BulletinofGlaciologicalResearch21（2004）18◎JapaneseSocietyofSnow andIce

lArticle
Stabilityofdrjftingsnow・tyPe Perennialsnow patches
G．E．Glazirjn＊，Y．Kodama and T．Ohata

InstituteofLowTemperatureScience，HokkaidoUniversity，SapporoO60−0819Japan（ReceivedJuly25，2003；RevisedmanuscriptreceivedOctober17，2003）

Abstract

Perennialsnowpatchesexist one kilometerormorebelowtheclimaticsnowline atthe sameplaces for manyyears andhave verysmallsizesin autumn．Theycould not exist stably without

powerfulnegative feedbacksin their sizes throughablation／accumulation．Those feedbacks were
examinedforsnowdrift・typeSnOWpatChes（Hisago，KaigataandHamagurisnowpatches）inJapan．

Dataonthesesnowpatchesthatwereobtainedoverperiodofmorethan7yearswereusedtoobtainindexesofsnowpatchsize，aCCumulationandablation．Theresultsshowedthatwhenthesizeofa
SnOW patChin autumn waslarge（small），the accumulationin the following winter became small（1arge），andwhenthesizeofasnowpatchatthebeginningofablationperiodwaslarge（small），the
ablationinthefollowingsummerbecamelarge（small）．

1．lntroduction

There are atleast threeimportant reasons forinvestigatingperennialsnowpatches．First，they are
trよnsitionalformsbetweenseasonalsnowcoversand

glaciers，and their characteristic change to snow
COVer Orglacier wouldindicate anevent ofclimatictheannualmassbalanceofsnowpatchesisstrongly

affectedbyyear−tO−yearChangesinseasonalweather

conditions．

Despitethedependenceofsizesofperennialsnow
patches onyearlyweatherconditions，theycanexist

formanyyearsinthesameplace（Glazirin，1985；1997；
YamaguchietaL，1998）．Yearlyvariationofweather

Shift．Second，theyconstituteasignificantelementofCOnditionsis notlikely to regulate perennialsnow

highmountainlandscapes and their change can sub−patches for their stable existence．There must exist

tigatedusingsmallersnowpatches．
Current perennial snow patches generally exist
aboutonekilometerormorebelowtheclimaticsnow

andGlazirinetal．（1993）suggestedthatthereexisted

Stantially affect highalpine summer runoff（Shultz，mechanismsbywhichtheexistenceofsnowpatchesis
1956；Sosedov and Seversky，1963；Higuchiet al．，
Stabilized．Ifsuchmechanismsdidnotexist，thesnow1979）．Third，issuesrelatedtoglacierssuchasbottom
patches would either grow or disappear．Based on
iceformation（Kawashima，1997）canbeeasilyinves− resultsofstudiesinthe Pamirs，Glazirin（1985，1997）

Stabilizing feedbacks such that mass balance wasinverselyrelatedtopatchsize．Wespeculatethatthe
Same Stabilizing feedback works also for snowline，Where，Onaregionalbasis，annualsnowfallislessthan snowmelt．Therefore，theinitialformation of patchesinJapan．In this paper，We review the feed−perennialsnowpatchesresultsfromthelocalprocess
Of snow accumulation，perhaps by redistribution ofback processesonsnowpatches andshowthat theyalsoapplytosnowpatchesinJapan．

makes the accumulation／ablation different from theregionalmean．Forthestableexistenceofperennial

2・Stabilizingprocessesofperennialsnowpatches

SnOW and／or alocalreductionin ablation，Which

SnOW patChes，thelong−term maSS balance must be
ZerO．Otherwise，they wouldbecome glaciers or sea−
SOnalsnow covers．Since snow accumulation andablationdependmainlyonmeteorologicalconditions，

Stabilizingfeedbackprocessescanbedividedinto
two groups，aCCumulation and ablation processes（Tablel）．Onemaydominateortheymayinteract．

＊Current affiliation：CentralAsianResearch HydrometeorologicalInstitute，Tashkent700052Uzbekistan

2

Bulletin ofGlaciologicalResearch
Tablel．Classificationoffeedbackscontrollingaccumulationandablation．
Mechanisms Controlonaccumulation
Maximum
Feedback
prOCeSS
SIZelS
1imitedby
thesizeof
depression，
Typicallocation

Depression

Formation

Snowdrift

Control on ablation
Accumulation Changein
Ablation
Breakdown
ofcornices
SOlar
decreasedecreaseswithradiationwith CauSedby
Sizechange debris
snow patchSize．
Lee side ofAnylocation， Anylocation， Ridge
ridgesandhills typicallyona
north−facing
Slope
Any
CorniceSnowdriftAny

ユノ．．1（∵〟川J／山／／り〃♪川（、（、J∫ 、∫

For perennialsnow patches to existin a reglOn
far below the regionalequilibriumline altitude，thesnow pack cannot be a uniform layer but must be
redistributedandaccumulatedpreferentiallyinsome
locations at magnitudes greater than the regional
meanablation．Suchaccumulationoccursduetowind
redistribution of snow and avalanching．Favorable

topographyforaccumulationbywindredistributionis
depressions in flat terrain or a slope with abrupt
Changesinsteepness．Thetopographylimitsthesizes
Of snow patches because once a depressionis com−pletelyfilledwithdriftedsnow，thedepression，Whichinitiallyfavoreddeposition，nOlongerexists（Fig．1−Ⅰ）．

Whensnowpatchvolumeexceedsthevolumeofthe

depression，wind ablates the more exposed snow．

琴ミき∋く￡房
Smallsnowpatch

SmallsnowpatchⅣ

LaterinablatioTlperiod

V Breakoffplane＼−

Largesnowpatch

Earlierinablationperiod
Breakoffplane＼−、Largecomice
Fig．1．Schematicdiagramsofstabilizingmechanismsofaccumulation（I，ⅠⅠ）and ablation（lII−Ⅴ）．

Glazirin et al．

、■〜

Therefore，aCCumulationonasnowpatchisinversely
processesofablation．Liketheeffectofincidentsolar
proportional to the size of the patch relative to the radiation stated above，this effect can be seen more
Size of topographic depression（Fig．1II）．Alarge

amount ofsnowcanaccumulateifthepatchissmall
relativeto thesize of the depression，andless snow
accumulatesifthepatchislarger．Snowisrapidlylost
ifthepatchislargerthanthedepression．
Those mechanisms were briefly discussed by

Clearlyforsnowpatches onnorth・facingslopesthan
forsnowpatchesonsouth−facingslopes．

Anotherstabilizingmechanismofablationcanbe
SeenWhentheredistributionofsnowbyavalanchesas
Wellassnowdriftoccurswiththetransportationofa

large amount ofsplintermaterial，dust or sand，andInoue and Matsuda（1973）for Yukikabe perennial
thesematerialsareprogressivelysurfacedasthawing
SnOWpatChinDaisetsuMountains，Hokkaido，Whichproceeds and protect the snow patch from further
is formedleeward of a ridge by snowdrift．They
melting（Fig．1−IV）．Thisprocessresemblestheeffectpointedoutthattheupperpartofthepatchisflatat
Ofdebrisondebris−COVeredglaciers．Whenthethick−thesameheightasthatoftheridgeregardlessoftheamountofsnowdriftinwinter．Thisindicatesthatthe

Size ofthe snow patchislimited by the topography
mentioned above．

Thereisnostabilizingprocessesforsnowpatches
OnWhichsnowaccumulatesprimarilybyavalanches，
becausethesizeofthesnowpatchdoesnotcontrolthe
magnitudeofavalanching．Thistypeofsnowpatchis

COntrOlledbyseasonalsnowfallandbythecontribut・

ingareaoftheavalanchezone．

ユユ．・1／｝山／／（りJ♪J■り（、l−∫∫（〉∫

Ablationprocesses，Whichleadtostabilizationof
SnOWpatChsize，Canbe foundinthe effects of solar

radiation，debrisandbreaking−Offofcornices．

The largest energy source for ablation of snow

ness of the debris layer or the amount of splintermaterial，dustorsandisjustsuitableforablation，it
enhances melting．However，if thelayer of debrisis

Verythin or the amount ofmaterialsisvery small，
progressivemeltingwillcausethematerialsthat arepresent inside the snow patch to surface and thethicknessofthedebrislayeroramountofmaterialsat
thesurfacewillsoonexceedthethicknesssuitablefor

melting，and the surfaced materials willreduce theintensityofmelting．
Aspecialtype ofstabilizingmechanism of abla−tioncanbefoundonsnowcornicesformedusuallyon

ridges（Pertsiger，1984）（Fig．1−Ⅴ）．Large cornices
become perennialsnow patches（Pertsiger，1984）．

When a cornice growsand becomeslarger than a
Criticalsize，Whichis determined by the physicalpatches，aSforsnowandglaciersingeneral，issolar properties of the cornice，meChanicalbreak−Off canradiation（e．g．Munro and Young，1982；Paterson，occur．MechanicalbreakTOff does not occurif the1994）．Theintensityofthesolarradiationdependson COrniceissmall．Thelargerthecorniceis，thelarger
Slope，aSpeCtandshadowingbysurroundingtopogra− theamountofbreak−Offis．Thisisonetypeofstabiliz−phy（Arnold et al．，1996）．Thegeneraleffectofslope， ingprocessesofablation．

aspectandshadowingisreductionintheintensityof
incidentsolarradiationreceivedbythesurfaceofthe

3．SnowpatchesinJapan

patchisshadedbythesurroundingtopography，SuChknownsnowpatchesinJapanaresummarizedbelow．

themagnitudeoftheeffectisgreatestonpatcheson、フ．ノ．〃ね（脚＝…川・♪〝／（、ん

topographyonshortTWaVeradiationisalsoimportant，lation of drifting snow on thelee side of a ridgein

SnOWpatCh（Arnoldetalり1996）．Theslopeofasnow
patch，eSpeCiallyoneonanorth−facingslope，becomes
There are no glaciersinJapan，but perennial
SteeperaStheablationproceeds（Glazirinetal．，1993）． SnOW patChesexist（Fig．2）．andtheyhavebeenwell
Therefore，theincidentangleofsolarradiationtotheStudied（Seesummarypapersby Higuchiet al．，1979
patch surface becomes smaller，and eventually the
and Tsuchiya，2002．）．Data on the three most well−asridges（Fig．1−III）．Thiseffectdependsontheaspect：north−facing slopes andisless patches on east・and
Hisago snow patchislocated on a south−eaSt
WeSt−facing slopes，and thereis almost no effect on
facingslopeat anelevationofabout1700m a．s．1．in
patchesonsouth−facingslopes．TheeffectofshadowT the southTeaStern part Of Daisetsu Mountains，Hok−lng Of the snow patch surface by the surrounding
kaido（Fig．2）．ThispatchisformedduetotheaccumuT
dueto theenclosednature ofabasin（Arnold et al．，
1996）．A snow patch that outgrows the area shaded
from the sunis ablated more．When the ablation

proceeds and the snow patch becomes smaller，thepossibilityofrecelVlngSOlarradiationislessbecause
the initially frequently−eXpOSed area of the patch

winter．The patch starts to meltin April，and themeltingendsatthebeginningofOctober（Kodamaand

Takeuchi，1993）．The mean area and approximate
depthattheendoftheablationperiod（endofSeptem−ber）are8．5×103m2and7m，reSpeCtively．Yamagu−

Chiet al．（1998）estimatedthe annualmass balances
Surfacetosolarradiationdisappears．Thentheinten− Since1890basedoncorrelationsofmassbalancewith

Sityofablationbecomessmallerduetothelessexpo−
SuretOSOlarradiation．Thisis oneofthestabilizing

Summertemperatureandwinterprecipitation．Anicebodywasfoundatthebaseofthesnowpatch（Kawa−

BulletinofGlaciologicalResearchイ

Fig．2，Mapofthesnowpatchesanalyzed．

shima，1997；Kawashimaetal．，1993）andtheexistence

ofthisicebodysuggestsamoreglacier−1ikecharacte
Ofthesnowpatchthanwaspreviouslythought．
The thickness of the snow patch at the end ofnablationperiodweremeasuredoveraperiodofseverablationis calculated using the summer mean air
temperature from thelowLland Asahikawa station（Kodama andTakeuchi，1993）：f

years，from1991to1997．Thesurveyswerecarriedout

on various dates from the end of September to thebeginning of October depending onlogisticalcondi−
tions，butthedifferenceinsurveydatesconsideredno
to havegreatlyinfluencedthesize and depth ofthe
SnOWpatCh，because the meandaily airtemperaturet

α＝15．3（7．7了も＋10．6）（1）

Wherea（kgm2）istheannualspecificablationand7i，（℃）isthesummer（fromMaytoSeptember）meanair

temperature at the snow patch estimated from thelow−1and Asahikawa station and alapse rate．77，isCalculatedby

ち（ろ）＝右（る）＋γ（ろ−る）at the patch was near or below O℃．Data was col−1ectedalongatransect，butonlydatafromthethick−（2）

Whereろ（＝1700m）istheelevationofthesnowpatch，Zb（＝110m）istheelevationoftheAsahikawastation
est centralpart of the patch were used because oandγ（−6．5×103℃m￣1）isthemeanlapserate．The
yearlychangeinsnowpatchsize．Theaveragedensity
ofthepatchisabout650kgm￣3（KodamaandTakeu− annualspecificaccumulation，C，WaSCalculatedfrom
fchi，1993）．Consequently，the average annualspecific the difference between the measured balance andCalculatedablation（Eq．1）andtheresultsaresummar−
massbalance，b，iscalculatedtobe650dh kgm￣2a￣1，izedin Table2．
where dhis the annualthickness change．Summerb：annualmassbalance，Sb：aCCumulatedmassbalance，
Table2．MassbalanceofHisagosnowpatch．

7；（ろ）：Summermeanairtemperatureatthepatch，a：annualablation，C：annualaccumulation．

Year
1991
1992
1993
1994
1995
1996
1997

∂

7も（ろ）

5占

×10kgm￣2a【1 ×10kgm2
242
420
−411
53
162
−71

℃
0

242
662
251
198
360
289

6．0
5．8
8．2
6．9
6．0
6．5

〟

×10kgm山2aAl

872
848
1134
971
872
924

C

×10kgm2a￣1

1114
1268
723
918
1034
853

5

Glazirin et al．

UnlikeintheanalysisofdataforHisagosnowpatch，
dataondepthchangeofthesnowpatchwereusedin、−ノ．ユ 〃潮岬／′Jイ∫〃りJぐ♪（／／（ソナ

Hamagurisnowpatchislocatedona northeast−

facing slope at an elevation of about 2730 a．s．1． this analysis（Table3）．In Table3，Hsis the mean
betweenMt．TsurugiandMt．TateyamaintheNorth− depthofthecentralpartofthesnowpatchprofilein
ernJapanAlps（Fig．2）．Thispatchisformedduetothe Spring，andIhisthesamevalueinautumn．Accumu−
accumulation ofdriftingsnow at the NNEside ofa
1ation，C，isthedifferencebetweenthedepthinspringpass（AinFig．2）．ThepatchstartstomeltinMay，and andthatinautumnofthepreviousyear，andablation，

themeltingendswhensnowstartstofallinOctober．
This patch was surveyed over a period of25years，

thatinautumnofthesameyear．

andapproximatedepthattheendofablationseason

ふ？．んJ短（J山ゴタ研ぐ♪JJ／（、んsured seasonalbalance data．

and the melting ends when snow starts to fall in
November．This patch has been surveyedsince1972

a，is the difference between the depthin sprlng andfrom1967to1991（Ohataeial．，1993）．Themeanarea（endofSeptember）are7×103m2and20m，reSpeC−
The Kaigata snow patchislocated on atively（Ohata et al．，1993）．The snow patch was sur−
SOutheast−facingslopeatanelevationofabout1400m
Veyedtwiceayearin230fthe25years，insprlngat
a．s．1．onMt．Chokaiinthenortheasternpart ofHon−
theendoftheperiodofaccumulationandinautumn
Shu，themainislandofJapan（Fig．2）．Thispatchisalso
attheend ofthe period of ablation，prOviding mea−
adriftingsnowtype．ThepatchstartstomeltinApril，Thedatausedherearedataonsnowpatchdepth
distributionalongatransectlinefromabasepointon（Tsuchiya，1999）．The mean area and approximate

from north．The surface altitude was measured andOctober）arel．2×104m2and8m，reSpeCtively（Tsu−depth at the end of the ablation period（middle ofthe pass（Ain Fig．2）in a direction60degrees eastthe depth was calculated by subtracting the basal
Surfacealtitude．Thebasaltopographywasmappedin
1980and1990years，Whenthesnowpatchwasquite

Chiya，2002）．Tsuchiya（2001）foundanicebodyatits
bottom，Observed the snow patch s movement andtherefore named this snow patch Glacieret． The

snow patch completely disappeared several times

Small（Ohataetal．，1993）．Onlythecentralpartofthetransectline（betweenthehorizontaldistancesof60m（1990，1995，1998）．Tsuchiya（2002）reported that theandlOOmfromthebasepointA），Wheresnowexisted Sizes of two other perennialsnow patches，locatedbothinspringandautumn，WaStakenforcalculation． higheronthesamemountain，fluctuatedsimilarlybut
Table3．MassbalancecomponentsofHamagurisnowpatch．IhisthemeandepthoftheCentralpartofthesnowpatchprofileinspring，and Haisthesamevalueinautumn、Accumulation，C，isthedifferencebetweenthedepthinspringandthatinautumnofthepreviousyear，andablation，a，isthedifferencebetweenthedepthinsprlngandthatin
autumnofthesameyear．
Year

〃s

1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991

20．7
21．2
19．0
18．0
17．7
21．5
18．2
18．0
22．6
19．3
17．8
20．5
19．1
12．2
22．7
19．4
17．7
22．7
17．3
20．7
18．1
13．1
20．0
18，0
16．5

肋

4．2
6．1
2．7
0．8
1．5
4．2
5，0
5．6
2．1
1．4
4．8
1．9
1．5
5．6
5．6
6．2
9．9
0．9
5．3
1．7
1．4
0．8

C

ma−1
17．0
12．9
15．3
20．7
16．7
13．8
17．6
13．7
15．7
19．1
14．3
10．3
21．2
13．8
12．1
16．5
7．4
19．8
12．8
18．3
15．1

〟
ma−1
16．5
15．1
16．3
16．9
20．0
14．0
13．0
17．0
17．2
16．4
15．7
17．2
10．7
17．1
13．8
11．5
12．8
16．4
15．4
11．4
16．6
15．7

Bulletin ofGlaciologicalResearch

6

that those patches never disappeared．This finding
indicates that Kaigata snow patch is quite near the
lowerlimit forits existence．

Both the area and maximum depth of Kaigata
SnOWpatChweremeasuredattheendoftheablation

periodeachyearfrom1972to1983（Tsuchiya，1999）．

From1984to2001，Onlytheareawasmeasuredbyin
situ surveys or estimated using satellite images andpicturestakenfromanaircraftandonthegroundat

†

1
1
1
1

∈
切
言
︻
×
．
毒
卜
占

periodfrom1972to1983wascalculatedastheproductlinecanbeexpressedasfollows：5〝7（ば＝4．06 ×10￣4A．

（3）

ThecorrelationcoefficientisO．98，andthep−Valueof
the slope of the regressionlineisless than O．001，

indicatingthepositivecorrelationissignificantwitha
significancelevelof95％．The p−Valueindicates theprovabilitythatdeniestheexistenceofcorrelationin
thetwovariables．Smarwascalculatedfortheperiod

from1984to2001usingEq．3，andresultsaresummar−

4
2
0
8
丘
U

a fixed point（Tsuchiya，2002）．The maximum snow
water equivalent，ShlaX，at the end of the ablation

Ofthemaximumdepth，〟∽ar，andmeansnowpatch
density（800 kgm−3）（Tsuchiya，1999）．We tried toextendthisdataset，Smax，uptO2001bycorrelatingit
withthesnowpatcharea，A（Fig．3）．Theregression

6

4

0

2

1

3

月，XlO4m2

2
Fig．3．Dependence
ofthe maximum snow water equiva−
1entofKaigatasnowpatch（Sm以：）onitsarea（A），
0

izedinTable4．Massbalancewascalculatedbythe
SamemethodasthatusedinthecaseofHisagosnow

patch．Theannualmassbalance，b，WaSCalculatedas
thedifferencefrom Smarofthepreviousyear．Abla−tion，a，WaSCalculatedusingEqs．1and2，andaccumu−
1ation，C，WaS Calculated as c＝b−a．Mean summer
air temperature at the snow patch，77，（ろ），WaS

extrapolatedfromdataobtainedfromameteorologi−
Calstationin Sakatalocated 25 km away at anelevation of O m a．s．1．

Table4．MassbalancecomponentsofKaigata snowpatch．b：annualmassbalance，Smar：maXimum snow
Waterequivalentatthebeginningoftheaccumulationperiod，77，（ろ）：Summermeanairtemperatureatthe
patch，a：annualablation，C：annualaccumulation．
Year
1972／1973
1973／1974
1974／1975
1975／1976
1976／1977
1977／1978
1978／1979
1979／1980
1980／1981
1981／1982
1982／1983
1983／1984
1984／1985
1985／1986
1986／1987
1987／1988
1988／1989
1989／1990
1990／1991
1991／1992
1992／1993
1993／1994
1994／1995
1995／1996
1996／1997
1997／1998
1998／1999
1999／2000
2000／2001

∂

S〝7αγ

×10kgmZa】1

4．0
8．0

−5．6
−4．0

4．0

−3．2

3．2
4．8
3．2
0．8

−5．6

4．1

−3．2

7も（ろ）

1．6
5．6
13．6
8．0
4．0
臥0

4．8
1．6
6．4
9．6
10．4
4．8
臥9

0．4

5．7
7．3
2．8
0．4

0

0

1．6

−4．5
−2．4

0

0

0

0

3．7
4．5
−8．1

16．2

0

3．7
8．1
0

−9．3

16．2
9．3

−1．2

2．4
3．2

−6．9

2．4
0．8

0

℃

12．08
11．48
12．12
10．56
11．30
12．54
11．70
11．02
10．86
11．46
11．66
12．58
12．62
11．50
12．40
11．74
12．28
13．00
12．28
11．66
10．60
13．58
11．96
11．50
12．22
12．76
13．38
13．44
12．72

〟
×10kgm￣2a1

15．9
15．1
15．9
14．1
14．9
16．4
15．4
14．6
14．4
15．1
15．4
16．4
16．5
15．2
16．2
15．5
16．1
16．9
16．1
15．4
14．1
17．6
15．7
15．2
16．0
16．7
17．4
17．4
16．6

C

×10kgm￣2a「1

19．9
23．1
10．3
10．1
18．9
13．2
12．2
19．4
17．6
15．9
9．8
20．6
13．2
16．8
11．8
13．0
15．7
16．9
16．1
15．4
17．8
22．1
7．6
31．4
9．1
7．3
19．8
18．3
15．4

Glazirin et al，

7

4. Stabilizing feedbacks found in snow patches inJapanthe transectlineis anindicator of snow patch size．
Again，the greater the snow patch depthin autumn

4．エ肋（哲05乃0紬♪αわぁaccumulationinthefollowlngWinter．Thecorrelation（hencelarger snow patch）was，the smaller was the

In Fig・4，annualaccumulation，C，is plotted COefficient of the two variablesis −0．71，with theagainstcumulativespecific massbalance，Sb，Ofthe goodness−Of−fitofO．50．Sincethep−Valuefortheslope
precedingautumn，Whichiscorrelatedwellwithsnow
Ofthe regressionlineisless than O．001with signifi−
patchsize（notshown）．Thecorrelationcoefficientof
CanCelevelof5％，thenegativecorrelationofthetwo
the two variablesis −0．75．The slope and the
Variablesisstatisticallysignificant．
goodness−Of−fitoftheregressionlineare−0．67andO．
Sinceseasonalmassbalancevaluesforthissnow
56，reSpeCtively．Sincethep−Valuefortheslopeofthe
patch are available，We Were able to examine theregressionlineisO．087，thenegativecorrelationofthe
dependenceofablationonsnowpatchsizeinspring．

two variablesis statisticallysignificant with signlfi−Therelationshipbetweensummerablationandsnow

CanCeleveloflO％．Thisinverse relationindicates

thatannualspecificaccumulationbecomessmalleras
thesnowpatchbecomeslarger，aSpredictedfromthe
resultsobtainedbyGlazirin（1985）．
1

40patchdepthinspringisshowninFig．6．Thecorrela・
tioncoefficient ofthetwovariablesisO．55，Withthe
goodness−Of・fitofO．30．Sincethep−Valuefortheslope

OftheregressionlineislessthanO，01withsignificancelevelof5％，the correlation of the two variablesis

Statisticallysignificant．Itcanbeseenthatthelarger
the snow patch depths，the greateris the summer0㌔
1 2 0 0
N
．
∈
0 0 0
如
上 1
○
︻
X
．
b

ablation．

−200 0 200 400 （SOO 800
ふ♭，XlOkgm￣2a￣1
Fig．4．Dependenceofthespecificsnow accumulation of
Hisago snow patch（c）onits areain the preceding
autumn（A）．

12

16

J．エ／／・川仙〃〃●／、仙杵／一．ルソJ

Dependence of accumulation，C，On mean SnOW
patchdepth，Lhl，inthepreviousautumnforHamaguri
SnOWpatChisshowninFig．5．Sincenodescriptionof

snow density of the patch was found in reports on
Hamagurisnow patch，depth of the snow patch
insteadofsnowwaterequivalentwasusedforanaly−

Sis・Themeansnowpatchdepthoftheselectedpartof

20

24

／ね，m
Fig・6．Dependence of the snow ablation of Hamaguri
SnOWpatCh（a）onthesnowpatchdepthinspring（Hs）．

■J、ユんJな（J由∫JJ（）Jぐ♪（Jん、んThe relation between winter accumulation and

SnOWpatCh size （Smax）inthepreviousautumnfor
KaigatasnowpatchisshowninFig．7．Liketheother

25
20

㌔
†
∈
切
言
L
X
．
︒ 15

q ∈15
（〉

10
5
0

4

8

12

力b，m
Fig．5．Dependence of the snow accumulation of
Hamagurisnowpatch（c）onthemeansnowpatchdepth
intheprecedingautumn（Ih）．

5

10∫〝∂∬，XlOkgm

Fig．7．DependenceofthesnowaccumulationofKaigata
SnOWpatCh（c）onthemaximumsnowwaterequivalent
inautumn（Smar）．

βBulletinofGlaciologicalResearch

SnOWpatChes，thegreaterthe

size

is，thesmalleris

izdat，228pp．（in Russian）．
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Abe，M．，Nakamata，SリKoiwa，S．，Matsuoka，H．，I
two variablesis−0．63，Withthe goodness−Of−fit of O．
Sagisaka，S．，Watanabe，0．，Nakajima，C．，Inoue，J．an
40．Thep−Valueoftheslope ofregressionlineisless
Ageta，Y．（1979）：A summary on the studies of perenniaZ
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snowpatchesinJapan．Seppyo，41（3）181193．（inJapanese
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Inoue，M．and Matsuda，M．（1973）：Mass balance study ofthe
5．Summaryandfuturestudies
YukikabeperennialsnowpatchintheDaisetsuMountains，
Hokkaido．Seepyo，35（4）181191．（inJapanesewithEnglish

the accumulation．The correlation coefficient of theAnalysis ofdata on snow patchesinJapan con−firmedthatthereisastabilizingeffectonsnowpatch

abstract）．

Kawashima，K．（1997）：Formation processes ofice body
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Size．Whenthesizeofasnowpatchislarge（small）in
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autumn，SnOWaCCumulationinthefollowlngwinteris
Kawashima，K．，Yamada，T．andWakahama，G．（1993）：Investi−
Small（1arge）．Theeffectofsizeonablationrateislessgationsofinternalstructure andtransformationalproces−
Clear，butthedatasuggestthatablationisgreaterfor
ses from firn toicein a perennialsnow patch．Ann．oflarger snow patches．The specific causalfactors
Glaciol．，18，117−122．
Kodama，Y．andTakeuchi，Y．（1993）：Snowmeltandmeltwater
controlling the change in accumulation and ablation
runoffin an alpine basinI：Seasonalvariationin theasthesnowpatchsize changes are unknown．These
ablation of a perennialsnow patch，Low Temp．Sci．，Ser．
factorsshouldbeexaminedinfutureworksinorderto
Aリ52，25p38．（inJapanesewithEnglishabstract）．
developpredictivemodelsofsnowpatchchangeswith
Munro，D．S．and Young，G．J．（1982）：An operationalnet short−climate．
wave radiation modelfor glacier basins．Water Resour．
Resリ18（2）220230．
SnowpatchesinJapanmightbetheremnantsof
Ohata，T．，Yabuki，H．，Higuchi，K．，Watanabe，0．，Takena
pastglacialconditions，andtheir changes areimpor−Iida，H．and Takahara，H．（1993）ニ Variation of perennial
tant indicators of climatic variations．Whether
SnOWpatCh Hamaguri−yuki from1967to1991．Res．Rep．
COntinued globalwarming willovercome thelocal
OfIHAS，InstituteforHydrospheric−AtmosphericSciences，
Stabilizing effects，Which we have found，is unclear．
Nagoya Univ．，Nol，43pp．
Patersor】，W．S．B．（1994）：The physjcs of glaciers，3rd edition．
Globaユwarming can bring morewinter rainfalland
Pergamon，480p．
lesssnowfall．Continuedmonitoringoftheseperennial
Pertsiger，F．Ⅰ．（1984）：Long−term regime ofblowing snow type
SnOWpatChesiscriticalformaintainingourlong−termperennialsnow patch．Proceeding of CentralAsian
record of these features．The data record would be
Hydrometeorol．Res，Inst．（SANIGMI），117（198）117−123．

greatly enhanced by twice−yearly measurements sothat a seasonalcomponent can be deduced．Snow（in Russian）．

Shulz，Ⅴ．L．（1956）：ThawingofSnow Patchesin Mountainsof
CentralAsia．Tashkent．Publ．ofAcademyofSc．ofUzbek
patches other than snowdrift−fed snow patches anal−
SSR．351pp．（in Russian）．
yzedhere，SuCh as those that are fed by avalanches
Sosedov，I．S．andSeversky，1．Ⅴ．（1963）：Ontheroleofavalanche
andthoselocatedathigherandloweraltitudes，Should
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