geography & climate - | department of zoology at ubcjankowsk/biol413-2-010518...geography &...
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Geography&Climate
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Allspecieshavelimitstotheirdistribu9ons…Toexaminespeciesranges,ithelpstounderstandthephysicaltemplateandclimateThisisfundamentaltobiogeography
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Allbiogeographicpa@ernsareul9matelyinfluencedbythegeographictemplate
Environmentalcondi9onsvaryinahighlynon-randommanneracrossgeographicgradients(e.g.,la9tude,eleva9on,depth,proximitytomajorlandforms–mountains,coastlines)Mostbiogeographicpa@ernsarederivedfromthisveryregularspa9alvaria9oninenvironmentalcondi9ons
Allbiogeographicpa@ernsareul9matelyinfluencedbythegeographictemplate
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(5)Some9mescalledTECOevents–plateTectonics,Eusta9cchangesinsealevel,Climatechange,Orogeny(mountainbuilding)
Figure3.1Lomolinoetal.2010
Climatereflectstemperatureandprecipita9on
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Climateandtectonicchangearethemostimportantlarge-scalefactorsinfluencingspeciesgeneraldistribu9onsHerewe’lllookathowtemperatureandprecipita9onvaryacrossgeographicandregionalscales
FromLomolinoetal.2010
Temperatureandthermalenergy
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Sphericalshapeofearthcausesla9tudinalgradientinthermalradia9on
Figure3.2Lomolinoetal.2010
AngleofincomingradiantenergyaffectsamountofheatabsorbedMostintensehea9ngoccurswhereincomingsunlightisperpendiculartoEarth’ssurface:1) Thegreatestamountofenergyisdeliveredtothesmallestsurfacearea(a<a’)
2) Solarradia9onpassesthroughlessatmosphere;thedistancetraveledthroughtheairisminimized(b<b’)
Temperatureandthermalenergy
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Theangleofinclina9onoftheearth’saxiscausesseasonalitySolarradia7onfallsperpendicularlyondifferentpartsoftheEarthatdifferent7mesofyear
Figure3.3Lomolinoetal.2010
Temperatureandthermalenergy
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Figure3.3Lomolinoetal.2010
Lookingatthefigureontheright,whatdayoftheyearisit?
Theangleofinclina9onoftheearth’saxiscausesseasonalityWhatistheangleandhowdoesthisrelatetotheTropicofCancerandCapricorn?
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Coolingeffectsofeleva9on
Weexaminedla9tudinalvaria9onintemperatureandseasonality...whataboutal9tude?WhydoesMountKilamanjaro,neartheequatorinEastAfrica,havepermanenticeatthetop?Thishastodowiththermalproper9esofair...
Asaclimbergoesupamountainside,thelength(andpressure)ofthecolumnofairabovetheclimberdecreasesWithreducedpressure,airundergoesadiaba%ccooling,aprocesswheregasesloseheatenergyasmoleculesmovefartherapart(andhavefewercollisions)
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columnofairinto
atmosphere
Lowerpressure
Higherpressure
Coolingeffectsofeleva9on
h@p://www.cslctx.org/2012/02/17/the-view-from-the-top/
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WindsandCurrents
h@ps://www.youtube.com/watch?v=dt_XJp77-mkh@ps://www.youtube.com/watch?v=i2mec3vgeaI
CoriolisEffect:thetendencyformovingobjects(e.g.,windandcurrents)toveerclockwise(totheright)intheNHandcounterclockwise(tothelei)intheSH.Weseethiseffectgenerallybetween0°and30°NorthandSouthla9tude
WindsandCurrents
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Differen9alhea9ngwithla9tudedrivesthemajoratmosphericaircircula9on,resul9nginglobalwindpa@erns
Figure3.4Lomolinoetal.2010
1) Equatorisheatedmostintensively.Airattheequatorexpandsasitisheated,becomeslessdensethansurroundingairandrises
2) Risingairreducesatmosphericpressureovertheequatorandsurfaceairnorthandsouthofequatorflowsintoareaofreducedpressure
3) Risingheatedairundergoesadiaba9ccooling,ispushedawayfromtheequator,anddescendsat~30degreesNandSla9tude
WindsandCurrents
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4) Circula9ngairmassesproducesurfacewindsblowingtowardtheequatorbetween0and30degreesandtowardthepolesbetween30and60degrees
5) SurfacewindsdonotblowdueNorSbecauseoftherota9onoftheEarth
Differen9alhea9ngwithla9tudedrivesthemajoratmosphericaircircula9on,resul9nginglobalwindpa@erns
Figure3.4Lomolinoetal.2010
WindsandCurrents
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6) EverypointonEarth’ssurfacemakesonerota9onevery24hours.
7) Pointsathigherla9tudestravelashorterdistancewitheveryrota9on,movingataslowerratethanpointsattheequator
8) ThisinducestheCorioliseffect,wheresurfacewindsaredeflectedtowardtherightintheNHandtotheleiintheSH
Differen9alhea9ngwithla9tudedrivesthemajoratmosphericaircircula9on,resul9nginglobalwindpa@erns
Figure3.4Lomolinoetal.2010
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WindsandCurrentsCoriolisEffect:thetendencyformovingobjects(e.g.,windandcurrents)toveerclockwise(totheright)intheNHandcounterclockwise(tothelei)intheSH.Weseethiseffectgenerallybetween0°and30°NorthandSouthla9tude
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WindsandCurrentsSurfacewindsini9atethemajoroceancurrents(1) Tradewindspushoceancurrentswestwardattheequator(2) Westerliesproduceeastwardcurrentsathighla9tudes(NandS)Thenetresultsarecircularoceancurrents,clockwiseintheNHandcounter-clockwiseintheSH.
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WindsandCurrentsThefivemajoroceancirclingcurrentsarecalledgyres:N.Atlan9c,S.Atlan9c,N.Pacific,S.PacificandIndianOceanGyres.
WindsandCurrents
17Figure3.5Lomolinoetal.2010
Thetemperatureofcurrentsandsurfacewindsaffectstheclimateonland
Geographicprecipita9onpa@erns
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Globaltemperature,winds,andcurrentsinteracttoinfluenceprecipita9on
(FromLomolinoetal.2010)
Partofthishastodowithcloudforma9onandadiaba9ccooling...Asairwarms,itcanabsorbmorewatervaporevaporatedfromlandandwaterWhenaircontainsmoistureandcools,thereisapointatwhichtheairissaturatedwithwatervapor(dewpoint)Furthercoolingresultsincondensa9onandcloudforma9on.Whenwaterandicepar9clesaretooheavytoremainairborne,theyfallasrainandsnow.
Figure3.4Lomolinoetal.2010
Geographicprecipita9onpa@erns
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Tropical rains are heaviest when thesunisdirectlyoverheadandtherateofhea9ngismostintense(thespringandfallequinoxes)
Horse La%tudes: warm, dry surface winds"dry-out" the land and create most of ourgreatdesertsnear30oNandSla9tude(e.g., Mojave, Sonoran, Sahara, Gobi, andGreatSandydeserts)
Figure3.4Lomolinoetal.2010
HorseLa9tudesandadjacentzones
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TwobeltsofdryclimatesencircletheglobeOverland,thesebeltsaretheworld’sdesertsandMediterraneanclimates(mildrainywintersandhotdrysummers)Overoceans,thesebeltshavehotairandli@lewindThetermmaycomefromwhenSpanishshipstransportedhorsestotheWestIndies
h@p://www.rossway.net/horselat.htm
Shipswouldslowinmid-oceaninthisla9tude,prolongingthevoyage...watershortagesforcedcrewstothrowtheirhorsesoverboard
HorseLa9tudesandadjacentzones
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DesertsandMediterraneanclimatesareusuallyontheWesternsideofcon9nentsHere,thelandtemperatureiswarmerthanthecoldocean…coolwesterlywindsofftheoceanwarmwhentheypassoverlandThus,theyabsorblotsofwaterand“drytheland”whentheycomeonshore
Horsela9tudes
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HorseLa9tudesandadjacentzonesTheworld’sdriestdesertsoccurwherewesterliesbringcoldcurrentsandsurfacewinds.Inwinter,thereisli@lerainfallandsummersarehotanddryAtacamaDesert:1mm/year NamibDesert:2-20mm/year
WindsandCurrents
23Figure3.5Lomolinoetal.2010
Thetemperatureofcurrentsandsurfacewindsaffectstheclimateonland
Regionalprecipita9on
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Mountains,inpar9cular,havecomplexeffectsonregionalprecipita9on
Figure3.7Lomolinoetal.2010
Regionalprecipita9on
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Theadiaba%clapserateishowquicklyaircoolsasitrises.Thisratevariesforseveralreasons,butgenerallydifferswithandwithoutcondensa9on.
Figure3.7Lomolinoetal.2010
Regionalprecipita9on
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AircoolsandlosesmoistureasitmovesupthemountainslopeAsitpassesoverthecrestanddescends,itwarmsatahigherrateThiscreatesarainshadoweffectontheleewardsideofmountains
Rainshadoweffect(e.g.,tropicalislandofPuertoRico) Figure3.7Lomolinoetal.2010
Butmountainrangesarenotallthesame…
Mountainsdifferintemperatureandprecipita9onregimesformanyreasons:la9tude,heightandage,tonameafewAsacomparison…considerthesetworanges…
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Whistler,PacificRange,Bri9shColumbia,Canada
GreatSmokyMountains,AppalachianRange,Tennessee-NorthCarolina,USA
Whistlervs.GreatSmokyMountains
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La9tude:51degreesNHighestpeak:4019m(13186i)
Age:60millionyears
La9tude:40degreesNHighestpeak:2037m(6684i)
Age:480millionyears
Whistler,PacificRange,Bri9shColumbia,Canada
GreatSmokyMountains,AppalachianRange,Tennessee-NorthCarolina,USA
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Whistler,PacificRange,Bri9shColumbia,Canada
GreatSmokyMountains,AppalachianRange,Tennessee-NorthCarolina,USA
Whistlervs.GreatSmokyMountains
Thesemountainshavedifferenteffectsonregionalprecipita9onandclimate:oldermountainstendtobesmallerwithsmallerrainshadoweffects.
Climatevaria9on
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ElNinoSouthernOscilla%on(ENSO):periodofweatherchangethatoccursevery2-7yearsduetostrengtheningoftheequatorialcountercurrent(causes9llunderstudy).Increasedrain(oien10x)inaridcoastalregionsofSAwithreducedcoastalupwelling
Seasonalandlong-termvaria9oninprecipita9onare9edtochangesinsolarradia9onandcurrentstrength
Climatevaria9on
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AtacamaDesert
Seasonalandlong-termvaria9oninprecipita9onare9edtochangesinsolarradia9onandcurrentstrengthElNinoSouthernOscilla%on(ENSO):periodofweatherchangethatoccursevery2-7years
duetostrengtheningoftheequatorialcountercurrent(causes9llunderstudy).Increasedrain(oien10x)inaridcoastalregionsofSAwithreducedcoastalupwelling
StrongwarmcurrentpushesmoistureladenairupthecoastsofNandSAmericaResultsinheavyprecipita9oninwinterwhenthelandiscolderthanoffshorewatersTheonly9meitrainsintheextremelyaridcoastaldesertsofSouthAmerica
Climatevaria9on
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GalapagosIslands
Seasonalandlong-termvaria9oninprecipita9onare9edtochangesinsolarradia9onandcurrentstrengthElNinoSouthernOscilla%on(ENSO):periodofweatherchangethatoccursevery2-7years
duetostrengtheningoftheequatorialcountercurrent(causes9llunderstudy).Increasedrain(oien10x)inaridcoastalregionsofSAwithreducedcoastalupwelling
Bringsmorerain(goodforlanddwellers)Warmcurrentreducesupwellingandfood(badformarinelife)
Climatevaria9on
33(FromGrantandGrant2002)
Seasonalandlong-termvaria9oninprecipita9onare9edtochangesinsolarradia9onandcurrentstrength
TheespeciallystrongElNinoin1983increasedfoodavailabilityontheislands,whichalleviatedselec9ononbeakandbodysizeintwofinchspecies
ElNinoSouthernOscilla%on(ENSO):periodofweatherchangethatoccursevery2-7yearsduetostrengtheningoftheequatorialcountercurrent(causes9llunderstudy).Increasedrain(oien10x)inaridcoastalregionsofSAwithreducedcoastalupwelling
Climatechange
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Globalclimatehaschangedfrequently.Climatehasclearlychangedwithcyclesofglacia9on(moreonthislater)
(FromGates1993)
Changesincelastglacialmaxhasnotexceededabout1oCper1000yrs.
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Climatereflectstemperatureandprecipita9on
Thismapshouldbemorefamiliarnow,withanunderstandingofla9tudinalvaria9onintemperatureandwhyweseedesertsandrainforestswherewedo…
ClimateandClimateChangeReferencesforthissec%on:Gates,D.M.1993.ClimateChangeanditsBiologicalConsequences.Sunderland,MA:SinauerAssoc.Grant,P.R.,andB.R.Grant.2002.Unpredictableevolu9onina30-yearstudyofDarwin’sfinches.Science296:707-711.Lomolino,M.V.,B.R.Riddle,R.J.Whi@aker,&J.A.Brown.2010.Biogeography(4thed.,Chapter2).SinauerAssociates,Inc.,Sunderland,Mass.TheCorioliseffectandthedirec9ontoiletsdraininNorthern&SouthernHemispheres:h@ps://www.youtube.com/watch?v=rdGtcZSFRLk
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