Air Temperature Differences in Areas with High-rise Buildings

†

: This study has been supported by CATER 2006-3302 and the authors wish to express their appreciation for the support.

Corresponding author: Kyoo-Seock Lee, Dept. of Landscape Architecture, Sungkyunkwan University, Suwon 440-746, Korea, Tel.:

+82-31-290-7845, E-mail: [email protected]

Air Temperature Differences in Areas with High-rise Buildings ^†

Jin, Wen-Cheng․Lee, Kyoo-Seock

De pt .ofLands c apeAr c hi t e c t ur e ,Sungkyunkwa nUni ve r s i t y

초고층빌딩지역의 기온차

김문성․이규석

성균관대학교 조경학과

국문초록

최근 들어 서울시를 비롯한 대도시에 건립되는 초고층건물은 주변 공기의 대류를 변화시켜 난류현상을 유발하여 빌딩바람과 도시열섬 및 대기오염 물질 집적 등 주변 환경에 영향을 미치고 있다.그 중에서도 고층건물의 주변지역의 기온의 공간적 변화는 환경 경사가 심한 것으로 판단된다.이에 본 연구에서는 서울시 강남구의 초고층건물 지역과 인접 지역의 기온차이를 파악하고자 2 0 0 8 년 3 월 1 6 일부터 2 0 0 9 년 3 월 1 5 일까지 고정관측과 이동관측을 수행하였다.타워팰리스 ( TPL) 와 숙명여고( SMG) 의 거리는 불과 2 00 m이지만 두 관측지점의 연평균 기온차는 0. 7℃로 관측되었고,TPL의 열대야 일수는 13일,SMG는 5 일이었다.TPL의 기온이 다른 곳보다 높은 것은 고층건물에 의한 도로협곡으로 인해 s kyv i e w f a c t o r 가 현저히 낮아 장파복사의 대기 중 방출이 억죄되 도시열섬현상을 가중시키고 냉난방의 단위면적 당 전력 수요가 높아,이로 인한 인공폐열이 도로협곡에 갇혀 고층건물 지역인 TPL의 열섬현상이 인접 지역보다 높은 것으로 관측되었다.

주제어:도시열섬,초고층건물,도시열원

ABSTRACT

I nSe o u l ,s k y s c r a p e r sa r eb u i l ti nc o mme r c i a lz o n e sk n o wna sr e s i d e n t i a l - c o mme r c i a lc o mp l e x e s ,wh i c hc a u s es u c h e n v i r o n me n t a lp r o b l e msa su r b a nh e a ti s l a n d s ( UHI )a n da i rp o l l u t i o n .Toi n v e s t i g a t ea i rt e mp e r a t u r ed i f f e r e n c e si na r e a s n e a rs k y s c r a p e r sa tGa n g n a m- g u ,Se o u l ,So u t hKo r e a ,f i x e da i rt e mp e r a t u r eo b s e r v a t i o na n dt r a v e r s eo b s e r v a t i o n swe r e p e r f o r me df r o m Ma r c h1 6 ,2 0 0 8t oMa r c h1 5 ,2 0 0 9 .Th ea n n u a lme a na i rt e mp e r a t u r ea tTo we rPa l a c e ( TPL)wa sh i g h e r t h a nt h a ta tSo o k my u n gGi r l s ’Hi g hSc h o o l ( SMG)b y0 . 7 ℃,a l t h o u g ht h ed i s t a n c eb e t we e nt h et woo b s e r v a t i o np o s i t i o n s i so n l y2 0 0 m.Th en u mb e ro ft r o p i c a ln i g h t sa tTPLwa s1 3 ,wh i l et h a ta tSMG wa s5 .Th eh i g h e ra i rt e mp e r a t u r ea t TPLwa sd u et oas i g n i f i c a n t l yl o we rs k yv i e wf a c t o r ( SVF) ,wh i c hp r e v e n t e dl o n g - wa v er a d i a t i o nf r o m e mi t t i n gi n t ot h e s k y .Th eh i g h e s ta i rt e mp e r a t u r ei n c r e a s e sn e a rTPLo c c u r r e do ns u mme rn i g h t sb e c a u s eo ft h eh i g h - e l e c t r i c i t yc o n s u mp t i o n v a l u eo f7 0 . 2 2 Wh / m

f o rt h eTPLb l o c ki nAu g u s td u et oa i rc o n d i t i o n i n gf o rc o o l i n g .I ti sc o n c l u d e dt h a tt h ewa r m a i r p o c k e tc e n t e r e do nTPL.

Ke yWo r d s :Ur b a nHe a tI s l a n d ,S k y s c r a p e r s ,Ur b a nWa r m Po c k e t

Ⅰ.I nt r oduc t i on

Be c aus eo fi nc r e as e si nt heur banpo pul at i o nc o nc e nt r at i o n i nSe o ul ,s e ve r als kys c r ape r shavebe e nbui l ti nt hec o mme r c i al z o ne s ,kno wna sr e s i de nt i al - c o mme r c i a lc o mpl e xbui l di ngs ,whi c h c r e at et hee nvi r o nme nt alpr o bl e mso fur banhe ati s l ands (UHI ) andai rpo l l ut antde po s i t i o n.UHIi st hephe no me no ni nwhi c h ur banai rt e mpe r at ur e sar ehi ghe rt hant ho s eo fs ur r o undi ng r ur alar e as .Thi si sduet ot her adi c alc hange si nt hes ur f ac e andat mo s phe r i cpr o pe r t i e so far e gi o n( Mo nt áve z e tal . ,20 00) c aus e dbyc har ac t e r i s t i c sl i kede c r e as e dgr e e ns pac e ,l o wwi nd s pe e d,andt hel o w al be doo fur banl andc o ve rmat e r i al s .The e xt r awar mt hne arc i t i e si sr e l at e dt os e ve r alf ac t o r s :i n- c r e as e dabs o r pt i o no fs ho r t - waver adi at i o n,i nc r e as e ds t o r age o fs e ns i bl ehe at ,ant hr o po ge ni che atpr o duc t i o n,r e duc e dl o ng- wa ver adi a t i o nl o s s e s ,l o we re vapo t r ans pi r a t i o nr a t e s ,andl o we r s e ns i bl ehe atl o s sduet or e duc e dt ur bul e nc ei nur banc anyo ns (Oke ,1 987),ando t he rf ac t o r s ,s uc hass yno pt i cwe at he rc o n- di t i o ns (Oke ,19 88 ),t o po gr aphy( Go l dr e i c h,19 84 ),a ndc i t ymo r - pho l o gyands i z e (Oke ,1973).

Bui l di ngsar es i gni f i c antus e r so fe ne r gy and mat e r i al s . Thus ,e ne r gyc o ns e r vat i o ni nbui l di ngspl aysani mpo r t antr o l e i nur bane nvi r o nme nt als us t ai nabi l i t y.Anur banar e awi t ha hi ghbui l di ngdens i t ycanexper i encepoorvent i l at i onanda s t r o ng“he ati s l and”e f f e c t (Hui ,20 01 ).Bui l di ngma s s e si nc r e a s e

Figure1.Googleearthimageanddigitalmapofstudysite

t het he r malc apac i t yo fanar e a,havi ngadi r e c tbe ar i ngo n c i t y t e mpe r at ur e s .Thehe atabs o r be d dur i ng t heday by bui l di ngs ,r o ads ,ando t he rc o ns t r uc t i o ni nanur banar e ai s r e -e mi t t e daf t e rs uns e t ,c r e at i nghi ght e mpe r at ur edi f f e r e nc e s be t we e nur banandr ur alar e as (Raj ago pal ane tal . ,2008).

Thet he r mali mpac tde r i ve df r o m bui l di ngar r ange me nt sat dayt i meo n t heur ban c ano pyl aye r (UCL)ai rt e mpe r at ur e wasanal yz e dbyShas hua-bar e tal . ( 2004)andGi r i dhar ane t al . (2 004,2005)s ho we dt hatt hes ur f ac eal be do ,SVF,and he i ght -t o -f l o o rar e ar at i owe r et hei mpo r t antvar i abl e sf o r t he r mali mpac tby hi gh r i s ebui l di ngs .Al s os t udi e so fai r t e mpe r at ur ei nc r e as e sc aus e dbys kys c r ape r swhi c hf o c us e d o nSVFhavebe e npe r f o r me d(Yamas hi t a e tal . ,1986;Pi nho andMans oOr gaz ,2 000;Sve ns s o n,2 004;Cho w andRo t h, 2006 ;Ri z wane tal . ,20 08).Ho we ve r ,t he r ehaveno tbe e n many s t udi e st o de t e r mi ne t he e f f e c to fs kys c r ape r so n adj ac e nta r e aai rt e mpe r a t ur ei nc r e a s e ;t he r e f o r e ,i ti sne c e s s a r y t ode t e r mi net het he r mali mpac to ft hene w s kys c r ape r s .

Ⅱ.Mat e r i al sandMe t hods

1 .St udySi t eDes c r i pt i on

Thes t udys i t ei st her e s i de nt i al - c o mme r c i a lc o mpl e xbui l di ng

ar e aatDo go k-do ng,Gangnam-gu,Se o ul ,So ut hKo r e a(Re f e r

t oFi gur e1 ).

Figure2.3DGISmapofthestudysite

Be c a us es i xs kys c r a pe r samo ngt het o p2 5hi gh-r i s ebui l di ngs i nSo ut hKo r e ahavebe e nbui l ti ns i deas i ngl ebl o c k,t hi ss i t e wass e l e c t e df o rt hei nve s t i gat i o n.Thet al l e s tbui l di ngatt he s t udys i t ei sTo we rPal ac eI I I ( TPL),wi t hahe i ghto f2 64m.

Thel e ngt handwi dt ho ft hebl o c kar eabo ut500m and300 m,r e s pe c t i ve l y.Aswec ans e ei nFi gur e1,t hes t udys i t ei s de ns e l ybui l ts kys c r ape rar e awi t hl o w SVF whi c hi nduc e s manymi c r o me t e o r o l o gi c ali mpac t ss uc hasbui l di ngwi ndsand i nc r e as i ngo c c ur r e nc eo ft r o pi c alni ght sandhe atwave .

Mi c r o me t e o r o l o gy,s uc hast hee xt e ntandi nt e ns i t yo ft he ur banhe a ti s l a nd,i sa f f e c t e dbyt o po gr a phy( Lands be r g,198 1).

Wi t hr e gar dt ot hes t udys i t e ,TPL(2 64m hi gh)i so nt he bl o c k,Mt .Mae bo ng(95m hi gh)i sabo ut3 00m t ot heno r t h, Yangj aeSt r e am i sabo ut100 m t ot hes o ut h,andMt .Dae mo (293 m hi gh)andMt .Gur yo ng(283m hi gh)ar eabo ut2km t o t hes o ut h( Re f e rt oFi gur e2).

2 .Obs er v at i onPosi t i onDesc r i pt i on

Fo ro bs e r vat i o npo s i t i o ns ,TPLi st hes kys c r ape rwi t ht he

No. Initial Observationposition Landuse Albedo Elevation(m) a TPL TowerPalace Commercial-residentialcomplex 0.12 17 b HSA HanshinApartment Medium densityresidential 0.17 17 c DBC DongbuCentreville Highdensityresidential 0.17 20 d SMG SookmyungGirls’HighSchool Educational 0.19 17 e YJL YangjaeStream LeftDike Urbanstream 0.25 30 f MBM MaebongMountain Urbanforest 0.25 63 g HJD HanjeonElectricalCo.Dormitory Educational 0.25 30 Table1.Landuseatobservationpositions

l o we s tSVF.Mae bo ngMo unt ai n(MBM)i samo unt ai nf o r e s t , Do ngbuCe nt r e vi l l e (DBC)andHans hi nApar t me nt ( HSA)ar e apar t me nt swi t h24- s t o r y,and9s t o r y,r e s pe c t i ve l y.Yangj ae

Figure3.Landusemapofthestudysite

Legend: :Public :Residential :Green-Openspace :Road :River :Commercial :Bare :Mixed :Commercial-Residential

a:TPL b:HSA c:DBC

d:SMG e:YJL f:MBM g:HJD

Figure4.Photosofobservationpositions

St r e am Le f tDi ke (YJ L)i sas t r e am bank.SMGandHanj e o n El e c t r i c a lCo .Do r mi t o r y( HJ D)i sane duc a t i o nalf a c i l i t yc o ve r e d wi t h gr as sand as phal t ( Re f e rt oFi gur e3 and Tabl e1).

Pho t o so fal lo bs e r vat i o npo s i t i o nsar es ho wni nFi gur e4.

3 .Met hods

1)Fi xe dTe mpe r at ur eObs e r vat i o n

Tode t e r mi net hei nf l ue nc eo fs kys c r ape r so nai rt e mpe- r at ur edi f f e r e nc e s ,ai rt e mpe r at ur eandhumi di t ywe r eo b- s e r ve dbyHi o ki -3641 -20di gi t alt e mpe r at ur e - humi di t y( T-H) s e ns o r si ns t al l e datt hes t udys i t e .Thes e ns o rme as ur e me nt r angewas－20. 0℃ t o70℃,andt heac c ur ac ywas±0. 5℃

( Hi o kiE. E.Co r po r a t i o n,ht t p: / / www. hi o ki . c o m/ pr o duc t / 3 6 4 1 2 0 / i nde x. ht ml ,No ve mbe r2 009).Al lT-Hs e ns o r swe r ec al i br at e d be f o r ei ns t al l at i o nt oe ns ur edat aac c ur ac yandt he nmo unt e d o nt ot hemi ddl epar to fas t r e e tl ampatahe i ghto f2- 2. 5m abo vegr o undt oavo i dr adi at i o ni nve r s i o nandvandal i s m.The me as ur e me nti nt e r valwas10mi nut e s ,andt heo bs e r vat i o n pe r i o dwasMar c h16,20 08t oMar c h15,2009 .Ho we ve r ,TPL dat af r o m 8 /13/11 :00t o9/16/ 13:10,200 8wasno to bs e r ve d duet ovandal i s m and,t hus ,we r eno ti nc l ude di nt heanal ys i s . Thedat af r o m Ga ngna m Aut o ma t i cWe at he r i ngSt a t i o n( GWS)

o fKo r e aMe t e o r o l o gi c alAdmi ni s t r at i o n(KMA)we r eus e dt o Re f e rt owe at he rc o ndi t i o nsdur i ngt heo bs e r vat i o npe r i o d.

2)Tr ave r s eObs e r vat i o n

Tr ave r s eo bs e r vat i o natt hes t udys i t ewaspe r f o r me dt o

de t e r mi net hes pat i ale xt e nto ft heai rt e mpe r at ur ei nc r e as e

ne a rTPL.Thes ameHi o ki - 3 6 4 1 - 2 0s e ns o rwasus e df o rt r a ve r s e

o bs e r vat i o n,andaGar mi nGPSmap60c xr e c e i ve rwasus e dt o

ac c ur at e l y o bs e r vet i meand navi gat i o n.Theme as ur e me nt

i nt e r valwase ve r y2s e c o nds ,andt heo bs e r vat i o nwasc o n-

duc t e d f r o m 21: 30 t o22:45o n De c e mbe r26,2 008.The

maxi mum ai rt e mpe r at ur edi f f e r e nc eo c c ur r e datni ghtwi t h

l i ghtwi ndsandc l e ars ki e s ( El i as s o n,1996) .Fi gur e5i l l us t r at e s

t he29t r ave r s eand f i xe d o bs e r vat i o n po s i t i o nsf o rde t e r -

mi ni ng t hes pat i ale xt e nto ft heai rt e mpe r at ur ei nc r e as e

c aus e dbyTPL.Fo rt hef i xe dme as ur e me nt ,i naddi t i o nt o

t he7o bs e r vat i o npo s i t i o nsme nt i o ne dabo ve ,4f i xe do bs e r -

vat i o npo s i t i o nswe r eadde dasNo . 21(Me e doApt . ),23 (Gae po

Apt .4) ,26 (Gur yo ngVi l l age )and28(Hangnye o ul ).No .21,23

we r eatme di um de ns i t yr e s i de nt i alar e awi t hpave me nto f

c o nc r e t eandas phal t .No .26wasatt hegr as sar e ao ft he

f o o t s l o peo fMt .Gur yo ng.No .28wasatt hepe r i phe r alar e a

o fSs angyo ngApar t mentadj ac e ntt oYangj aeSt r e am.The s e

Figure5.Traverseandfixedmeasurement

Legend: :Traversemeasurement :Fixedmeasurement Education:1,12,15,20,24;Commercial:2,3,4,29;Park:7; Forest:19;Stream:22

Residential:5,6,8,9,10,11,13,14,16,17,18,21,23,25,26,27,28

s t a t i o nsa r er e l a t i ve l yf a ra wa yf r o mTPL.Fo re xa mpl e ,Gur yo ng vi l l age (No .2 6)s t at i o ni sl o c at e df arapar tal mo s t2km.Thus , t hedat af r o m t he s e4o bs e r vat i o ns t at i o nswe r eno tus e df o r i nve s t i gat i ng t hee f f e c to fs kys c r ape r so n ai rt e mpe r at ur e di f f e r e nc e s .

3)Dat aAnal ys i s

El e vat i o nc al i br at i o nwasdo neo nl yf o rMBM dat abe c aus e al ls t at i o nse xc e ptMBM ar el o c at e dats i mi l arhe i ght (Re f e r t o Ta bl e 1 ).I n o r de rt o i nve s t i ga t e t he ai rt e mpe r at ur e di f f e r e nc e samo ng o bs e r vat i o n po s i t i o ns ,we at he rdat at hat we r eo bs e r ve do nr ai nydayso rwi t hs pe e dso fo ve r3. 4m/s e c o rwi t hc l o udc o ve rval ueo ft hr e eo rmo r ewe r ee xc l ude d f r o m t he anal ys i s be c aus e s i gni f i c antt he r maldi f f e r e nc e s c anno tde ve l o pi nt he s ewe a t he rc o ndi t i o ns .Themaxi mum, mi ni mum,anda nnua lme a na i rt e mpe r a t ur e sa ta l lo bs e r va t i o n po s i t i o nswe r ee xa mi ne d f i r s t .The n,t hedi ur nalvar i at i o ns t hr o ugho ut t he ye ar we r e s ho wn t o i l l us t r at e t he ai r t e mpe r at ur ec hange s .Ne xt ,t heai rt e mpe r at ur edi f f e r e nc e be t we e nt heTPL andSMG l o c at i o ns ,andt henumbe r so f t r o pi c alni ght satt hes t udys i t ewe r ede t e r mi ne d.Theannual me anai rt e mpe r at ur eandc o o l i ngde gr e edays (CDD)f o ral l o bs e r vat i o n po s i t i o nswe r ede r i ve d i n t e r mso fl and c o ve r c har ac t e r i s t i c s . Af t e r r e vi e wi ng t he annual me an ai r t e mpe r at ur e s and CDD f o r al lo bs e r vat i o n po s i t i o ns ,t he

ne ar e s tSMG wass e l e c t e d and c o mpa r e d wi t h TPL t o de t er mi net heai rt emper at ur ei ncr eas eef f ectofTPL.

Ai rt e mpe r at ur edat awe r eanal yz e di nt e r mso fs e as o nal var i at i o n.Se as o nalvar i at i o nswe r et e s t e d t ode t e r mi neai r t e mpe r at ur ee f f e c t s .Thes e as o nswe r ec l as s i f i e di nt os pr i ng ( Ma r c h- Ma y) ,s umme r ( J une - Augus t ) ,f a l l ( Se pt e mbe r - No ve mbe r ) , andwi nt e r (De c e mbe r -Fe br uar y).Tode t e r mi net hedayt i me ai rt e mpe r at ur ei nc r e as e ,t hedat aat14:40wasus e dbe c aus e i nc o mi ngs o l are ne r gyatt hi st i mes t i l le xc e e dst heo ut go i ng he ate ne r gyf r o m t hes ur f ac e ,e ve nt ho ughi tde c r e as e si n i nt e ns i t y af t e rno o n( Ahr e ns ,2 008).Thedat at ake n t hr e e ho ur saf t e rs uns e twasus e df o rni ght t i medat a.Thus ,ni ght - t i mede pe nde do nt het i meo fs uns e t .

Thes pat i ale xt e nto ft het he r mali nf l ue nc eo ft hes ky- s c r ape r swasde t e r mi ne d us i ng an e as tt owe s tho r i z o nt al pr o f i l e ,andano r t ht os o ut hho r i z o nt alpr o f i l e .

The ant hr o po ge ni che atwase s t i mat e d us i ng e l e c t r i c i t y c o ns umpt i o ndat af o rt heTPL,SMG,andHSA bl o c ks .The n, t heannual ,mo nt hl y,ands e as o nalant hr o po ge ni che atf l uxe s f o rt het hr e ear e aswe r ee xami ne d.

Ⅲ.Re s ul t s

1 .TheMax i mum andMi ni mum Ai rTemper at ur es

Themaxi mum ai rt e mpe r at ur edur i ngt heo bs e r va t i o npe r i o d was36. 0℃,ando c c ur r e dat15: 30o nAugus t8,2008atYJ L.

Themi ni mum val uewas－12. 0℃ ando c c ur r e dat7:40,7: 50, and8:10o nDe c e mbe r6,200 8,atMBM.

Month Numbersofdays

January 17

February 8

March 10

April 9

May 10

June 1

July 1

August 4

September 3

October 13

November 9

December 8

Total 93

Table2.Numberofdaysfittingtheweatherconditions

We at he rdat af r o m r ai nydays ,dayswi t hac l o udc o ve r val ueo f3o rmo r e ,o rwi t hwi nds pe e dso fo ve r3. 4m/swe r e e xc l ude d.Thenumbe ro fdaysmat c hi ngt heabo vec o ndi t i o ns i ss ho wni nTabl e2.

Thedi ur nalvar i at i o nsi nai rt e mpe r at ur eatt hes e ve no b- s e r va t i o npo s i t i o nsf o ro neye arwe r ec o mpar e d(Re f e rt oFi gur e 6).Themaxi mum ai rt e mpe r a t ur eo f1 3. 5℃ wa so bs e r ve dat YJ L(14:5 0)andt hemi ni mum ai rt e mpe r at ur eo f3. 3℃ was al s oo bs e r ve da tYJ L( 0 6 : 2 0 ) .Theda i l yme a nmi ni mum t e m- pe r a t ur ewaso bs e r ve di mme di a t e l ybe f o r es unr i s e ,a ndt hedai l y me anmaxi mum t e mpe r at ur ewaso bs e r ve datmi d- af t e r no o n.

Thehi ghe s tme anai rt e mpe r at ur eo f9. 3℃ waso bs e r ve dat TPLf o l l o we dbyDBC( 9 . 2 ℃) ,HSA(8 . 9 ℃),SMG( 8 . 6 ℃) ,MBM (8. 2℃),HJ D( 8. 1℃)andYJ L(8℃)(Re f e rt oTabl e3).Eve n i ft he yHSA andSMG ar el o c at e do nl y410m and200m f r o m TPL,t heai rt e mpe r at ur edi f f e r e nc ewi t hTPLi s0. 4℃

and0. 7℃,r e s pe c t i ve l y.Theme anai rt e mpe r at ur eatMBM was l o we r t han t hat at TPL be c aus e t he l and us e c l as s i f i c at i o ni sur banf o r e s te ve nt ho ughi ti sl o c at e datt he CBDar e a.Theai rt e mpe r at ur eatHJ Dwasaf f e c t e dbyc o o l ai rf r o m Mt .Dae moandMt .Gur yo ng,s oi twa sc o o l e rt han t ha ta tTPL.The r e f o r e ,

Figure6.Diurnalvariation ofairtemperatureatallobservation positionsforoneyear

Legend: :MBM :HSA :TPL :YJL :SMG :DBC :HJD

TPL DBC HSA SMG MBM HJD YJL

Ave. 9.3 9.2 8.9 8.6 8.2 8.1 8

Max. 13.4 13.1 13.4 13.1 12.8 13.2 13.5

Min. 5.5 5.7 5 4.8 4.4 3.9 3.3

Table3.Theaveragetemperature,maximum temperatureandminimum temperatureforoneyear(Unit:℃)

awar m po c ke tf o r me dar o undTPL whe r et hes kys c r ape r s ar el o c at e d.

2 .Ai rTemper at ur eDi f f er enc ebet weenTPLandSMG

Tode t e r mi net heai rt e mpe r at ur ei nc r e as ene arTPL,t he di f f e r e nc ei nai rt e mpe r at ur ebe t we e nTPL andSMG was anal yz e dbe c aus eSMGi so nl y20 0m f r o m TPL.Themaxi - mum a i rt e mpe r a t ur edi f f e r e nc ebe t we e nTPLa ndSMG,4 . 8 ℃, waso bs e r ve dat2 0:40o nDe c e mbe r3,2008.Thes yno pt i c we at he rc o ndi t i o nsatGWSatt hi st i mes ho we dnopr e c i pi - t at i o n,ac l o udc o ve r ager at i oo f2. 9,andawi nds pe e do f1. 4 m/s e c .Hi ghpr e s s ur ec o ve r e dt heKo r e anPe ni ns ul a,andt he pr e s s ur egr adi e ntwasge nt l e ,s ot hewe at he rwasc l e arand c al m att hatt i meac c o r di ngt ot hes yno pt i cwe at he rmap.

Themi ni mum ai rt e mpe r at ur edi f f e r e nc e ,abo ut-3. 1℃,was o bs e r ve dat4:20o nJ anuar y30,2009.Thes yno pt i cwe at he r c o ndi t i o nsatGWS att hes amet i meal s os ho we dnopr e- c i pi t at i o n,ac l o udc o ve r ager at i oo f2. 9,andawi nds pe e do f 1. 0 m/s e c .Ac c o r di ngt ot hes yno pt i cwe at he rma p,l o wpr e s s ur e pe r vade dt heKo r e an Pe ni ns ul a,and t hepr e s s ur egr adi e nt wass t e e p.

Theannualme anai rt e mpe r at ur edi f f e r e nc ebe t we e nTPL andSMG,o nl y2 00m apar t ,was0. 7℃,ho we ve r ,t hedi s t anc e be t we e nt het woo bs e r vat i o npo s i t i o nsi so nl yabo ut200m.

Thema xi muma i rt e mpe r a t ur edi f f e r e nc edur i ngdi ur na lva r i a t i o n, 1. 4℃,waso bs e r ve dat21: 10,whi l et hemi ni mum ai rt e m- pe r at ur edi f f e r e nc e ,0. 1℃,waso bs e r ve dbe t we e n12 :40 (Re f e r t oTabl e4,Fi gur e7).Thi sf i ndi ngpr o ve st hatas i gni f i c ant ai rt e mpe r a t ur edi f f e r e nc eo c c ur r e datni ght .Be c aus et hel o we r al be doo fmanyur banmat e r i al sr e s ul t si ngr e at e rabs o r pt i o n o fs o l arr adi at i o ndur i ngt hedayt i me ,andt hes t o r e de ne r gy e mi t sl o ng-waver adi at i o natni ght ,t heSVFatTPLwasas

Ave.(℃) Max.(℃) Min.(℃)

Δ

(21:10)

0.1 (12:40) Table4.AirtemperaturedifferencebetweenTPLandSMG during

diurnalvariation

Figure7.Diurnalvariationinairtemperaturedifferencebetween TPLandSMG

Legend: :TPL :SMG :TPL-SMG

l o w as0. 15whi c hbl o c ksl o ng-wavee mi s s i o n,s uc ht hatt he maxi mum ai rt e mpe r at ur edi f f e r e nc eo c c ur r e datni ght .

3 .TheTr opi c alNi ght sandCool i ngDegr eeDay sat t heSt udySi t e

A t we nt y-f o urho urpe r i o dwi t hami ni mum ai rt e mpe r a- t ur eabo ve25℃ i sc al l e dat r o pi c alni ght ,ac c o r di ngt ot he Ko r e aMe t e o r o l o gi c a lAdmi ni s t r a t i o n( ht t p: / / we b. kma . go . kr / no t i f y/

pr e s s /kma_l i s t . j s p?bi d=pr e s s &mo de =vi e w&num=1191120).

Fi gur e8s ho wst henumbe ro ft r o pi c alni ght satal lo bs e r - vat i o npo s i t i o ns .TPLhadt hehi ghe s tnumbe rat1 3,f o l l o we d byDBC(11),HSA( 9),SMG(5) ,MBM(3),HJ D(2),andYJ L

Figure8.Thenumberoftropicalnightsateachobservationposition Legend: :Commercial-Residential :Residential

:Education :Green-Openspace

Figure9.CDDforallobservationpositions

Legend: :Commercial-Residential :Residential :Education :Green-Openspace

(1).Thi sf i ndi ngpr o ve st hatt heur banmi c r o c l i mat eo fTPL hasc har ac t e r i s t i c ss i mi l art ot ho s eo fCBD,e ve nt ho ughTPL i ss ur r o unde dbyr e s i de nt i alar e asandanur bans t r e am(YJ L).

Thel andus ede s i gnat i o no fTPLi sr e s i de nt i al -c o mme r c i al , and TPL i sl o c at e dathi gh-r i s ebui l di ngbl o c k;t he r e f o r e , mo r eant hr o po ge ni che ati sr e l e as e datTPL t hanato t he r o bs e r vat i o npo s i t i o ns .I naddi t i o n,t hel andc o ve ratTPL i s as phal tandc o nc r e t ewi t hanSVFo f0 . 1 5.Thus ,t hegr o und s ur f ac emai nl yabs o r be dt hes o l are ne r gydur i ngt hedayt i me and e mi t t e d l o ng-wave r adi at i o n atni ght .Ho we ve r ,t he l o ng-waver adi at i o nc o ul dno tber e l e as e ddi r e c t l yi nt ot he at mo s phe r e ,butr at he rr e mai ne di nt heSC duet ot hel o w SVF,r e s ul t i ng i n ahi ghe rai rt e mpe r at ur et han ato t he r o bs e r vat i o npo s i t i o ns .

Thec o o l i ngde gr e edays (CDD)atal lo bs e r vat i o npo s i t i o ns we r ec al c ul at e d.Themaxi mum CDD,677. 4,o c c ur r e datTPL, f o l l o we d by SMG(6 28. 5),DBC(617. 35) ,HSA(598. 15) ,HJ D (571 . 8 ),MBM(541. 75 ),andYJ L(533. 05) (Re f e rt oFi gur e9).

4 .SeasonalAi rTemper at ur eI nc r eas enearTPL

Af t e re xc l udi ngt hedayswi t hwe at he rc o ndi t i o nsaf f e c t i ng f r e ec o nve c t i o n, (pr e c i pi t at i o n,c l o udc o ve r≥ 3,wi nds pe e d≥

3 . 4m/ s e c ) ,t heme a n,maxi mum,a ndmi ni mum a i rt e mpe r a t ur e di f f e r e nc e sbe t we e n TPL and SMG i n t e r mso fs e as o nal var i at i o nwe r ede r i ve d.Thehi ghe s tai rt e mpe r at ur edi f f e r e nc e o f1℃ be t we e nTPL andSMG o c c ur r e di nf al l ,f o l l o we dby wi nt e r ( 0. 7℃),ands pr i ngands umme r (0. 4℃).

Thedi ur nalvar i at i o ni nai rt e mpe r at ur edi f f e r e nc ebe t we e n

t het woo bs e r vat i o npo s i t i o nswasal s oc o mpar e dbys e as o n.

The r ewasas i mi l ara br uptai rt e mpe r at ur ede c r e as eo ns pr i ng and s umme rmo r ni ngs ,wi t h s umme rs ho wi ng t hel ar ge s t de c r e as e at1 1:20.TPL i sl o c at e d be t we e n s kys c r ape r s ; t he r e f o r e ,dur i ngt hedayt i me ,t hes o l are ne r gyc anno tr e ac h t her adi at i o ns hi e l di nt hes t r e e tc anyo n(SC)di r e c t l y.SMGi s l o c at e dbe s i deat hr e e -s t o r ys c ho o lbui l di ng,al l o wi ngs unl i ght t or e ac ht her adi at i o ns hi e l d,s uc ht hatt heai rt e mpe r at ur e washi ghe rt hant hatatTPL dur i ngt heday.Dur i ngt he ni ght ,ho we ve r ,t hehi ghe s tno c t ur nalc o o l i ngo c c ur r e ddur i ng t hes umme r ,andt hemaxi mum ai rt e mpe r at ur edi f f e r e nc eo f 2℃ o c c ur r e dat21:00( Re f e rt oFi gur e10).

Toi nve s t i gat et heno c t ur nalc o o l i ngbe t we e ns e as o ns ,t he c o o l i ngr at e (CR)be t we e nt heai rt e mpe r at ur eats uns e tand t hr e eho ur saf t e rs uns e tf o ral lo bs e r vat i o n po s i t i o nswas c al c ul at e d.Thes e as o nalc o o l i ngr at ef o ral lo bs e r vat i o npo s i - t i o nsi ss ho wni nFi gur e11.I twasmo s ts i gni f i c anti ns pr i ng, wi t ht hehi ghe s tCR o c c ur r i ngatHJ D andt hel o we s tat DBC.I n s pr i ng,t hedayt i meai rt e mpe r at ur ei nc r e as e sby i ncr eas i ngs ol arr adi at i on,however ,t hel ands ur f acei ss t i l l

Figure10.SeasonalairtemperaturedifferencebetweenTPLand SMG

Legend: :Spring :Summer :Fall :Winter

Time Night-time Daytime

Season Spring Summer Fall Winter Spring Summer Fall Winter Clear

<3 * * *

Δ

Δ

Calm

<3.4m/s * * * * - - * *

*Statisticallysignificant;

Δ

Table6.AirtemperaturedifferencesbetweenTPLandSMGatstableweatherconditions

Figure11.SeasonalCRforallobservationpositions

Legend: :Spring :Summer :Fall :Winter

c o o ldo wnbyl o w s o l arr adi at i o ndur i ngwi nt e r .Thus ,t heai r t e mpe r at ur ego e sdo wnr api dl yaf t e rs uns e t .

The t -t e s tr e s ul to ft heai rt e mpe r at ur edi f f e r e nc ebe t we e n TPL andSMG f o ral ls e as o nsi ss ho wni nTabl e5.Wi nt e r s ho we dt hemo s ts t at i s t i c al l ys i gni f i c antr e s ul t .

Theai rt e mpe r at ur edi f f e r e nc ebe t we e nTPL andSMG dur i ngdayt i meandni ght -t i mei ne ac hs e as o nwasal s ot e s t e d us i ngt hemat c he dpai rt wo -t ai l e dt -t e s twi t has i gni f i c anc e l e ve lo f0. 05.Themo s ts t at i s t i c al l ys i gni f i c antr e s ul t so c c ur r e d atni ghtwi t hc l e arandc al m we at he rc o ndi t i o nsi ns pr i ng, s umme r ,andf al l ,andal s odur i ngt hedaywi t hc l e arand c al m we at he rc o ndi t i o nsi nf al landwi nt e r .Ther e s ul t so ft he t -t e s tf o rs t abl ewe at he rc o ndi t i o nsar es ho wni nTabl e6, whe r et hel abe l‘ ∆'i ndi c at e swhe r et henumbe ro fs ampl e s wasno te no ught obet e s t e ds t at i s t i c al l y.

Season Spring Summer Fall Winter Statistical * * * *

*Statisticallysignificant

Table5.Thestatistical

t

5 .Spat i alEx t ento fAi rTemper at u r eI nc r eas i ngEf f ec t s Duet oTPL

A t r ave r s eo bs e r vat i o nwasmadet ode t e r mi net hes pat i al e xt e nto ft het he r mali nf l ue nc eo ft hes kys c r ape r s .Theo b- s e r vat i o nwasc o nduc t e df r o m 21 :30t o2 2:45o nDe c e mbe r 26,2008,s uc ht hatc al i br at i ngt heai rt e mpe r at ur edat abas e d o n t hes t andar dt i mewasne c e s s ar y.Theai rt e mpe r at ur e dat aats e ve r alf i xe do bs e r vat i o npo s i t i o nswe r eal s oc o mpar e d wi t ht het r a ve r s eo bs e r va t i o ns .Themaxi mum ai rt e mpe r at ur e was－2 . 2 ℃,o bs e r ve datTPL,andt het e mpe r at ur eatt he ne ar byr e s i de nt i alar e awasl o we rby0. 3℃ t o0. 7℃.

I nt hewe s tt oe as tho r i z o nt alpr o f i l e ,t heai rt e mpe r at ur eat HSA wa s－3. 2 ℃ andi nc r e as e di mme di at e l yatTPL( －2. 2 ℃), t he nde c r e as e ds l o wl yt o war dt heo bs e r vat i o npo s i t i o nne ar t heYangj aeSt r e am t o－3. 2℃.Thi sf i ndi ngi ndi c at e st hat TPLc aus e dawar mi ngpo c ke te f f e c tatt hes t udys i t e (Re f e r t oFi gur e12) .

I nt heno r t ht os o ut hho r i z o nt alpr o f i l e ,t heai rt e mpe r at ur e a tMBM wa s－3 . 7 ℃ andi nc r e a s e dt o－3 . 4 ℃ a tSMG,i nc r e a s e d s har pl y t o－2. 2℃ atTPL,t he n de c r e as e d t o－4. 2℃ at Tr ave r s e Obs e r vat i o n Po s i t i o n 2,whi c h wast he Yangj ae s t r e ams i der o adadj ac e ntt ot hebank.Theai rt e mpe r at ur e i nc r e as e dagai nt o－3. 7℃ atObs e r vat i o nPo s i t i o n1 8,and de c r e a s e dt o－5 ℃,－5 . 3 ℃,a nd－6 . 6 ℃ a tObs e r va t i o nPo s i t i o ns 15 (Gae poMi ddl eSc ho o l ),16( t hec o r ne ro fJ ugo ng Apar t - me nt1adj ac entt oYangj aeRo ad),and26(Gur yo ngVi l l age )

Figure12.Westtoeasthorizontaltemperaturedistribution

Figure13.NorthtoSouthhorizontaltemperaturedistribution

(Re f e rt oFi gur e13).Thi sr api dai rt e mpe r at ur edr o pi ns ho r t di s t anc ei sduet ot heKat abat i cwi ndf r o m Mt .Dae moand Mt .Gur yo ng.

Thi sdat ar eveal st hatt het emper at ur eats kys cr aper s , s uchasTPL,i shi ghe rt hani nne ar byar e asandi smuc h hi ghe rt hant e mpe r a t ur e sne armo unt ai nsands t r e ams .Mo un- t ai nsand s t r e amscan ef f ect i vel y r educ e UHI ,butt he s kys c r ape r satTPLpr e ve nt e dt hec o o lmo unt ai nai ratMBM f r o m di s pe r s i ngt ot hes ur r o undi ngar e a.Di f f e r i ngur banl and us ec aus e dai rt e mpe r at ur edi f f e r e nc e sac r o s st heo bs e r vat i o n ar e a,andt het e mpe r at ur ei nc r e as eduet oTPLwass i gni f i - c ant .

Ⅳ.Di s cus s i on

1 .Ai rTemper at ur eI nc r easeDuet oSky s c r aper s

Theannualme an ai rt e mpe r at ur eatTPL was13. 3℃, whi c h was0. 7℃ hi ghe rt han atSMG,e ve n t ho ugh t he di s t anc ef r o m TPLt oSMG i so nl y200 m.Eve ni nt hes ame r e s i de nt i alar e a,TPL was0. 5℃ hi ghe rt hanHSA wi t h a ni ne -s t o r yapar t me ntbui l di ng.Thenumbe ro ft r o pi c alni ght s att heo bs e r vat i o npo s i t i o nswas13atTPL,f o l l o we dby11at DBC,9atHSA,5atSMG,3atMBM,2atHJ D,and1at YJ L.

Thel andandat mo s phe r ear eaf f e c t e dbys o l arr adi at i o n.

Ac c o r di ngt oOke ( 1987),t hes ur f ac ee ne r gybal anc ee quat i o n

i s

Q*+ Q

= Q

+ Q

+ ΔQ

whe r eQ*i st hene tr adi at i o n,

Q

i st heant hr o po ge ni che atr e l e as e ,

Q

i st hes e ns i bl ehe a tt r a ns f e rbe t we e nt hea t mo s phe r e andt hegr o und,

Q

i st hel a t e nthe a tbye va po r a t i o no rc o nde ns a t i o n,a nd ΔQ

i st hehe atf l uxi nt oando uto ft hegr o undo r

o t he rs ur f ac e s .

2 .St r eetCany onandLow SkyVi ew Fac t or

TPL i san SC ar e awi t h al o w al be doandSVF.The al be do so fmat e r i al si nbui l di ngandr o ads ,s uc hasc o nc r e t e andas phal t ,ar el o w.Thus ,mo s ts o l are ne r gyi sabs o r be dby bui l di ngs ur f ac e sandr o adsdur i ngt heday.I naddi t i o n,t he r e i sl i t t l eve ge t at i o n,e xc e ptf o rt r e e sal o ngt hes t r e e t s .SoQ

i s t hepr i nc i pale l e me ntf r o m SC,andΔQ

i sl ar ge ,whi l eQ

i s ne gl i gi bl e (Oke ,1987) .TheSC ge o me t r y att hes t udy s i t e i mpe de dt her e l e as eo fl o ngwaver adi at i o ni nt ot heat mo s phe r e duet ode ns ei nf r as t r uc t ur ewi t hanSVFatTPLasl o w as 0. 15(Re f e rt oFi gur e14).Asar e s ul t ,t hel o ng-waver adi at i o n di dno te mi tt ot heo pe ns kyatni ght ,andt hee mi t t e dhe at wast r appe di nt heSC,whi c hmadet heTPLai rt e mpe r at ur e hi ghe rt ha nt hatatt heo t he ro bs e r vat i o npo s i t i o ns .I na ddi t i o n, t heant hr o po ge ni che atatTPL wasmuc hl ar ge rt hanat SMG andt heo t he ro bs e r vat i o npo s i t i o ns ,i ndi c at i ngt hatt he e xi s t e nc eo fs e ve r als kys c r ape r si no nebl o c kf o r msanur ban war m po c ke t .

Figure14.SVFatTPL SVF(

Ψ

β

3 .TheAnt hr opogeni cHeatEmi ss i onofSky sc r aper s

Ant hr o po ge ni che ate mi s s i o ni samaj o rc aus eo fur banhe at i s l a nds .He atf l uxa s s e s s me nt sha vebe e nunde r t ake nf o rmany c i t i e si ndi f f e r e ntc l i mat i cz o ne s ,butar edi f f i c ul tt oc o mpar e be c aus e o fdi f f e r e nc e si n me t ho do l o gy.Themo s tge ne r al e s t i mat e so fant hr o po ge ni che atf l uxc anbeo bt ai ne df r o m f ue lc o ns umpt i o ni nanadmi ni s t r at i vear e a(Kl ys i k,199 6).I n t hi ss t udy,e l e c t r i c i t yc o ns umpt i o nwasus e dasani ndi c at o ro f ant hr o po ge ni che ate mi s s i o n.

Theant hr o po ge ni che atf r o m e l e c t r i c i t yc o ns umpt i o nwas o bt ai ne df r o m dat at ake nbe t we e nMay2008andApr i l20 09 att heTPL,SMG,and HSA bl o c ks .Thear e aso fTPL, SMG,andHSA we r e52, 31 1. 1m

,33, 70 1. 02m

,and36 , 2 39. 49 m

,r e s pe c t i ve l y,andt het o t alannuale l e c t r i c i t yc o ns umpt i o n was3. 53*10

Wh,1. 07*10

Wh,and2. 55* 10

Wh,r e s pe c t i ve l y.

Thus ,t heannua la nt hr o po ge ni che atf l uxe sf o rt het hr e ea r e as we r e6 74 . 81 Wh/m

,31 . 75 Wh/ m

,a nd70 . 37 Wh/ m

r e s pe c t i ve l y.

Themo nt hl yhi ghe s tval ueo f70 . 2 2Wh/ m

att heTPL bl o c ko c c ur r e di nAugus t ,whi l et ho s eo fSMGandHSA we r e 2. 17Wh/m

and6 . 4 7Wh/ m

,r e s pe c t i ve l y,Thus ,t heai rc o ndi - t i o ni ngus e df o rc o o l i ngatTPL dur i ngt hes umme r (1 90. 94 W/m

)r e qui r e dc o ns i de r abl ymo r ee l e c t r i c i t ype runi tar e a t han t heai rc o ndi t i o ni ng att heo t he rs i t e s (6. 54Wh/m

at SMG,18. 12Wh/m

atHSA) ,duet ot hes i gni f i c anthe i ghto f t hebui l di ngs (Re f e rt oTa bl e7).Thus ,ne arhi ghr i s ebui l di ngs , t hehi ghe s tant hr o po ge ni che atf l ux val ueo c c ur r e d i n t he s umme r ,whi l et hehi ghe s te l e c t r i c i t yc o ns umpt i o no f10. 78 Wh/ m

atSMGo c c ur r e di nt hewi nt e rf o rhe at i ng.I nAugus t , t hes t ude nt satSMG we r eo nvac at i o n.

Al t ho ughHSAi si nar e s i de nt i a la r e al i keTPL,t hee l e c t r i c i t y c o ns umpt i o natt ha tl o c at i o nwasmuc h l e s s ,andt hec o n- s umpt i o nval ue si ns umme randwi nt e rwe r es i mi l ar .I tc anbe c o nc l ude d t hatt heant hr o po ge ni che ati n t hear e ao ft he s kys c r ape rwasgr e at e rt hanatt heo t he rs i t e sbas e do nt he

Season TPL SMG HSA Spring 152.82 7.73 17.24 Summer 190.94 6.54 18.12 Fall 162.23 6.64 16.76 Winter 169.30 10.78 18.33 Annual 675.29 31.70 70.44 Table7.SeasonalelectricityconsumptionatTPL,SMG andHSA

block(Wh/m²)