ClimateChangeResearchInitiative(CCRI)RoundtableI

HowSurfacesAffectAirTemperatures:AStudyofUrbanLandscapesandTheirEffectsonHeat

ElizabethSebastianCCRIEducator- FusionAcademy

AlexGittelsonCCRIGraduateIntern- ColumbiaUniversity

Dr.StuartGaffinCCRINASAMentor

IntroductionsandRoles

Alex“Alexei”GittelsonMPACandidateinEnvironmentalScienceandPolicy,ColumbiaUniversityRole:Research

ElizabethSebastianScienceandMathDepartmentHead,FusionAcademyRole:Educator

Dr.StuartGaffinResearchScientist,NASAGISSandColumbiaUniversityRole:ResearchLeader,Mentor,Advisor

ResearchObjectives

• Howsurfacetemperatureaffectsairtemperature

• Howdifferentsurfacesreflectsunheat– controlledversusoutdoorenvironments

• Whyandhowurbanenvironmentsaregenerallyhotter– roadsversusbuildingsversusnature

• Howcitiesaffectclimatechangeandwhatcanbedone

EducationalObjectives

• Createaunitandpossiblyseveralunitson:– WhatistheUrbanHeatIslandEffect– Howdoesitdirectlyaffectus– Howtocollectdataofsurfaceandabovesurfaceair

temperaturesusingFLIRphoneattachments(experiment;possiblylongterm)

– Howtouseresultstocreatenewdesignstoreduceheatislandeffect

– Explorehowreducingheatislandeffectwillhelpglobally

GeneralConcepts

Air temperature versus surface temperatureUrban Heat Island (UHI) EffectInfrared radiationEmissivityAlbedoGreen/Gray Infrastructure

General Concepts

BigQuestions- StillUnanswered• HowmuchcanwecoolNYCclimatewithmassiveGreenInfrastructure(GI)?(1– 2o C?)

• WhatcombinationofalbedoandGIstrategiesworkbest?• Arethereotherapproaches&newmaterials?• Whataboutpavements?(roofsareonly10-20%urbanhorizontal

surfaces)• Verticalfacades:canwereduceheatinspacesbetweenbuildings(urban

canyonheating)?

Big Questions - Still Unanswered

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Urban Heat Island: GI and Albedo?

Surface Types Measured Over Time

Con Edison Test Site, Gaffin et al, 2010

Rosenzweig et al, 2009

WealreadyknowplentyaboutcommonurbansurfacetemperaturesandhowGIreducesthem

However,weknowmuchlessaboutairtemperaturesabove thesesurfaces.

Experiencewith‘offtheshelf’airtempprobeshasgenerallybeeninconclusive

EventhelargestGI(CentralPark)waschallenging– tookmanyattempts

FLIRthermalinfrared(IR)camerasareextremelypowerfulandprecise:(i)Measureswithin0.1degreesinCelcius orFahrenheit(CLARIFY)

(ii)Eliminatescross-calibrationanddriftissues

(iii)Vastdatacollection

HowtotestAnair tempproxyforcamerawouldbeanimportantmethodologicaladvance.

Candidatesinclude:• Heavyandcopypaper(tested)• Foam(tested)• Metallicfoils(notyettested)

• Measuretemperatureofsurfaces• Determineshortwave(SW)andlongwave(LW)

Proxiesideallyneedtoreflect bothVisible(SW)andIR(LW)backgroundradiation

SW

WhitePaper

LW SW

MetallicFoil?

LW

Whitesheetairtempproxies

FoamCore Heavy

Simple

Copy

FoamCore Heavy

SimpleCopy

KeyCentralParkWeatherStationExperiment

6o Cdropistoomuch

Whythefindingsarestillinconclusive

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Discussion

• Theidealairtempproxyis‘white’inbothvisibleand IRspectrums

• Whitecopypaperisnot‘white’intheIR

• HoweverpapermaybeagoodproxyforhumanthermalcomfortasourbodiesabsorbbackgroundIRaswell

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Going forward

● Metallicfoils(i.e.aluminum)arereflectiveinSWandLWbecauseemissivity islow=>infraredreflectivityhigh

● Needtotestmetallicfoilsnextandmoreonwhitesheets

● ControlledversusOutdoor