Preliminary results from the chemical records of an 80.4 m ice core recovered from East Rongbuk...

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Earth Science Faculty Scholarship Earth Sciences

1-1-2002

Preliminary Results from the Chemical Records ofan 804 M Ice Core Recovered from East RongbukGlacier Qomolangma (Mount Everest) HimalayaQin Dahe

Hou Shugui

Zhang Dongqi

Ren Jiawen

Shichang Kang

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Repository CitationDahe Qin Shugui Hou Dongqi Zhang Jiawen Ren Kang Shichang Mayewski Paul Andrew and Wake Cameron P PreliminaryResults from the Chemical Records of an 804 M Ice Core Recovered from East Rongbuk Glacier Qomolangma (Mount Everest)Himalaya (2002) Earth Science Faculty Scholarship Paper 138httpdigitalcommonslibraryumaineeduers_facpub138

AuthorsQin Dahe Hou Shugui Zhang Dongqi Ren Jiawen Shichang Kang Paul Andrew Mayewski and Cameron PWake

This conference proceeding is available at DigitalCommonsUMaine httpdigitalcommonslibraryumaineeduers_facpub138

Preliminary results from the chemical records of an 804 mice core recovered from East Rongbuk Glacier

Qomolangma (Mount Everest) Himalaya

QIN Dahe1 HOU Shugui1 ZHANG Dongqi1 REN Jiawen1 KANG Shichang1 2

Paul A MAYEWSKI2 Cameron PWAKE3

1Laboratory of Ice Core and Cold Regions Environment Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Lanzhou 730000 China

E-mail dhqinrosecashqaccn2Institute for Quaternary and Climate Studies University of Maine Orono ME 04469 USA

3Climate Change Research Center Institute for the Study of Earth Oceans and Space University of New Hampshire Durham NH 03824 USA

ABSTRACT High-resolution chemical records from an 804 m ice core from thecentral Himalaya demonstrate climatic and environmental changes since 1844 Thechronological net accumulation series shows a sharp decrease from the mid-1950s whichis coincident with the widely observed glacier retreat A negative correlation is foundbetween the ice-core d18O record and the monsoon precipitation for Indian region 7The temporal variation of the terrestrial ions (Ca2+ and Mg2+) is controlled by both themonsoon precipitation for Indian regions 37 and 8 located directly south and west of theHimalaya and the dust-storm duration and frequency in the northern arid regions suchas theTaklimakan desert ChinaThe NH4

+ profile is fairly flat until the 1940s then sub-stantially increases until the end of the1980s with a slight decrease during the1990s whichmay reflect new agricultural practices The SO4

2^ and NO3^ profiles show an apparent

increasing trend especially during the period1940s^80sMoreover SO42^ concentrations

for the East Rongbuk Glacier core are roughly double that of the nearby Dasuopu core atXixabangma Himalaya due to local human activity including that of climbing teamswho use gasoline for cooking energy and transport

1 INTRODUCTION

Due to the large population of Southeast Asia and its vulner-ability to droughts and floods a better understanding of thevariability associated with the southwest monsoon would beimmensely beneficial However relatively little is knownaboutclimatic changes in the region over time- scales ranging fromcenturies to thousands of years The Himalayan region con-tains many subtropical high-elevation glaciers where ice-corerecords with high resolution can be collected (Mayewski andothers 1984 Hou and others 1999 Qin and others 2000Thompson and others 2000) Moreover the Himalayan rangeacts as aboundarydue to its highelevation limiting the north-ern extent of the Indian summer monsoon Ice-core recordsfrom such sites could therefore provide insight into variationsof the monsoon in the past as well as the background know-ledge necessary to identify temporal and spatial variations inthe linkagesbetweenvariousclimate systems in Asia helpful indetermining controls on climate change in this region

In August 1998 an 804 m ice core was recovered from asite at 6500masl on East Rongbuk (ER) Glacier lt5 kmnortheast of the peak of Qomolangma (Mount Everest) (Fig1) Here we present a discussion of the climatological andenvironmental significance of the chemical records of the ERcore

2 METHODOLOGY

Standard methods were used for ice-core sampling (Buck andothers1992Whitlow and others1992) To avoid possible con-tamination strict protocol was followed during processingAll sampling tools and sample containers were pre-cleanedusing ultrapure water During sampling personnel involvedwore polyethylene gloves non-particulating clean suits andmasks Samples were kept frozen (in the field and duringtransportation) until analysis In addition blanks were ana-lyzed at the beginning middle andend of each processing day

The ice core was cut at intervals of 35^5 cm for a total of1816 samples For each of the samples an outer 2 cm annuluswas removed and the inner sections were immediately putinto pre-cleaned plastic sample containers for further chemi-cal analysis At the same time the scraped ice material wascollected for shy -activity measurement Each of the shy -activitysamples weighed about 1kg corresponding to a length of110 cm ice core

Analyses of oxygen isotope ratios (d18O) were performedin the Laboratory of Ice Core and Cold Regions Environ-ment Chinese Academy of Sciences using a Finnigan delta-plus mass spectrometer (accuracy 005) and results areexpressed as the relative deviation of heavy-isotope contentof Standard Mean OceanWater Measurements of the major

Annals of Glaciology 35 2002 International Glaciological Society

278

chemical species were performed using a Dionex model 4000ion chromatography system and the shy -activity samples werefiltered twice through cation exchange filters and analyzedwith a gas-flow proportional counter at the Climate ChangeResearch Center University of New Hampshire

Snow and ice chemistry in the Himalaya shows a clearseasonal variation that can be used for ice-core dating Basedon the deuterium content of precipitation samples collected atLhajung (4420m) Nepal Himalaya from April 1974 toMarch 1975 Wushiki (1977) found high dD values in the pre-monsoon precipitation and lowest values in the middle of themonsoon season which are believed to be due to a ` precipita-tion-amount effectrsquorsquo This style of seasonal variation of stable-isotopic content in precipitation is also apparent on the northslope of the Himalaya (Wake and Stievenard1995 Kang andothers 2000) High concentrations of Ca2+ Mg2+ and SO4

2^

in the springsummer season suggest that dust raised duringthe spring dust-storm period is transported southward fromtheTaklimakan desert and the Qaidam basin China by per-sistent northwesterly surface winds (Wake and others 1993Kang and others 2000) The summertime peaks of Na+ andCl^ ions reflect the influx of marine air masses associated withnortherly-flowing monsooncirculation (Wake andothers1993Kang and others 2000) Therefore internal consistency existsbetween the seasonal variations of stable-isotopic ratios andmajor-ion concentrations for our ice-core chemical recordsie high d18Ovalues roughlycorrespondto the major-ionpeaks

We first use the annual signal in the d18O series to datethe ice coreWhen the d18O data do not provide a clear sea-sonal cycle seasonal variations in major-ion (Ca2+ Na+

and NH4+) profiles are utilized The dating is further veri-

fied by shy -activity peaks corresponding to the annual layers1963 and1954 (Hou and others 2002 fig2) and the sulphatevolcanic events of 1877 (Suwanose-jima Japan 295sup3N1297sup3 E) 1883 (Krakatau Indonesia 61sup3 S 1054sup3 E) 1888

Fig 1 Location map of ice-core drilling sites in the centralHimalaya

Fig 2The net accumulation profiles of the ice cores collected at ER Glacier (a) and FER Glacier (b) together with the all-Indiasummer monsoonal precipitation record (c) and the all-India annual precipitation record (d)The coarse lines show the four-pointsmoothing results

279

Qin and others Chemical records from East Rongbuk Glacier

(Bandai Japan 376sup3 N 1401sup3 E) 1889 (Suwanose-jimaJapan 295sup3 N 1297sup3 E) 1902 (three eruptions at 13^15sup3 N)1929 (Komaga-take Japan 421sup3 N 1407sup3 E) 1951 (twoeruptions at 89^163sup3 S) and 1963 (Agung Indonesia83sup3 S 1155sup3 E) However it should be noted that some sul-phate peaks in our core can be formed by springsummerdust storms It is also suggested that a major monsoon fail-ure the cause of a devastating Indian drought occurred in1876^77 (Thompson and others 2000) which correspondsto the peak concentrations of marine ions so we set thehighest Na+ concentration at 635 m as a reference of 1876

3 RESULTS AND DISCUSSION

31 Decline in recent net accumulation

We calculate the chronological series of the annual netaccumulation since 1954 (Fig 2) based on the dating andthe density^depth profile (we measured the density of eachice-core drilling interval and a total of 190 measurementswere obtained) The results of another core recovered froma site at 6500 m asl on Far East Rongbuk (FER) Glacier in1997 (Hou and others1999) are compared here Four-pointsmoothing is adopted to eliminate the stochastic effect ofdating The net accumulation records of the ER core (Fig2a) and the FER core (Fig 2b) clearly show a sharp declinefrom the mid-1950s to the late1960s and fairly steady valuessince then The average annual net accumulation values forthe two periods1954^63 and either1964^96 (FER) or1964^97 (ER) as identified by the double shy -activity peaks are5817 mm and 3212 mm we for the ER core and 2675 mmand 1503 mm we for the FER core respectively The netaccumulation ratios between the above periods are alsovery similar for the ER core (181) and the FER core (178)The thickness and strain rate are not yet available so thethinning effect cannot be adjusted Since more thinning isexpected in deeper annual layers the real decrease inamplitude from the mid-1950s to the late 1960s would bemore prominent after a thinning adjustment

The average net accumulation rate at the FER core siteis less than half of the corresponding value at the ER coresite though these two sites are only a few kilometers apartThe effect of orography is believed to account for the lowaccumulation rates at the FER site since an east^west ridgeover 7000 m asl separates FER and ER Glaciers Most ofthe annual precipitation received in the Himalaya origi-nates from the Bay of Bengal and the Arabian Sea duringthe summer monsoon season It penetrates through a rela-tively low col and deposits at the ER core site resulting inrelatively high accumulation rates there Moreover FERGlacier is located on the south slope while ER Glacier ison the northern slope Therefore heavy snowmelting takesplace on the surface of the FER Glacier as observed in thefield but little if any melting occurs at the ER core siteduring the ablation season which enhances the differencebetween the net accumulation rates at the two drilling sites

We previously speculated that the decreased net accumu-lation at the FER site is associated with a recent temperatureincrease in the region that intensified the ablation (Hou andothers1999) Qin and others (2000) also suggested a decreasein moisture fluxassociatedwitha change in atmospheric circu-lation Here we compare the net accumulations with the all-India summer monsoonal and annual precipitation records(Fig 2c and d respectively data are available from Indian

Institute for Tropical Meteorology at httpwwwtropmeternetin) The substantially decreased rainfall amounts fromthe mid-1950s to the late1960s are consistent with our ice-corerecords Subbaramayya and Naidu (1992) also suggested asudden decrease in the all-India monsoon rainfall during1958^69 from the 11year moving averages of the area-weighted average monsoon rainfall in all the subdivisions ofIndia Thus it appears that a sudden climate change in theAsian monsoon regionwith respect to the total monsoonrain-fall occurred from the late 1950s to the late 1960s leading togeneral drought conditions through the complex interactionsamong monsoon rainfall Himalayan and Eurasian snowcover sea-surface temperature and wind field While thedecreasing rainfall trend was reversed in the early 1970s (Fig2c and d) it has continued in parts of central north India thatare adjacent to our drilling sites (Subbaramayya and Naidu1992) This is also true of the high Himalaya as indicated bythe continuing low net accumulation rates from the 1960s tothe present (Hou and others1999 Qin and others 2000)

Though model studies mostly suggest an increase in mon-soon precipitation with greenhouse-gas-induced global tem-perature increase as a result of intensification of monsooncirculation due to increase in landôcean thermal contrastdecreased monsoon precipitation was also predicted basedon sulfate aerosol forcing (Lal and others 1995 Mudur1995) Thus the decrease in net accumulation may also bedue to the location of the ice-core drilling sites between twolarge emission sources ie China and IndiaThe ER ice corealso shows a one-third increase in sulfate concentration sincethe beginning of the 20th century (see below) It is likely thatthe increase in atmospheric sulfate aerosol has already begunto affect the monsoon in the Himalaya offsetting the increas-ing trend in monsoon precipitation that would have beencaused by the increase in atmospheric greenhouse gases(Shrestha and others1997)

32 d18O

The d18O record of the ER core is negativelycorrelated withthe monsoon precipitation for Indian region 7 (R = 0206)and the correlation coefficient increases to ^0323 for theperiod 1954^97 when the dating result is more reliable dueto the shy -activity horizon (Fig 3) Qin and others (2000) alsosuggested that atmospheric circulation is strongly associ-ated with d18O in the Himalaya However Thompson andothers (2000) hypothesized that temperature is the domi-nant process controlling d18O in the Dasuopu ice core

In the tropics a strong inverse relationship is recognizedto exist between the d18O in precipitation and the amount ofprecipitation (Dansgaard1964 Rozanski and others1992) Insouthern regions of the Qinghai^Xizang (Tibetan) Plateauand the Himalaya the amount effect on d18O in precipitationis also evident based on the results from precipitation andsnow-pit sampling (Wushiki 1977 Wake and Stievenard1995 Kang and others 2000 Qin and others 2000) There-fore the inverse association between ER d18O and precipita-tion in Indian region 7 is to be expected giventhe influence ofprecipitation amount on d18O Previous studies have also sug-gested the influence of local moisture transport to FERGlacier (only a few kilometers from ER Glacier) which hasundergone less isotopic fractionation (Qin and others 2000)

The ER FER and Dasuopu cores were all dated by thereference layers of shy -activity peaks and similar samplingand analysis methods were adopted for the isotopic measure-


280

Fig 3The d18O profile of the ER cores together with the summer monsoonal precipitation record for Indian region 7The dashedlines show the annual means and the solid lines show the 3 year smoothing results

Fig 4Three-year smoothing results of the annual Ca2+and Mg2+averages of the ER cores and the annual monsoon precipitationrecords for Indian regions 7 and 8The coarse lines for Ca2+ Mg2+and precipitation profiles show the polynomial regressions toindicate their corresponding long-term variations Annual dust-storm history at Minfeng is from Shalamaiti (1996)The originalionic concentrations were resampled to yield average annual values in order to match with the other annual data and a 3 yearsmoothing mean was applied to eliminate the stochastic effect of dating error

281


ment so we believe that the d18O profiles of the two coresreflect their corresponding climatic signals The apparentdiscrepancy between the d18O profiles shows the difficulty ofaccurately interpreting ice-core records from the Himalayaand more cores are needed to deduce the spatial characteris-tics of the ice-core records

33 Ca2+ and Mg2+

In Figure 4 we plot the Ca2+ and Mg2+ profiles of the ERcore together with the monsoon (June^September) precipi-tation for Indian regions 7 and 8 and the annual dust-stormduration and days at Minfeng located on the southern edgeof the Taklimakan desert (Shalamaiti 1996) A negativerelation is found between the crustal-source Ca2+ and Mg2+

and the monsoon precipitation The correlation coefficientsare ^0141 between the annual Ca2+ values and their corres-ponding regional monsoon precipitation and 0244 for the3 year unweighted running means respectivelyThe negativerelationship still exists at decadal scale as indicated by thepolynomial regressions The agreement between the Ca2+

and Mg2+ variations and the dust-storm records for theperiod 1960^90 indicates the potential influence of the aridregions on the ice-core Ca2+ and Mg2+ records Though anegative trend in dust-storm frequency and duration sincethe 1960s was suggested for most places in northern Chinamainly due to the decreasing wind strength (Parungo andothers 1994 Shalamaiti 1996 Yang and others 1998) theincreasing trend of the Ca2+ and Mg2+ profile for recentdecades may reflect enhanced desertification and environ-mental deterioration in the Himalayan region

34 NH4+

The NH4+ profile is fairly flat until the 1940s then substan-

tially increases until the end of the 1980s with a slightdecrease during the 1990s (Fig 5)We compare our data withthe decadal-average NH4

+ concentration of an ice coredrilled on the glacier saddle Colle Gnifetti Monte Rosamassif (4450m asl) Switzerland whose NH4

+ level wasconstant until 1870 and increased afterwards by a factor ofthree (Dolaquo scher and others 1996) Dolaquo scher and others (1996)have suggested that the NH4

+ concentrations from the begin-ning of the 20th century are due to NH3 emissions in EuropeThe dominant NH3 emission in Europe arises from agricul-tural sources mainly bacterial decomposition of livestockwastes (81) and fertilizer application (Buijsman andothers1987)Therefore the slightly decreasing NH4

+ concen-trations of the ER core during the first half of the 20th cen-tury may reflect reduced agricultural activity in East andSoutheast Asia due to social turbulence especially duringWorld War IIwhile the sharp increase in NH4

+ concentra-tions during the second half of the 20th century may corres-pond to population explosion resulting in increasedagricultural activity In addition fertilizer was not widelyused throughout East and Southeast Asia until recentdecades Ammonium data from the Greenland Summit icecores also showed a significant increase by more than a factorof 2 since 1950 mainly for snow deposited during the winterhalf-year suggesting its anthropogenic origin (Fuhrer andothers 1996) Asman and others (1988) estimated a doublingof European NH3 emissions since 1920 based on livestockstatistics and they considered contributions of natural emis-sions to be already negligible in Europe by 1900 Our results

Fig 5Three-year smoothing results of the annual NH4+averages of the ER cores Coarse line for the NH4

+profile shows thepolynomial regressions to indicate its long-term variationsThe decadal values of NH4

+for an ice core from the glacier saddleColle Gnifetti Monte Rosa massif (4450 m asl) Switzerland are from Dolaquo scher and others (1996)


282

suggest that NH4+ did not originate substantially from

anthropogenic sources in the central Himalaya before1950Despite the 1991 Kuwait oil fires and the 1997 fires in

Kalimantan and Sumatra Indonesia (the ` best-estimatersquorsquototal NH3 emission is 2585 MtN for the Indonesia fires only(Levine 1999)) NH4

+ concentrations in the 1990s are lessthan in the 1980s According to the calculations of Lee andAtkins (1994) emissions of NHx(NH3 + NH4

+) from strawburning were equivalent to approximately 20 kt Na^1 in1981 and declined to 33 kt Na^1 in 1991 as a result of newagricultural practices Moreover fresh-snow chemistry(wet deposition) explicitly reflects monsoon air mass withmore marine origin (Shrestha and others 1997) Monsoonair masses travel over low-lying valleys and mountain slopesdominated by cultivated land forests and vegetation beforereaching our drilling site There are also many villageswhere animal husbandry and fertilization of fields withmanure is practised and burning of firewood is the mainsource of domestic energy Therefore the decline of NH4

+

concentrations in the 1990s may be attributed to either agri-cultural practices (eg ploughing the straw and stubble intothe soil instead of burning it) or changing sources of domes-

tic energy (eg hydropower oil or solar energy instead offirewood burning)

35 SO42^ and NO3

^

Significant variability is evident for the SO42^ and NO3

^

profiles (Fig 6) for example the maximum and minimumSO4

2^ and NO3^ concentrations are 53357 305 63107 and

048 ppb respectively However both the SO42^ and NO3

^

profiles show an apparent increasing trend especiallyduring the period 1940s^80s Data from the Dasuopu icecore also indicate double SO4

2^ and NO3^ concentrations

since 1860 (Thompson and others 2000) SO42^ and NO3

^

concentrations are highest in the 1990s for the Dasuopucore but there is a decline during this period for the ERrecordThis difference may be largely due to the lower-reso-lution sampling and averaging effect for the Dasuopu data

Previous studies have suggested that SO42^ and NO3

^ inthe Himalayan snow originate from several sources includ-ing crustal species (Mayewski and others 1983 Wake andothers 1993) biomass burning (Davidson and others 1986)and local acidic gases (Shrestha and others 1997) We note

Fig 6Three-year smoothing results of the annual SO42 and NO3

âverages of the ER cores Coarse lines for the SO42 and NO3

^

profiles show the polynomial regressions to indicate their respective long-term variationsThe decadal values of SO42 and NO3

^

for the Dasuopu core are adapted fromThompson and others (2000)

283


that the NO3^ concentration levels are similar for both the

Dasuopu and ER cores but SO42^ concentrations in the ER

core are roughly double those in the Dasuopu core whichmay be due to local human activity including that of climb-ing teams who visit the Everest region However the similartemporal variations for SO4

2^ NO3^ Ca2+ and Mg2+

records of the ER core still reflect the dominance of naturalforces in the Qomolangma (Mount Everest) region

Fifteen years (1980^95) of observations of weekly meanconcentrations of 18 constituents in the aerosol of the lowerArctic troposphere at Alert Canada indicated a markeddecrease of SO4

2^ and NO3^ since 1991 likely linked to the

collapse of industry in the early years of the new Eurasianrepublics (Sirois and Barrie 1999) The substantiallydecreased SO4

2^ and NO3^ concentrations of the ER core

in the1990s are consistent with the Arctic observationHow-ever the Dasuopo core does not reveal this decrease possi-bly because of the lower sample resolution at this site

4 CONCLUSIONS

Our results indicate that ice cores from high-elevation sitesin the Himalaya preserve information on the change ofmonsoon intensity anthropogenic activities and dust-stormhistory Such kinds of information are not only critical forunderstanding the mechanism of the South Asian monsoonsystem but also provide boundary conditions for bettermodeling and forecasting

The apparent spatial discrepancy for some ice-coreparameters shows the need for more cores from the Himalayain order to deduce the real signals and the regional chemicalcharacteristics For this purpose we have recovered a 1167 mbottom core at the col of ERGlacier (6550 m asl) in summer2001 and hope to recover more bottom cores in the Himalayanext year

ACKNOWLEDGEMENTS

We thank S Whitlow for chemical measurements of thesamples This research was supported by the Chinese Acad-emy of Sciences (KZCX1-10-02 KZCX2-108 KZCX2-301)Cold and Arid Regions Environmental and EngineeringResearch Institute (CACX210506 CACX210046) and theNational Natural Science Foundation of China (4987102249901004) Comments from anonymous reviewers improvedthe manuscript

REFERENCES

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Buck C F P A Mayewski M J Spencer S Whitlow M S Twickler andD Barrett 1992 Determination of major ions in snow and ice cores byion chromatography J Chromatogr Ser A 594(1^2) 225^228

Buijsman E H F M Maas and W A H Asman 1987 AnthropogenicNH3 emissions in Europe Atmos Environ 21(5)1009^1022

DansgaardW1964 Stable isotopes in precipitationTellus 16(4) 436^468

Davidson C I S Lin J F Osborn M R Pandey R A Rasmussen andM A K Khalil 1986 Indoor and outdoor air pollution in theHimalayas Environ SciTechnol 20(6) 561^567

Dolaquo scher A HW Galaquo ggeler U Schotterer and M Schwikowski 1996 Ahistorical record of ammonium concentrations from a glacier in theAlps Geophys Res Lett 23(20) 2741^2744

Fuhrer K A Neftel M Anklin T Staffelbach and M Legrand 1996High-resolution ammonium ice core record covering a completeglacialînterglacialcycle J Geophys Res 101(D2) 4147^4164

Hou Shugui Qin Dahe C P Wake and P A Mayewski 1999 Correspon-dence Abrupt decrease in recent snow accumulation at MountQomolangma (Everest) Himalaya J Glaciol 45(151) 585^586

Hou Shugui and 6 others Ren Jiawen 2002 Comparison of two ice-corechemical records recovered from the Qomolangma (Mount Everest)region Nepal Ann Glaciol 35 (see paper in this volume)

Kang Shichang C P Wake Qin Dahe P A Mayewski and Yao Tandong2000 Monsoon and dust signals recorded in Dasuopu glacier TibetanPlateau J Glaciol 46(153) 222^226

Lal M U Cubasch R Voss and J Waszkewitz 1995 Effect of transientincrease in greenhouse gases and sulphate aerosol on monsoon climateCurrent Sci 66 752^763

Lee D S and D H F Atkins 1994 Atmospheric ammonia emissions fromagricultural waste combustion Geophys Res Lett 21(4) 281^284

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Mayewski P A W B Lyons and N Ahmad 1983 Chemical compositionof a high altitude fresh snowfall in the Ladakh Himalayas Geophys ResLett 10(1)105^108

Mayewski P A W B Lyons N Ahmad G Smith and M Pourchet 1984Interpretation of the chemical and physical time-series retrieved fromSentik Glacier Ladakh Himalaya India J Glaciol 30(104) 66^76

Mudur G1995 Monsoon shrinks with aerosolmodels Science 270(5244)1922Parungo F Z Li X Li DYang andJ Harris 1994 Gobi dust storms and

the Great GreenWall Geophys Res Lett 21(11) 999^1002Qin Dahe and 9 others 2000 Evidence for recent climate change from ice

cores in the central Himalaya Ann Glaciol 31153^158Rozanski K L Araguas-Araguas and R Gonfiantini 1992 Relation

between long-term trends of oxygen-18 isotope composition of precipi-tation and climate Science 258(5084) 981^985

Shalamaiti 1996 [The characteristics of distribution of sandstorm in aperiod of time in the Tarim basin] [Arid Zone Research] 13(3) 21^27 [InChinese with English summary]

Shrestha A B CWake andJ Dibb1997 Chemical compositionof aerosoland snow in the high Himalaya during the summer monsoon seasonAtmos Environ 31(17) 2815^2826

Sirois A and L A Barrie1999 Arctic low tropospheric aerosol trends andcomposition at Alert Canada 1980^1995 J Geophys Res 104(D9)11599^11618

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Thompson L GTYao and E Mosley-Thompson2000 A high-resolutionmillennial record of the south Asian monsoon from Himalayan icecores Science 289(5486)1916^1919

Wake C P and M Stievenard1995The amount effect and oxygen isotoperatios recorded in Himalayan snow In Paleoclimate and environmentalvariability in Austral-Asian transect during the past 2000 years NagoyaNagoya University 236^241

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Whitlow S P A Mayewski and J E Dibb 1992 A comparison of majorchemical species seasonal concentration and accumulationat the SouthPole and Summit Greenland Atmos Environ 26A(11) 2045^2054

Wushiki H 1977 Deuterium content in the Himalayan precipitation atKhumbu District observed in 19741975 Seppyo Special Issue 39 Part II50^56

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284

AuthorsQin Dahe Hou Shugui Zhang Dongqi Ren Jiawen Shichang Kang Paul Andrew Mayewski and Cameron PWake

This conference proceeding is available at DigitalCommonsUMaine httpdigitalcommonslibraryumaineeduers_facpub138













1 INTRODUCTION



2 METHODOLOGY





278



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32 d18O





280



281



33 Ca2+ and Mg2+




34 NH4+












282






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35 SO42^ and NO3

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4 CONCLUSIONS



ACKNOWLEDGEMENTS


REFERENCES































284













1 INTRODUCTION



2 METHODOLOGY





278



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32 d18O





280



281



33 Ca2+ and Mg2+




34 NH4+












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35 SO42^ and NO3

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4 CONCLUSIONS



ACKNOWLEDGEMENTS


REFERENCES































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34 NH4+












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4 CONCLUSIONS



ACKNOWLEDGEMENTS


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35 SO42^ and NO3

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4 CONCLUSIONS



ACKNOWLEDGEMENTS


REFERENCES































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281



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34 NH4+












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35 SO42^ and NO3

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4 CONCLUSIONS



ACKNOWLEDGEMENTS


REFERENCES































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4 CONCLUSIONS



ACKNOWLEDGEMENTS


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4 CONCLUSIONS



ACKNOWLEDGEMENTS


REFERENCES































284

Preliminary results from the chemical records of an 80.4 m ice core recovered from East Rongbuk...

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