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Where it all starts . THE SUN. Mars – too thin , so it doesn´t absorb enough heat Venus – so dense, the heat doesn´t escape! Earth – the perfect combination !!! Some of the sun´s energy is absorbed by the atmostphere Some is absorbed by the planet´s land and water
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Whereitallstarts. THE SUN
Mars – toothin, so itdoesn´tabsorbenoughheat • Venus – so dense, theheatdoesn´t escape! • Earth – theperfectcombination!!! • Some of thesun´senergyis absorbed bytheatmostphere • Someis absorbed bytheplanet´sland and water • Someisreflected back intospace • Ifwekeeppollutingouratmospherecouldbecomethick and dense likeVenus´satmosphere!!! Ouratmosphereallowsourplanettoabsorbtheperfectamount of sunlightneededforlife
Radiation • Electromagneticwaves (thesun´sheatarrives) • Conduction • Directcontact (air touchingwarmland) • Convection • Movement in gases & liquids • Heatalwaysrisesbecauseitislighter/less dense • Whatdoesthismotioncreate? • Themotion of wind and oceancurrents!!!! Howisthermalenergytransferred?
Temperaturedifferences are causedbytheEarth´scurvedsurface Theequatorgets a lot more heatthanthe North and South poles (obvio) ThemotionisalsoaffectedbytheEarth´srotation Movement of air
Tradewinds - Neartheequatorallthewindblowswest and towardtheequator. • Prevailingwesterlies • Oneitherside of thetradewinds, theprevailingwesterliesblowopposite. • Alwaysblowtotheeast (fromthewest) • Alwaysblowawayfromtheequator • Polar easterlies- Polar windsalwaysblowingwest (fromtheeast) and towardstheequator (awayfromthe pole) • See page 352 in textbook Windsystems: Surfacewinds
Jet streamsfollowtheprevailingwesterlies at theirnorth and southborder • Jet streamsaveragebetween 97-185 km/hr • Justlikesailorshaveusedsurfacewindstosailtheirboats, pilots use jet streams • Ifthey are goingeast, theysavegasolinebygoing in the jet stream. • Ifthey are goingwesttheyavoidthe jet streams. Highaltitudewinds: jet streams
Landheats and coolsfasterthanwater!!!! • Duringtheday air abovethelandisheatedbyconduction • Theheated air… • Rises!!!! • So at thebeach in theday, thereis a currentfromthecool sea air going up. • At nightthe air abovelandiscooler • So at thebeach at night, thereis a currentgoingdowntowardsthewater. Dailywinds
Duringthewinter, thelandismuchcolderthantheocean, so likethebeach at night, the air movesawayfromtheland. Duringthesummer, thelandismuchwarmer so thewindblows in fromthe sea. Thiswindisusually full of moisture and brings a lot of rain. Seasonalwinds: monsoon