption, reflection, transmission, and scatteringThe greenhouse effect makes Earth able to support life37

SummaryConduction is the transfer of heat through molecular collisionConvection is a vertical transport of heat in a fluidAdvection is the horizontal transport of heatAdiabatic cooling and warming processes do not release or absorb heatThe global radiation budget describes the latitudinal distribution of temperatureLand surfaces heat and cool faster than water surfacesHeat is transferred globally through atmospheric and oceanic circulationsThe vertical temperature patterns in the atmosphere help describe vertical circulationsGlobal warming is the observed warming of the atmosphereTemperature and carbon dioxide show a close relationship38

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