Seasonal
cyclevariationson the supercontinentof Pangaea
ThomasJ. Crowley
Arcuello
Drive,
Texas77840
Apphed
Research
College
Station.
Corporalion.305
WilliamT. Hyde
TexasA&lviUniversily,
Co egeSlaiion,Texas77843
Clirnale
SyslemFesea.chP.ogramDeparlment
ol t\,4eleofology.
David A. Shod
forAlmospheres,
NASA/Goddard
Maryland
20771
Laboratory
SpaceFlighlCenler,Greenoell.
'
ABSTRACA .
The s.so.rl cycle of tmp€ntuG o! Prngr@ (erny lrle PenEir confgDtio)
b
simuhred with r two-ditne6iotral ene.gt-b.hnce clim.te |nod€|. R..ulls indicrio lh2l ahc
rnrurl m8. of r€dp..rlu6 in lhc Southem H.oirplF.e of Pine.e. wa condd.rrbty hrg.r
lhan .ny o.cuning rt presc.t. M|tinun nprn nodlhly $nn€r l€oper{ut . rE 38 oq
d.yrime highs prcbtbly exceed45 oC ir son€ regions. Horveyer, sumrer ldnp€nlures In
pohr .lgiotrs rf cotrsid€nblylower (0-5 "C) ud .r€ trvonble for p€rdslenc.of tcc ln €a.lem
Arnrdia and glrcidtun in Siberi.---tonditiorll rh.t |@ive.om spfo.r ttm tcobgh dra.Thesesinulatlons suggesllh{ very high sulllt|cr lsry.rrturE rd. hrg. lrnu.l.mge rtc
mijor fealuresof supercofltinenlenvlronment!. Such condlllons my hrve sisnilhrndy influencedrhe disrrlburior o, !.rrestrid Pcn fl biot . Oo. rc$lts m difficdr to i€colrcil€ wilh
postubled '€qrrHe" climd.. fo. sotrF epcttdtiMl
@figm.i(E
INTRODUCTION
tivily of osponseto ah€r€dbou.dary conditionj
The sso.d cycleot temperaturEon Eadh (Crowley€r al.. 1986iHydeet al., 1989)-Tlc
is nrcnsly afiec€d by the land-sa distdbution lavoBble r6poE rpparcntly rellcct' the facr
(e.9.,WsulceandHobbs.1977,Fi8.?.20).P6t thatin contin€ntalinterioF
of thc
rheamplitude
changB in thc land-s disrribulionshould annualtempcralurecyclc is almostlinsrly rcthereforehavesiSnili()antlyalTect€d
thes€$onal ht€dto slar forcins(Crowley.1988).
cycl€. Experinenbwith a wnal
clinaa
For our erperiment.we adoptedthe land-s€.
nod€l{ cro*ley etal.,| 986)suggesr
rharduri.g dhribution lor the ea y LatePernim (Karrnthe pai 100m.y. therewerelaryechang6in ia'l. 260 250 Ma) a firsl mapp€dby Zi€gleret
*aonalny in somereSions(harnow hlve pe. al. ( 1979)md modifi€dby ScoG. ( 1986).B.manen(icecolcl (G@nlard and A.i!rcde). crN differentrecodtructionsof Pangrezhrvc
(cf. Liv€rmore
eral., 1986),out
Fudherexpcdmenh
for thcCondwanan
sup€F b€enpropos€d
(crc*le! eral-.1987)indicllcmajol erp€ menlsshouldbeconsidercda {i|sl att€mpl
contiflenr
chantg in suFncr tenFolured th.landmN ro $s€sss€$onalcycl€vlrirtios oi the soFr
noved ovc. rhe SouthPole.In tht pap€rwe condnenrandmnduioff ac subjectto modiliexplore!€enal cycleveriations
of reinpcrarnie cldon tor ahematecontinerlal configuodoff.
for thc mo$ exrcmecaseof land-seaconfigua' We haveaho not includ€dtopoglphic ero.rs in
don. Pangaea.Bccau5ethc land na$ ws5c.n- ft. model. Allhough rhc latter clled may b.
md Hay. l98l), thefitstter€din lo* ard middl€latitud€s,
our p mlry impo.tant(Southam
focusL onchangcs
in thde rcSions.although
we oder trend tor the pres€ntclimare is nost
nrke sne conhe s rbour @ndiiions itr st.ongly lll€€ted by the l.nd{€a disribulion
(wdlac€ and Hobb6.1977.Fis. 7.20).Wc
thcrefo.erhink it 's apprcpdateto first focut on
MODEL EXPERIMENTS
rhis fdure. B€eu!€ small€r land mass6 (isPreliousvort hasdenonitlar€d that th€ses- lands,co.rin€nbl tEgmcnts)de not adequt ly
so.al cycleof cmpeBtur€son land mass€s
ca. r6olv€d i. our model. wc cad ey litde atlout
b€ sirnulaled
wnh a twGdinedonal erergy- scasonahy
in th6e rcgions.
Our r6ulG should
balance
climatemodel.Tl s isa Ihemodynamic rhcrcfoGbc coBid€rcd s€Nitivity €Iperimenc
mod.l rhrt elculatG t€mp. ru6 6 a funclion ratherlhan rihulalions of climr|e.
of th€ planet\ eneryyrccciptand geognphic
lariationsi. land-s€adisrdburion.
The geo- RESULIS
Figur6 I and 2 illwtllte the Janury and
eraphic6fieo i! definedin l€rmsof dill€rcnG in
hcarcapacilyfor latrd and water{Nonh d al., July temFntu.B and tbe annurl Bnge ot
1983).Mod€ldclails,asumptions,
for thc P€mian (Kr?znian)ol
andpalame' rcmperarures
terizltions hrlc ben disclssedehe*here Pangrea.
Our disNion feNs on theSoulh(Nonheral.,1981.l98li Cro*leyetal..198?). €h Hebisphcreof Pangr€x,becrus.fie bulk of
Ewn lhough many ffrdback arc not includ€d th.landnN w6 i. thish€misphere
andshould
in th€model,simulations
compnrefavorably
to theretorerecordlaiSeseaso.al{ycl€vadalions.
morccompl€xclimat€nod€ls in lerns of strsiMean monthly Janulry tenparuturs exCEOLOOY.
v 17,p 457460.May1939
cr€d€d30 'C over a lary€alel (FiE. 1a);'miF
mufl t€mpcnrurc in intedor P!nt@ v.rc 38
'C- aboul 6 'C wdmcr thln mgimum dodelsimuhtcdl€mpentul6 for tbe pr6e Eur&sim
were!
lrndmais(Nod €l d.. I983).lf Prnsa€a
bighplarou (Southsmard H!y, l98t), thls€
tmperatules would bc r€dm€d (d K zba.h
lrd Callimorc, 1989).bu bc srong s€aerllity
vould rdnrin unlessthc pblesu wereic€ covercd whicbdG norsc.m to hrvc bc.. th. ca$.
Chanscsi0 rh€sealot|ll cydc of inel'don (not
shown)duc to orbitd F.turbations (thc Mil.tkovitch efi€co r6uh in naximum sunmer
anF.Ntul6 of 42 oc. B@usc m@ mon$ly
temp€latl|l6 rcpfts.nt night aod &y av€r46,
whichareclmdonly 6. l0 'C l€ssrtun daytine
higts. our ftsulrs sugglsttb.l intedor drytime
lwiflum tebperaturcsnay hrv. crceed.d45
The lars€atr.ual cycle(Fig. 2) rcflec6 borh
sienifica sumnerwlmiry rnd wilter cooliog;
rh€.ei5. luSe as in tb€Soudem Henisphcre
wilh *inter tedp€mrurcs
<0 oc (Fig.lb). Tle
maximum nrse in leftp€nlur€s (50 oC) is
hrye. thln ttat ol thc model{encr.t€d prcscnl
climte (Nonh el d., 1983),and dc ovenll e.!!
of larye (>40 "C) s€aenal cyclc cbaryd hs
ircrc$€d by a factorol eighi Suchr hlgc range
d Sib.o..ur. todry only io nont€m Cfida
ria (Crutcherand M6.nq 1970).
Summ€rpohr tcmp€Btureswerc low (0-5
"C) h cltt€m Auuralia (Fig. la) and Sibcri!
(Fig. lb). Io lbc $r.nc. of otb.r forciry (COz
or chang€sitr oc€ h.ar trN!5pon),th6e 6ults
are compdible with high-lditud€ gbciation.
Gotrdwlnm glaciatioruw..c nc.ring t flninatior in lal. Palco€oiclnc (crov.lL l9E3: CaDutoand crowell. 1985).but th€r€is somc
evidencefor i@ on et$€rn Aultralia (Crow€ll,
1983iFig. la) and [cibly Siberin(ct Ep Gondwanaon the SourhemHemispherc
*a- bad lirtlefunberefi€d on naximDrnrnpcn
lhleyn, l98l). Suchcondnions
arc comparible sonalremp€rature
cvcl€sn betesFdwithsone tures{37.8oCb€forevs 37.4'C aftcr),because
enh low sunn€r temperatures
allowingpreer cxpedmenlsutilizing simplifiedeeogaphv. he areaol landexFsedto maxifruDsumm(
valionof p€rnanents.ow fi€lds(se Crowleyet Holdingtbelocationotan idealized
condwana elar insolationthe sourhernsubrropiG)!e
al.,1987)fixed(Fig.3a),
westarted
wirhanid@liredkuma'd the sme in both configuration.The
In anothersetof experiments
*€ evalDated ru$ia blockspamled tlom condwanaby a 20o small impactof NolthernHenispheielandwbich of tbre€tacroBv.! mosriesponsiblefor st p of ealerandsquentiauyreduced
thedis- nrlts on SoulhemHemisphere
summertembigh SoulhemHen;phere tempenrurcs:
in- ranceb€rw€u thel*o landmasses
by 5.0dsrip6. p€aturcsreUects
thefacrlhat naximum*amcrelx€donti.entality dDeto couisionoftjnrusunrilftey collidedslongl0oS( rheAlleghanian, ins on thelwo landmasesis si\ monthsourof
sia and Condsanqa 10" laritudenonhwad Hercyniansulurezonein rhe late Carbonif
migBtio. of the enrireblocft betwe. the lare
In anorbersd ofsensitivny
experiments.
we
(W6tphaliu, 305 Ma) andKaCarbonitercu!
The resulrs(Fig. 3b) denostate rhar the elalualedlbe€lT€ct
of Condwanan
ia coleroi
anian (255Ma),or posr-Saknarian
(pst-270 converSenc€
ol rbe rwo landma$es
had lifile haximumt€mperarurcs.
An iceshedapproxjMa) melring
ofcondvananice.Southem
Hem- eflecton Gondwana
unril it reached
final clc mat€lyhaltrhes;e ofthe Goidwananicesheer
spheremaxirnumremp€ra1ur6wercusedasan sue. aier whichtcmp€iarures
incrsed aboul ar maxinumeienr (ct Bambacb
d at.. t98l)
indexof the reladveinporrlne of the thre 1.5 'C. The l0o nodward molernentof the vs place.t
on therdealned
( Fis.
sup€rcontinenr
Pang.ean
bl@k berwecn
tbe Weslphaliar
lnd 3a).For thiscxpe menta vesionoi lhe model
The efect of lhe collisionoi Laurussiaagainst Kaanian(Bambach
eta1.,198I i Scotese,
I 986) wjth regionally
v{ying albedowasused(Hrdc
eral.,1989).ThehiSb* albedofor theiceshecr
redu6 theiadiation
budeetoflhe planerrcsull,
ine 'n s'gnifiontl)low€rrenpeiarursoverrhe
''Ilat ice
sheet(Fie.3c).Theicc-sheer
rnp€raturcelTeddioinishes
ro l/eofils pealvatuein
abour2000km (cf. Nortft.1984:Manabeand
BrMoli. 1985).equarorialtemperarureij
onll
decrcAingb]' -l oC. Compa.isons
bctween
energl-blanceclimale model and geneEl
circulation
modelsinulaLions
oi rhisalbcdocf
fectindiBlea similarpafielnands€nsitivity
foi
the lAl glacialmaxidun (Hrde er al.. l9tl9).
However,because
climareinodclsmayolerer
tinatc lowlalirudcrcmpe.aurcs
du ng $e tan
glacialmax;mDn(Rind and Pereer1985),a
funher low larirlde decrcse of a fcw de8res
may havcoccuded.A largerice sheershould
havetunherdeoe$ed remFEratures.
Model resultsthcrcforeindiBte thar grar
sDfrrner
wamingoccutredon rheCondq?nan
landma-ss
whenir wascentered
on lhesubrropics.The collisionof Lautulsiaagainsrcond
wanahada minordiecronmaximunSouthem
tlemispierewaminS.MehinScondwananice
probabhhad a greatereffec!on hemispherk
Figuro.r, Simulatedlemperature6tor X.zanian (255 Ma). aj Janu6.yi
b: J!ty, Base map3, *ith
lhadedlopojraphy
rorreter€nce,.rc
r.omscor;se(1es6).
op"n jre","r"iro
cover(rronParish6rat.,t986).
"i
""ia.niiii,i..
DISCUSSION
Preliou geologicstudieshave suggcsted
lbat $e la€e Pa.Baea.lapdmN shouldhave
b€enrelatively
drv (e.g-,Robjnson,
l97li PaF
risheral..1982).Ttis bypolhesis
har.ow been
suppo.ted
by alculatio.swilh acenealcncuhtion climatemodel(Kuubachand callimole.
1989),which estinatctbal nel precipitarid.
m'nus€vapoaliononanid€alized
(Tdassic)su,
per@ndnent
wouldbereduc€d
by 50?.
ou own calculalions
sugSest
rhat sersonal
cycleson superco.ti.en6
wereverylarg€.Hon
rel'ableare ftse rsul6? Ttc relationbetwee.
ludmss sire and se$o.ality are wdl undeF
stood and sal;faclodly simulatedwith climate
models.
Fudermore,inclusion
d
ofnonlinear
modd CO: nay modifyrheakolulevalues
otmaxima
fcct5nor includedin rheene€ybalance
do not significandymodify s€asonalit!calcula- andmjnimabrrlessothcange(ct C.owlcyet
andCallinore,1989):wirtions(Crowhyetal..l9E6;Hydeetal.,l9E9).If al.. 1987iKutTbach
wouldprcbablysrillbe<0'C
3nlrb'ng,the eneey balane modeltendsro t€rrenpcatur€s
ssrulity (Norther al., in highlalitudes(cf. Kutzb$h and Gauimorc,
slighdyunderestimate
Hlde
er
al.,
1989)
1989).t-uah(morc.incrca*dpolewadocean
l9llli
How m;ghrthe rcsultsbe affecrcd
coastalrcgionsnorc rhan
by hiSh* h€atfiansponalTects
at pr6e.t rhc
in meancncularion?continentd
int€no6.For€xampl€.
COt lerehor pastchantes
Figure 2. Annual rangeol renper.lur.! lor K.zanian (255 fr.). [ole th.t nod.l-genedted p.al
i. annualcycle i3locaredin cenl€rollandmass, where.. in no.e complcxmodeB (and..lure) ll
i3 3hifted easlw.d. Shifi refrecb "downllream" cooling in wBledy wind boll, . p,oce8a nol
adeq(alely lrealed by onergy balanc! model.
climareol oonhwenEuropc(ht 55 60oN)is
modified by the Gulf Suean. Y€1 kningr.d
(60pN). lo.st€d ls tnan one-fifih of the dn'
tanceirro th. Eurdian laodrnrss.hs vcry cold
wirrcu. Very laryeannualcycleslh€rcfor€ap
p€r lo b€ a fealureof sup€rconinenrs
evenwilh
diileienr scenariosof COl or o.ean circulalion
chang6.Ir isdifilcllr ro re@ncil!slch highs$'
sonalitt waththeterm"equable, whicbiseme'
tin6 uled to der be supercondn€nt
climar6.
Ou. r6ult5 may be of int.r6t lo si€otisls
enmining the disrnbulion
of clinate-Fnsidve
Fdimenb and f6ils. The lar8c renee of
lenperarur€smay hrve affect€drhc distribution
of len6tdal plantsanda.iDals, pcrhap6ploducitr8 r s.asonalsignabr€ in dinributions morc
exrene $!n any ffcuring at pen1. Addiiiorally,naximun €mp€nturcson sublropicd
condwloa (38 42 'C), which sc€ededrbe
presenldaximum by Glo t, aDdlelchendsytimehi8hs>45'C. mayhavet6!ll.d in p6dsof
the superontinert interior that were viftually
The lesulrsalsopreseat
sme dilemo6. Foi
eranple. thc irca of h€e annualary€ or
temp€mtures
{Fr8. 2) oi Condwana((0"S)
coincid6 wirh a *elltlown fNil rcptilelocalny in SourhAlrica (Parist et al.. l9E6). How
couldlargercprils havesuflivedlo* vintet
t€npenrurF (Fig. lb)? lf CO2 levelswere
higher.wint€rtemp€nluB wolld inc'€&. but
40
Flgure 3. Sen6ilivilyexperi.
n..Is to delernin. cau6es
ol GondwananlemPeElure
.xtr66.
a: Sch.manc conlincnlal configuralio. core.ponding aPproxlnalely lo
la!russia (nodh)and Gondwana (soulh) 3ap..aled by
'0" ol l.lilude, O.3h.d llnes
rl.r to so |aril!d. incremenls used to dGe g.p belea€n lwo landfiaa.e in
do.ringerpe nlnr (p.d b).
While area in low.r lelt
ol Gondwana indicate. gla.
.laled region In lc6/no-ice
erporlmenl. b: Ell.cl ol
L.lrlrsia colll.lon on marinlm slmmer Go.d*ana
rcnpe.alu.e.
a3 9.p belYv.en lwo landna$€! .equ.ntially clo6ed by 5q h$
llde incremenlr, For 0'
clo3!re, we also plolled
t6rr lor unilod bloci wilh
Gondwana-siz.d ic. .heer
(pan c). c: JaNa.y lcm'
P.rature chang€. slong lwo
dllilrenl lon9ll!de lran!*ls
dle to removal ol Go.d-
10 N
€ ooclingerpedmsnt
e
20
-20
1 0s
h
b€ 6fied
-r0
,15
90s
-5
Degrees Lditude S€pa.atun
-30
so nould thear.a of very highsumn.r remp€ntur6 (>35 oC). CO2 would transht a {,inrcr
mod€l-dabdiscr€pancyinto a suhner hodcl&l! discrepancy-On. pcsrble explanationfor
thc S{ulh African .scmblrgc involv€ss€alonal
migntions ro r,lmer clinat6. Orherexpllnalions mayalsohaveto b. €Ebined.
Ou. ltsult! may dlo have implicationsfor
Pcrmiln €xrincliou. Th. pGtulded onsd ot
nlximum warminS/dryinein the Sourh€m
Hcmitphtre would hrvc pddat€d dnryp.lF
mce of fte nljor Southem Hcnisphcre ac.
shee$ (i.e., po6t-Salm|rian.265-270 M^t ct.
YEV.R ad PoveU,198?).This u!.sdon rF
prcximatelycoincidq witb a major vencbrare
turnolerin the Low€rPcmian(Olsn, 1982i
Bcnton,1987).Ttis cvent\ras charaderiz.dby
the rile of nore diougtGtol€Ent rcptil6. Th6
coincidencesuggeslsthal clinatc chuge nry
hav€ influencld the biolic tansition. Funher
morc,b@u. rcquted rdlplat on! of lerc$rial
biola to Fasondity excc.d€dpffint linits, rtte
biob may tuv. b€enmorc s.nsitive|o eNironmcnralp€nurbstionsat tie ed of the Pemirn.
Cro*ell, J-C., 1933,Ie 46 @d.d o. Go.d*rDrr
@n!ne s: C@logiql Sai.ty of Sdlh Afrna
Tl'Nclioq
v. 86. p 237 262.
Cd*ley, T.J., 1988, Pll@lid c nodelljnl, D
schl6ined, M.E.. .d.. Phtsiolly b.*d Foddlire and 3innliton of cliflk
and cfironc
chansc: Dordrcchl. Nerhcrlands,(luw.r,
P.883 949.
Cosley, TJ.. Sbo( D.A..M.n8el.J.C.,lDdNonL
G.R- 1966,Rolc ot s.Nn.lily in $e .vol ion
of climrreduringrh. 161 100 million ya6:
S.ien€,v. 231,p. 579 534
Cro*hy, rJ.. Mene.l.J.C.,ad Sho4 D.A., 1987,
Condunrlandt eodl
crclc Nature,v. 129.
p. 803 807.
Ctutcher.H.L., aDdMesc J.M., 1970,S.l6t d
l.vel h.i$q t nFntu6 dd dcw poinc for rbe
Nonnm H.misph.r.: Wshington, D.C., Chi.f
oI N.val Op€Brions,
ReponNAVAIR s&lc-
P.rnh, J.M., Psnh. J.T.. md Zr.glei, A.M., 1986,
pll@elolr4by od FldliPmim.TiiNic
ma!olo!, ud inpli@tioE for TheaFid disriburion,rt Holton,N.,MrcLan, P.D.,Roth.JJ.,
ard Rorh,E.C-..r|5.,Trr cology ard biologyol
.moll-fire
ep 16: Wanin8bn, D.C., Smithenian lnstnulonP6, p. 109-lll.
Pltth. J.T..ziecler,A,M' andS@rB, c,R,, 1982.
Rrinfallp.treNandtn di5tibudmol@lsmd
dapodr6: Pala@!.o8aphy.Prla@linatology.
Pahel$logy. v 40,p 67-101.
Rin4 D.. rnd Petcr.D,. 1985,T.ddfial oldirions
at $e 16| sl.cill hdinun lrd CLIMAP e
surfae lcnFEtur. 6rinrt.s: tue they onsinerd:Quatcrnq Rs,rch, v.24, p. I 22.
RobiNn. P,L. | 9?1,P.lmlinrtoLAy add@ntiDen|!l dtifi. t Tlning. D.H.. .nd Runsd, S.K..
e.,s.,Irplielions of conrrncnddnn to onh ei
eDc (Volunc l) New Yorl AmdemicPres.
t.451 476.
S<ot6€,C-R.. 1986,Ph!..r@ic r@GttucrioB: A
ncwl@t rr theNnbly oI Asia:Univ.uilyoI
Tera l.stnuietor O.ophtsicT{hniql Repod
EFhtya O.C.. 198l.l2t P.mirn ie-ffiim d.Fib oI lhc AtklD Forma on in thc Kolym! Rivcr
hdd*lc6 csiol' U S.S.R.,
rn Hmbr.t, H.A..
and Hlrlrn4 w'a.. c&.. E nh! pePl.ist@m
ghcirl @d CambndseEnSllnd,Cambnds. Sou$.n, J.R..and Hrt. W W. 1981.clobl sd|
menhrynN b,line ands levelch.ng6,,t
Unive6ny PRSEp. 2?0 273.
Enilirni,C.,ed.,Thcs, Volun.?:The@nic
Iiydc, W.T.,Cro*ley,TJ., Kin, K -Y., rnd Nonh,
lithGphcrerN.* Yorl. Wilev-lnl.ei.na.
G.R.. 19E9,Comtarnon oI CCM sd .ne4y
p. r617 t634
bd,@ nod.l sihulrtioN of wDal tdFc
ruE ctm86 ow th. 16l l8,0OOye6: Joumal VcveE J.ltl, rnd Por.ll, C.MCA' 1987,Lik Palozoic ghciat cpidj6 in Gondwand.nd re
CONCLUSIONS
(uub.cb. J.E., .nd c.llimoE, R.6.. 1989,P.n8an
nd.d i. td6SBivc{e3r6iv.
dep6nioMl sL ModeledseaeMl tlEFnlure llucrrntioN
qucn6 ir Eurlneno: C.ologi@l Sdi.t!, of
dinat6: M.ganonsa of $. [email protected]
v,98.p 475 43?
in the SouthemH.nisphcE of Pengaea
Ancdo Bulletin,
ar€vcry
Jounal of Geophrsial Rsrch (in p6)
R.A.,Smnn,A.G.,a.d Vina F.J.,1986 Wallae.J.M,.aid Hobbs,Pv.. l9?7, Ah6ph.dc
la€e,monftly seerases
in thesunher>35 dC Livermore,
bt Pah@aic ro ady M@ic evohdd of
eere
A. infilducbry s!rycy. Ne* Yort.
aod d.)rime hi8lrsproboblyexc€€ditr845 oC.
Aedenic Pr6. 46? rr
P.]l8re: Ndure, v. 122,p. 162 165.
Thc collisio. of lrurulsia had rchdvely liitle M.nabe,S.,&d [email protected],Th. innueneot Zieglc,A.M..sold, C,R..McKcruw.w,S..Johneflecl on the SouthemHcmilpherese&sondcy$n, M.E..and&mbach.R.K., 1979.Plleozoic
cordr.nbl ie shp$ oi th€clidrk otan ic .se:
p.lcotcos8phr: An.u.l R.vEs of E nh rd
Joumll of Geophy5i6l Rerch, v. 90.
cl€stchansein Condwsnmie coverwasprct
Pldcnry sci.ne. v. 7. p 4?3 502.
P 2 1 6 ?2 1 9 0 .
ably th€ Ino6t impona factor.fl€.1ing tem,
Nonh, C.R., 1984,Thc sFdl ie €p iBubilily it
p€raluresin thc SoulhemHemisphere.
diltBive clim c nod.ts: Joudel of thc AhG
2. tow summertemp.Btur6 in Siberiaad
spb.ric S.i.6
r. 4 l, p. 3390-1195.
ACXNOIVLEDGMENTS
eatt€mAusnali! would r€sultin cotrdidonsta- Nonh,G.R.,C!hrla.. R.F, md corklcy,J.A. Jt..
Supponedby Nalionrl S.iene FounrtrLionGrms
yonble to ghciatior. Tlcr€ i! someevidencefor
ind ATM87-15079.
W.rhankI Par
1981,E erSybalMe climrlenodels:Rcviews ATM87-22145
Spae
v,
19,
ot
Gdphylic
Md
PhysG.
ie at thisrim€ in both rcdos.
9.91 l2l.
3. Th€ hiSh sunm€r temFralures and Nonh,
C.R., Mcngel.J.G.,and Shon.DA. 1983. MrnEripr r@ncd ocrolEr20, 1988
ma edwnality in thcSoulhemHedisph€rc
Simplcen.l3ybahncemodclr$lvin8 lhe$R.vi$d oanenpt eueiv.dJ ury 25.1989
$E tud rh. otrtinenB: Applidion b tnc 6iG
Mlrqifl
a@Fet Janury I L !9E9
should havc significlntly afrecGd aftestrial
@ni6l $@ry of $. @ 46: Joud.l oa
pl|nr and aninal distdbutio$- Tt6c 6ndirio0s
GophFidl RMrch, v. 88, p. 6576 6586
ue ditficult to r€.oncil€with equable"climates
Olson,E.C.,1982,Exdnctio6of PernimandTn6sic normlnn. vcn.brat s, iz Silver, I-.T., .nd
Scb'nt- tH.. eds..G@loCiol inplialioB of
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