Annals of C'laciologJ• 2 l 1995 © Interna ti ona l G laciological Society
lOOOyears of climatic change in China: ice-core 8180 evidence
P. N. LIN, L. G. THOi\lPSON, M. E. D AVI S and E. Mos LEY-THOi\ lPSO N Bj1rd Polar Research Center, The Ohio Stale Universi!J1, Columbus, OH 43210, C.S.A.
ABSTRACT. Since 1987, ice cores have been clri ll ecl from th e Duncle a nd Guli ya ice caps on th e Tibeta n Pl a teau, wes tern C hina . H ere, th e oxygen iso topi c (818 0 ) records for the las t 1000 years fr om both th ese cores a re compiled a nd compa red. Using surfa ce temperature obse rvati ons since the micl-l960s from meteorological sta ti ons on the pl a teau a nd 618 0 measured on precipita ti on coll ected contempor 18 18 a neously, the empirical rela tionship: 6 0 = 0.6 T,, - 12 is esta blished . 8 0 a ppears to serve as a reasona ble p roxy for regio na l surface te mperatures a nd a reasona bl e basis for reconstructing I 000 a proxy tempera ture records from Duncle a nd G uli ya. The reconstructed temperature histori es fo r Duncle (on the eastern Tibeta n Pl a teau) a nd Guliya (on the wes tern Tibeta n Pla teau) show so me centennial-scale simila rities, but reveal quite clifle rent histo ri es fo r hig her-frequency variability oYe r the last millennium. The ice-core 618 0 hi stories from Duncle a nd Guli ya a re co mpa red with a tree-ring index fi·o m western C hina and the dust-fall record from eastern C hina , hut show no consisten t rela ti onship. The m ost p rominent simila rity between the reconstructed temperature hi stori es for Dunde and Guliya is the ma rked 1-va rming of the last few d ecad es. From the l 000 a perspecti ve provid ed by these ice-core records, the recent warming on Duncle is unique in its streng th a nd persistence; however, th e warming on G uli ya (inferred from 18 0 enrichment) is more recent (since 1985) a nd no t unpreced ented . This recent warming over the Tibeta n Pla teau is evident in the Ii mi tee! meteorological records.
INTRODUCTION
In the las t d ecad e, ice cores have provid ed a Ya ri ety o f' unique pa leoclim a ti c hi sto ri es. For a n oven ·iew see Langway and O eschgcr ( 1989) and White and others (1989) . .1\I os t of these ha1·e centered on high-la titude ice co res such a: those li·om Greenland (e.g. D a nsgaard a nd others, 1969, 1982; Grootes a nd o thers, 1993 ), the Cana dia n A rc ti c (K oerne r a nd Fisher, 1990) a nd Anta rcti ca (Epstein a nd o thers, 1970; Lori us a nd others, 1979, 1985). T o complement these pola r hi stories a nd prO\·icl e furth er constraints upon mod el.· o f' global clima ti c 1·ari a ti ons, ice-core hi stori es from hi gh-elevati on ice caps in th e subtropics a nd tropics have begun to emerge. The fir st such history was fr o m the Quelccaya ice cap (13°56' S, 70°50' W; 5670 m a.s. 1. ) in Peru (Thompson and others, 1985, l 986, 1988) . M ore recently a record was obta ined fi·om the Dunde ice cap (38°06' N , 96°24' E; 5325 m a.s.1. ; Fig. I) in C hina (Thompson a nd o thers, 80E 90 100 110 120 1989; Thompson, 1992 ). Eastern C hina is ri ch in hi stori cal a nd d ocumenta ry Fig . 1. M a/J show i11g lite loca tion Qf D1111de and G' uliya ice so urces or clima te in fo rmation for the last millennium. ca/JS, China. ;\1I os t of the Chinese paleoclimatic reconstructions a re fr om regions east o f" l 10° E a nd fo cus upon conditio ns during winter, a lthoug h limited .- ummer histori es a re meteorological records (Bradley a nd J ones, 1993). emerging (Bradley a nd others, 1987). In western China , N evertheless, the clima te histo ry of wes tern C hina, proxy histori es (tree rings, ice cores) a re se1·e rely limited , pa rticul a rl y on th e Tibeta n Pla teau, is an importa nt and their w rification is ha mpered by the short a nd spa rse component for reconstructing a nd understa nding th e
189 Lin and others: Climatic change in China
Earth's climate history. The Tibetan Plateau, with an -5 average elevation of ~4500 m, is one of the Earth's most 1990 imposing geomorphic features and a ffec ts the large-scale -1 0 atmospheric circulation in th e Northern H emisphere (R eiter and Ding, 1980, 1981 ). T he extensive summer heating of the pla teau es tablishes and maintains th e Asian -15 \~t summer monsoon circula ti on (R eiter and Gao, 1982). I I I Thus, studies or th e climate regime or th e Tibetan Plateau I I I have fl ourished and th e potential for histories from -20 0 5 I I 10 15 20 25 30 western China has sparked th e interes t of" the paleocli I I I matic community. -5 Since 198 7, ice-core paleoclimate records have bee n ...--. 0 emerging fr om two ice caps on th e plateau: th e Duncle ice 0 -10 cap on th e northeastern side, and more recently the 0 ..__,-- Guliya ice cap (35°17'N, 81 °29'£; 67 10ma.s.1.) on the 0 00 northwes tern side (Fig. l ) where a glaciological program to -15 was co nducted fr om 1990 to 1992 . In 1990 one pit was sam pl eel and two cores were cl ri ll ecl: an 8 m core ( C- l ) -20 and a 12m core (C-2). In 199 1 one pit was sampled and 0 two cores were drilled: a 30 m core (C-1) and a 16 m co re -5 at th e summit core (SC-I ). In 1992 two d eeper ice cores we re recovered : a shorter core (C-1 ; 92 .3 m) at site l extended to an unco nformity (see Thompson and others, -10 1995); the longer core (C-2; 308.6m) reached bedrock at site 2. These cores are being a na lyzed for inso luble particulate co ncentrations and size distributions, ani on -15 2 18 (S0,1. , N03 , Cl ) concentrations, and 6 0. This paper focuses upon the similarities and differences of the Duncle -20 18 and Guliya 6 0 records for th e last 1000 a and compares 0 5 10 15 20 25 30 these proxy histori es with the limited data from western Depth (m) China and th e more abundant clima te histories from eastern and so uthern China. Fig. 2. The continuous isolo/Jic profiles for three cores drilled in successive JlecU"s ( 1990- 92) al the same site on the Guli)1a ice cap . Tlz e dashed lines indicate correlative DISCUSSION fea tures.
Figure 2 d emonstrates th e reproducibi lity of the 6 18 0 records in cores drilled at the same location on Guliya in good considering th e di stance and elevation differences three co nsec utive years (1990- 92 ). The 199 1 core was and other environmental factors w hi ch may affect 6 18 0. returned frozen while the 1990 and 1992 cores were cut, A ma rked warming trend since 1985 is evident in both th e melted and bottled for return shipment. The fi rst ice-core records and the station observations. It is clear constraint upon the paleoclimatic utility or 6 18 0 is the that 6 180 of the snow fa lling on Guliya provides a degree to \Nhi ch it reflects near-surface air temperature. reasona ble proxy for th e near-surface air tempera ture. To explore this, 6 180 was measured on precipitation The time-scales for the upper 380 a of th e Guliya and samples collected at the Delingha meteoro logical stati on Duncle cores were established by counting the visible dust so uth of the Duncle ice cap, and th ese were compared layers d epos ited a nnually. This allows the annual with contemporaneo us air tempera tures also measured at averages of dust content and 6 180 to be calcul a ted. For Delingha (Yao and Thompson, 1992). The empirical the old er part or th e Duncle cores th e time-scale is a rela ti onship between 6 18 0 and air temperature (Fig. 3a) model-based time- d epth relationship for th e combination derived from these da ta is give n by o[ cores 1 and 3 in which similar features were co nsidered coeval. Since it was impossible to co unt annual dust la yers down to the bottom of both Duncle cores, the fina l time scale is based on th e fl ow-model approach. In contrast, wh ere T., is air temperature. The 6 18 0 - temperature th e dating for the last 1000 years from the Guliya core-2 is coeffi cient or 0.6 is identical to that established for the based on co unting visible dust layers (see Thompso n and longer reco rds fr om other mid- and hi gh-l a ti tucl e regions oth ers ( 1995 ) for Guliya time-scale disc uss ion ). (e.g. R ozanski and others (1992) report a valu e of 0.6). Figure 4a and b ill ustrate the 1000 a 6 18 0 record fro m To test furth er how well 6 18 0 reflects air temperatures, Guliya co re-2 and the co mbined histori es fr om the Duncle th e annual averages of 6 180 for the three cores from site I deep cores (I and 3). A surprising res ult is the marked on Guliya (Fig. 2) are compared (Fig. 3b) with mean cli!Terence in the 6 18 0 histories fr om th ese two ice caps. annual air temperatures from i\!Iangnai meteorological The di!Terence in mean values (Duncle: - 10.88%0; Guliya: station (38 .2° N , 90.1 ° E; 3139ma.s.1. ). The agreement - 14. 77%0 ) is expected and consistent with the different between mean annual 6 18 0 and air temperatures is quite elevati ons or the drill sites (Dunde: 5325 m a.s.l. ; Guliya:
190 Lin and others : Climatic change in China
0 Delingha -8 18 • Dun de a 8 0=0.6T -12 ~ -9 -4 5 ., 0 ...... • ..._o 0 • 0~ -1 0 .._0 -8 •• • • 0 • ._... • • 0 -12 • CXl • !,o -12 -16 •
a -13'----'----'----'--.__---'---'---'-~'----'---' -20 1000 1200 1400 1600 1800 2000 -4 0 4 8 12 16 -11 Temperature (°C) Guliya b ~ -13 4 ..--.. 0 u Q _1 1 --c-ibmtTh~tt-it--tt-l-cf--'---'-l''ltl-'rl--ffi.tl'\!..,,flH 0 5 • Guliya ._...
191 Lin a11 d others: Climatic change i11 China
Fi gure 2 illustra tes tha t the three ice cores from Guliya Inferred (proxy) tempera tures sin ce 1500 (solid line: show consistent iso topi c pa tterns, suggesting tha t, a t the a ft er C hu, 1973) led Zha ng to suggest tha t cooler peri ods sa m e site a t least, the efTect or these locali zed factors is were associa ted with more dusty atmospheri c conditions, minor. The potentia l contribution or these factors to while dust flu x appears diminished when conditions a re differences on Guliya and Dunde is difficult to assess . warmer. The tra nsp orta ti on of dust fl·om n orthwest to southeas t C hina is related mainly to va ria ti o ns in atmospheri c circ ul a ti o n over m a inla nd C hina . In COMPARISON WITH OTHER DATA w inter, the strong Siberian hig h m oves south ward , leading the p ola r fronta l zone south as well. This Proxy hi sto ri es a re necessaril y imperfect represen tati ons enhances the stronger winter m onsoon a nd favors the or their surro undings because th ey a re limited by the entrainment a nd transport or dust during cold peri ods robustness or their time-scal e, their spa ti a l representative (Zha ng , 1984 ) . The dust is entra ined within the ness and the phys ical interpretation or the proxy itself. M ongoli a n cyclone, is tra nsported eastwa rd by the One or the few proxy records avail a bl e from western upper-level wes terli es a nd slowly settl es out over the C hina is a 935 a record or tree-ring widths in fo ur juniper eastern ha lf of C hina . In addition , m os t or the periods of trees covering the upper a nd lower limits or the fores t hi gh dust d ep ositio n appear to be associa ted with zone in the Qilia n Sha n region (W a ng and o th ers, 1983). conditions or lower humidity, indicating th a t dust storms Thinner rings a re interpreted as refl ec ting sub-o ptima l a re associa ted w ith the dry season (Zhang, 1984). growing conditions w hi ch could be cooler tempera tures, The dust history (Fi g. 4d ) from eastern C hina shows reduced precipita ti on or som e combina ti on. \Nang a nd no consistent rela ti onship with the Dunde a nd Guliya others ( 1983) interpreted thin ring widths as renecti ve or 8 18 0 records o\·e r the last I 000 a. The low li·cq uency or cooler tempera tures, a nd noted three prominent a nd/or dust storms li·om 1300 to 1450 AD is correla ti ve with prolonged cool peri od s a nd one less extensive event (Fig. iso topi call y warmer conditions on Guliya a nd cooler 4-c ). Cooler conditions las ting a bout 70 a a re centered on condi tions on Duncle. As with th e temperature compar 1480, 1690 and 18 10 whil e a shorter cool phase appears isons discussed a bove, the eastern C hina cl ust hi story much earli er in th e record , a round 1120. \!V a ng and a ppea rs m o re consistent w ith th e net accumula ti on others ( 1983) suggested th a l the three cold peri ods or the hi stories fr om G uli ya a nd Dunde (Tho mpso n and Ming- Qjng d yn as ty ( JLl. 28- 1865) corres pond to the so o thers, 1995 , fi gs 7 a nd 8). The peri od of· elevated dust call ed " Little l ee Age" in Euro pe, with th e m a in cold (eastern China) from 1150 to 1300 AD is associa ted with peri od a t 1725. reduced accumulatio n o n Guliya after which th e The m aj or occurrences or thinner tree rings a ppear to fi-equcncy or dust storms in the east d ro ps as accumula be associa ted qua li ta tively with m ore negati ve (cooler) ti on on Guliya in creases. In the m ore recent (better 8 1n0 intervals on Guliya, but show little corres pondence documented a nd el a ted ) pa rt or these records the peak in 111 to the Duncle 8 0 record . This is interes ting as the dust flux in about 1850 AD is correla ti ve w ith a peri od of junipers a re from ;::::3 000 m in the Qjlia n Sha n where the substantially lower net accumulation on both G uli ya a nd Duncle ice cap is located. A lso note fi·om the earli er Dunde. Likewise, the reducti on in dust-storm fi· equency discussion tha t the 8 18 0 histori es fro m Dundc a nd G uli ya since the turn or the 19 th century is associa ted with well arc dissimila r at times , with some longer-term cooler a nd a bove a verage net accumula tion on both ice caps. warmer inten -ct! s out or phase. These records suggest a ve ry complex rela ti onship T wo or the three " Ivling- Qjng-dynas ty" cool phases between the tempera tu re a nd preci pi ta ti on over th e (inferred fi·om limi ted tree-ring d a ta ) a ppea r in the 8 18 0 pl a teau a nd th e tempera ture and a tmos pheri c dustin ess history fi·orn G uli ya whi ch also suggests a persistence of over th e eastern ha lf or C hina . This preliminary inves ti ga cooler concli ti ons from 1800 to the mid-1 900s. Interest ti on sugges ts th a t net accumula ti on on the ice caps, rather in•rl ); th e most ]Jro! ono-ed cooli1w in the Guli )ra 8 180 th a n temperature, a ppears more closely rela ted to atmo t°) ' 0 i:) hi story is Crom about 1050 to 1200, contemporaneous wiLh spheri c conditions (temperature and dustin ess) in th e th e m arked ye t brier d ecline in ring widths. It should be eastern ha ir of C hina where proxy and histori cal climate noted that this earl y part or th e tree-ring record is based obse rvations a re more abundant. Also, fo r th e earli er part upon two trees, whi ch hi ghlig hts the spa ti a l limita ti on or or th e record (prior to 1500 AD) the lack or o bse rva ti ons th e d a ta . In fac t, th e tree-ring thi ckn esses appear to be (e.g. tree rings, dust fall ) a nd their imprecise time-scales more refl ec ti\·e or th e net accumula ti on hi stori es on the ma ke comparison with th e ice-corr histori es tenta ti ve at two ice caps (see Thompson a nd others, 1995, fi gs 7 and bes t. It is necessary to stress as well tha t 70- 80% of 8), but still with a stronger resembla nce to the Guliya precipita ti on on th e ice caps [a ll s during the summer history. Previous im·es ti gations or tree-ring records from monsoon season so th a t the 8 1HO hi story proba bl y refl ects lower-elevati on ( < 3500 m ) sites in Tibet (Wu, 1992) summer conditions m ore strongly tha n a nnua ll y averaged have indicated that ring widths in this dry region a re conditions, and tha t a t these hi gh elevati ons there is a m ore ren ec ti ve o r prec ipita ti o n \·ariatio ns th a n o r potential for sublima ti on ( 18 0 enrichment) during the dry temperature vari a ti ons. The ice-core d a ta would tend to pa rt of th e year. T hus, 8 18 0 measurements a re predes tined support this idea. to be imperfect representatio ns or n ear-surface air Figure 4·d presents a hi story or the fr equency or cl ust te mpera tures . i\lluch or the dust depos iti on on th e ice f ~t!I (cl ashed line) for a n a rea fr om Xinjia1w to the east caps (and over eastern C hina as well ) is associa ted with the coast or China and fr om Nei Mongol to th e south or the dry winter monsoon season so th a t dust flu x is likely to be Ya ng tze Ri\·e r (Zha ng, 1 98 '~ ) , a n a rea consistent with the more representa ti ve or a tmos pheri c conditions in winter loess distribution in C hina (Liu a nd o thers, 198 1 ). than o [ a nnuall y averaged conditions.
192 Lin and others: Clima tic change in Cltina
T he more recent part of th e ice-core 818 0 records is Ya ngtze River. Summer a ir tempera tu res f! ·o m so u th compared with surface temperature observations in eastern C hina (Fig. 6b) and from th e 10\·ver Yangtze Figure S. The Sa running mean of th e annua l 8180 River (Fig. 6c) have been reconstructed for the las t fi ve \ alu es fr om l 8SO to 1992 from G uli ya and Dunde (both centuri es. T he cold est period, the m id -1 7th century elated to 18SO by layer counting ) is shown in Figure Sa (around l 6SO AD ), is prominent in a ll records. The and b. As noted earli er, isotopicall y warm and cold normalized mean summer temperatures (F ig. 6cl ) and peri ods are not synchronous for Duncle a nd Guliya, a nd th e normalized mean winter temperatures (Fi g. 6e) also this is particularly true for a nnua l and cl ecacl a l-scale data. indicate cooler conditions around 18S01'D. Note tha t th e Howe,·e r, both records reveal a persistence of higher 8180 818 0 records in F ig ure 6 a re shown with res pec t to thei r values (warmer temperatures) sin ce th e 1940s, simila r to ( l 860- l 9S9) means for consistency with th e o th er cl a ta th e warn1ing in th e Northern H emisphere land-surface (Fig. 6b- e). The Duncle 818 0 hi story is much more tempera tures since the 1920s (Fig. Sc ) and the India n similar to the temperature hi stor y in so utheastern Chin a O cean surlace temperatures (Fig. Sci ). T he 818 0 da ta than is the Guli ya 818 0 hi story. T he most prominent from G uli ya a nd Dunde a lso corres pond reasona bl y well clima te event in a ll th e records (8180 , tree ring, dust fa ll) with th e temperature record from th e Indian O cean is th e cool period around l 6SO AD which appears to ha,·e (Briffa a nd J ones, 1993), which is encouraging as th e affected both eastern a nd western C hina . Another precipitation reaching th e western part of the Tibetan Plateau o rigina tes primarily over th e Indian O cean during the summer monsoon season (Luo and Yanai, -5 a 1983, 1984- ). 0 Dun de 0 o-. -1 Om=""""=""""' """="""==""""~"""'rL--'-=1 -8 -0 a "' -9 ~VO -1 5 1::::--+*--\..,,="'-.>J.--ll-l~f-C>.'-'---\,,./+.+W-'__.j~
-10 -11 -20'--.1-.1-.1...... _.__.__._--'-..... ,...... , 0 -12 2 0 0 -13 0~-L~'--\,,~f>=""""'=r''-"""'~~d--~ '-" -- 1860 1880 1900 1920 1940 1960 1980 2000 -2 0 _i,_..i...._, tO -10 0 -4 ._...... _ __._..__._...... Guliya b c. ~"° -12 (/) Q,) '- -14 :::l t ro -16 a. Q,) China d 0 -18 2 1860 1880 1900 1920 1940 1960 1980 2000 0 t=%'1ef-~~~==='~fZ'rl~---'>...-j
x Year (A.O.) Fig . 6. Decadcil averages q/ 8111 0 .fiom a. Dunde and Guli)1a are com/Jared with available lem/Jernlure records Fig. 5. The 5 a running mean of 8111 0 from 1850 lo 1992 from other areas q/ Chi11a. All data are slww 11 relative to .fiom a. Dunde and b. Guli)'a ice ca/Js is com/Hn -ecl with two th eir res/Jecti ve 1860- 1959 means. b. Summer /em/Jeralure other tem/Jeratu re histories: c. Northern 1-/emis/Jhere variati011s in southeast Chi11a are Ji-om I l'a11g and others temperature variations ( Hansell and Lebedeff, 1987) and ( 1991 ). c. Summer tem/Jeralure a1wmalies for the lower d. lndia11 Ocean swface /em/Jera/ure data ( Briffa and rangtze River are from Wang and f. Vang ( zm/J1lblished Jones, 1993) . infornwlion, 1992) and Bradlq rmd J ones (1993) . d. J\!lean. normalized summer lemjJera luresfor easlem China are from Wang and l!Jl a11g ( 1990 ); Wang ( 1991 ); and Lo nger temperature histories a re available [i·om f'llang and others ( 1991 ) . e. J\lf ean normalized winier so uthern a nd eastern China. H ere " i\lfei Yu" or plum lem/J era lures for east em China are .fiom Z hang and Gong rains are a main so urce of precipitation, dominant in ( 1979); Zhang ( 1980); Wang and Wa11g ( 1990); spring and summer, over most of C hina so uth ol the !Vang (1991 ); and TVang and others ( 1991 ) . 193 /,in and others: Clima tic change in China important feature in 1000 a 8 180 records from Dunde a nd REFERENCES Guliya is a warming trend in the 20th century. Although not as prominent in th e decacl a ll y averaged d ata from BradlcY, R . S. a nd P. D. J o nes. 1993 ... L in le Ice Age' · summer Guli ya, since 1985 it is una mbiguously a n " iso topicall y" tempera ture va ri a ti ons: th eir na ture a nd relevance to recent global 11·arm ing trends. H11/11w1e , 3 (4 ), 367- 376. warm feature in both summer a nd winter (i.e. the hi ghes t Bradley, R. S. , H . F. Diaz, P. D . J ones a nd P. i\ I. Kell y. 1987. Secula r 18 a nd lowest 8 0 values) for a ll three cores (Fig. 2). fluc tuat ions or temperature O\·er Northern Hemi sphere land a reas a nd ma inla nd C hi na sin ce the mid- 19th centu r)'· In Ye, D. H., C.B. Fu , J.P. C hao and i\·I. Yos hino, eds. Th e climnle of China and global dimaif. Berlin, Springer- Verlag, 76- 87. CONCLUSIONS Brill>1. K . R. a nd P. D. J ones. 1993. G lobal surface air temperature \·ariations during th e t\\'Cntieth ce ntury: Part 2. Im pli ca ti ons for largc The 1000 a 8 1a0 records from the Duncle a nd G uli ya ice scalc hi gh-rrequcncy palaeocl ima ti c studies. Holoc1me, 3 ( I ), 77 - 88. caps on the Tibeta n Pla teau, western China, display C hu, K. 1973. A preliminary stud y on the cl imate nuctuations d uring the last 5000 years in C hina . Sri. Sin., 16(2), 168- 189. different climatic vari a ti ons whi ch m ay reOect their Dansgaard, \\' .. S. J . J ohnsen, J. i\ loll er and C. C. Langway, .J r. 1969. cl ifferen t moisture so urces. Al ti tucl e clifieren ces on!y a ffect One th ousa nd centuries or· cl im a ti c record fi·om Camp Cent ury on 8 1HO mean ,·alues, a nd d a ting errors a re unlikely to the Greenland ice shee t. Science, 166(3903). 377- 38 1. 18 Dansgaard. \\".and 6 oth ers. 1982. A new G reenl a nd deep ice core. Science, co ntribute strongly to the obsen·ecl d ifferences. The 8 0 218(4579), 1273- 1277. measurements of snow coll ected on Gu li ya refl ect air Epstein , S .. R. P. Sharp and A . .J . Gow. 1970 . . \ntarctic ice sheet: sta bl e temperature trends a t Mangnai meteorological sta ti on, iso tope a na lyses or Byrd Statio n cores a nd interhemispheri c climatic suggesting that 8 1BO of the snow fa lling on G uli ya implications. SrimCI' , 168(3939), 1570 l:-i72. provides a reasona ble proxy for the near-surface air Grootes. P. i\'I. , i\ I. S tui ver, J . \\I. C. \\"h itc , S . .Johnse n and .J. J ouzel. 1993. Compariso n or oxygen iso tope record .s fi·n m the G IS P2 and tern perature. G RIP Greenl and ice cores .. \ ·a lure, 366(64·5.'> ), 552- 5.'>4. 1 T he ice-core 8 a0 histories from Duncle a nd G uli ya H ansen. J . a nd S. Lebed eff. 1987. G lobal trends or measured surface air a re compa red with a tree-ring index from wes tern C hina te mpera ture. ]. C:1'0/1hp. Res .. 92(D l I), 13,345- 13,372. and th e dust-fa ll record lrom eastern China, but show no Koerner, R . i\ l . a nd D. A. Fisher. 1990. A record or H olocene summer cl imate fi·o m a Canad ia n hi gh-Arcti c ice core. Aature, 343(6259), consistent relationship. Interes tingly, the net accumula 630- 631. tion histori es fi-o m Dunde a nd Guli ya a ppear to be more Lang11·ay , C. C., J r and H . Oesc hger. 1989. Introduction. In O eschger, consistently related to each other a nd with dust fa ll in H . and C. C. Langway, .Jr, eds. Th1' e111·iron111mtal record in glariers and ia eastern China . Large-scale trends in the 8 18 0 hi story [i-o m sheets. C hi ches ter, etc., J ohn Wiley a nd Sons, 1- 11. Liu , T S. , >; . F. Gu .. Z. S. An and Y. );_ Fa n. 198 1. T he dust fo ll in D unde a re more simila r to those in eastern C hi na tha n Beijing, Chi na on April 18, 1980. C:eol. Soc. Am . .Sjm-. Pa/J. 186, 149- 157. are the trends from the Guli ya ice cap fa r to the west. Lo ri us, C ., L. .\lcrli,-,11 , .J. J ouzcl a nd .\I. Pourehet. 1979. r\ 30,000-yr Both ice-core histories a nd th e oth er limited proxy records iso tope cl imatic record fi ·om Antarcti c ice . . \ "a ture, 280(572'>), 644- 64-8. Lorius, C. and 6 others. 1985. A 150,000-\-car cl imatic record li·om suggest a widespread cool peri od around 1650 i\D. The Ant a rctic ice . . \"aturi•, 316(6029), 591 - 596. Guli ya hi story contains a major cool phase around Luo, H . a nd i\ I. Yanai. 1983. The large-scale ci rcula tio n a nd heat 1500 AD, but th is docs not a ppear to have extended to sources o\·cr th e T ibetan Plateau and surro unding areas during th e the east. Finally, a most im portant observation is th e early summer or 1979. Pa rt l: Prec ipitation and kinema tic anah-sis. recent warming refl ected in the records from both ice ,I/ on . Weather Rm , Ill, 922- 944. Luo, H . a nd ~vi. Yanai. 1984. The large-scale circ ula tion and heat caps. The warming appears to have begun severa l sources o,·cr the Tibeta n Plateau and surro unding areas during th e decades earli er on the lower-ele,·ation Dunde ice cap earl y summer or 1979. Part 11 : Heat a nd moisture budgets. i\1 011. and more recently, since 1985, on the hi gher Guliya ice I 1·eath1 •r Rn •., 112, 966- 989. cap to the west. The older pa rts or the G uli ya core a re Oha ta, T., S. Takahashi and X. K ang. 1989. i\ letcorological conditions or the west Kunlun mountains in the summer or 1987. Bnl/. ClaciN currently bei ng analyzed a nd along with th e contem Res ., 7, 67- 76. pora neous hi story [)-o m Dunde should provide a proxy Qian, Y. , H . Vian, Q \V ang a nd A. \V a ng. 1!)88. "l umeri cal studies or record, partic ul a rl y as transfer fun cti ons between 8 180 topography effect on pl a netarv atmosphere. lu Sriena l~\fJress . [In a nd tempera ture a nd the rela ti onship between tempera Chinesc.J Rei ter, E. R. and Y. 1-1. Ding. 1980. T he role or the Qing ha i Xizang ture a nd precipitation a re better es ta blished . Plateau in fCe dback mechanisms affecting the pl a netan · circulation. Scimtia .- 1/11111,phnirn Sinirn , 4 (4 ), 301 - 309. Reiter. E. R. a nd Y. H . Ding. 1981. The role of the Qingha i- X izang ACKNOWLEDGEMENTS Pl a teau in feedback mecha nisms aflccring the pla netary circula ti on. Scientia :ltmosj1herica Sinira , 5 ( I ). 9- 22. R eit er, E. R . a nd D. Y. Gao. 1982. Heating or the T ibetan Pl ateau and This research was supported by th e U.S. Nati onal Science 111 0\Tlll ents or the sou th Asian high d uring sp ring. ,\Jon. IJ"eathn Rer. , Founda ti on's Office of Climate D yna mi cs a nd the 110, 1694- 1711. Di vision of Polar Programs (ATTvI-85 19794, ATM- Roza nski , K ., L. Araguas-f\raguas and R. Confiantini. 1992. Rela ti on bet 11·ecn long-te rm trends or oxygen-18 isotope compos iti on or 89 11 6635, DPP-90 1493 1), the Nationa l Geogra phical precipitation a nd climate. Srimre. 248. 98 1- 985. Society (3323-86, 4309-90 a nd 4522-9 1) , T he Ohio State T ao. S. Y. and Y.1-1. Ding. 198 1. O bse rn11ional e,·id ence of the infl uence University a nd the Natural Science Foundation of C hina. or th e Qinghai- Xizang (T ibet) Plateau on the occurrence or !J ca,·y \Ve th a nk researchers a t the La nzhou Institute of rain and se,·e1-c com·ecti \T storms in C hina. /311//. Am . . kfrteorol. Soc. , 62. 23- 30. G laciology a nd Geocryology fo r their efforts. v\le Thompson. L. G. 1992. Ice core e,·idence fi·orn Peru and C hina. In ackn owledge the supreme efforts of a ll th ose pa rticipa t Bradley, R. S. and P. D. J ones , ed.\'. Climall' since .- 1.D. 1500. London, ing in the fi eld program . Comments by M. Nakawo a nd Routl edge. 5 17- 548. Thompso n, L. G., E. ~lo s l ey -Th ompso n , J . F. Bolzan ;rnd B. R . Koci. two a nonym ous reviewers substantia ll y imprm·ecl th e 1985. A 1500-vear record or tropical preci pita ti on in ice cores fro m manuscript a nd are sincerely a ppreciated . This is the Quelccaya ice cap, Peru . ScienCI', 229(4./ 17), 97 1- 973. contribution No. 923 or Byrd Polar R esearch Center, Thompson, L. G .. E. ivloslcy-Thom pso n, \\'. Da nsgaard a nd P. M. The Ohio Sta te U ni,·e rsity. Grootcs. 1986. T he Li tt le Ice Age as record ed in the stratigraphy or 194 Lin and others: Climatic ch ange in China the tropical QuelccaYa ice cap. Scienre, 234(4774). 361- 364. relationships between tree rings or Qjlianshan juniper and cl imatic Thornpson. L. G .. l\ l. E. Dm·is. E. l\'l oslev-T hornpson a nd K-b . Liu . change a nd g lacial aCLi\·ity during th e past 1000 years in China. 1988. Pre-lncan agricultural acrh·ity record ed in dust layers in l \\"O k ex11 c Tongbao , 28( 12), 1647- 1652. tropical ice cores . . \ (1t11rc, 336(620 1) . 763- 765. \\"hi tc, J. \\". C. and 11 others. 1989. Group report : Ho"" do glaciers record T horn pson, L. G. aud .9 othN.1. 1989. Holocene- L lle Pleistocene cl irna ti c cm·ironrncntal processes a nd presen-c in fo rmation' / 11 Oeschgcr, H . ice core records frorn Q ingha i- T ibetan Pl a teau. Srienre, 246 ('1·929), and C. C. Langway, Jr. ('{/s. Tiu e11 viro11me11lnl record in glacins and ice 4-74- +77 . sheets. C hic hes ter, etc. , J ohn \\"ilcy a nd Sons, 85- 98. Thornpson, L. G. and .9 others. 1990. G lacial stage ice-core records frorn Wu, X. D. 1992. D endrocl irn a tic studies in C hina. In Bra dley, R . S. a nd the subtropical Dunck ice core . .'11111. G'lariol. , 14, 288- 297. P. D . J ones , eds. Climate since A. D . 1500. London, R outledge, 432- 445. Thornpson, L. G. a11d 6 others. 1995. A I 000 year cl irna ti c ice-core record Yao, T. a nd L. G. T hompson. 1992. Trends a nd !Cat urcs or cl imati c fi·orn the G uli va ice cap, C hina: it s rela ti onshi p to global climate changes in the past 5000 years record ed by the Dunde ice core . .'11111. rnri abili ty. A1111. Clariol .. 21 (sec paper in this ,·olurne). Glacial .. 16. 2 1- 24. \\"ang, R ., S. \\"a ng and K . F raedrich. 199 1. A n app roach to Y ch, T . C. 198 1. Some characteristics of the summer circulation m-cr th e reconstruction o f' rcmpcrat urc on a seasonal basis using his tori ca l Qjngha i- Xizang (Tibet) Plateau a nd its neighborhood. Bull . .'1111 . documents from C hina. /11ten111tio11al ]011mal ~/Cli111atologr , 11 , 38 1- 392. .\ll'ieorol. Soc., 62, 14- 19. \\"ang, S. 199 1. R econstruction o f" pa la eo-tcrnpcrature series in C hi na Zha ng, D . 1980. \\'inter temperature changes d uring the last 500 years f"rorn the 1380s to the 1980s. 11"1ir.;;b. C1'ogr. 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