摘要
本研究对钻取自青藏高原中部唐古拉冰川190m冰芯上部的99.5m序列进行了多参数指标的分析测试.以常规阴、阳离子的季节性变化、结合冰芯记录的1963年β活化度峰值和中低纬度山地冰川深部冰体定年模型,建立了99.5m冰芯的年代学序列.结合冰芯钻取点的成冰作用过程分析,明确了冰芯包裹气体与同层位冰体间不存在年龄差异,冰体年龄即为冰芯包裹气体年龄.基于此年代学结论和冰芯年代学结果,将冰芯包裹气体氧稳定同位素值(δ~(18 )O_(atm))与大气中δ~(18 )O_(atm)本底值、冰体气泡含量、冰芯氧同位素和全球太阳辐射量进行对比分析,分析揭示了唐古拉冰芯包裹气体δ~(18 )O_(atm)值变化对区域气候环境影响下冰川表面融化强度变化的指示意义,冰川表面融化强度越强,冰芯包裹气体δ~(18 )O_(atm)值越低.
Multiple parameter measurements were carried out on the top 99.5-meter sequence of a 190-meter ice core drilled from Tanggula glacier in Central Tibetan Plateau.Seasonal variations in conventional negative and cationic ions,1963peak of Beta activation,dating model of deep ice for mountain glacier were used to reconstruct the chronological sequence in the 99.5-meter ice core.Analysis of ice formation at the drilling site revealed no age difference between enclosed air bubbles and ice of the same layer.The age of ice was the age of enclosed air bubbles.Chronological results of the ice core were used to compare variations in stable oxygen isotope(δ~(18 )O_(atm)ratio)in enclosed air bubbles in ice core to background value ofδ~(18 )O_(atm)ratio in the atmosphere,air content in ice and global solar radiation.It was found that variation inδ~(18 )O_(atm)ratio in enclosed air bubbles in Tanggula ice core was closely related to changes in melting intensity of glacier surface.The stronger the melting intensity of the glacier surface,the lower the value ofδ~(18 )O_(atm)ratio in air bubbles of the ice core.
引文
[1]DOIE M.The relative atomic weight of oxygen in water and in air[J].Journal of the American Chemical Society,1935,57(12):2731
[2]LANE G A,DOLE M.Fractionation of Oxygen Isotopes during Respiration[J].Science,1956,123(3197):574
[3]BENDER M,SOWERS T,LABEYRIE T.The Dole effect and its variations during the last 130,000years as measured in the Vostok ice core[J].Global Biogeochemical Cycles,Global Biogeochernical Cycles,1994,8(3):363
[4]BENDER M L.Orbital tuning chronology for the Vostok climate record supported by trapped gas composition[J].Earth and Planetary Science Letters,2002,204:275
[5]SOWERS T,BENDER M,LABEYRIE L,et al.A135 000-year Vostok-Specmap common temporal framework[J].Paleoceanography,1993,8(6):737
[6]LEUENBERGER M C.Modeling the signal transfer of sea waterδ18 O to theδ18 O of atmospheric oxygen using a diagnostic box model for the terrestrial and marine biosphere[J].Journal of Geophysical Research-Oceans,1997,102(C12):26841
[7]SEVERINGHAUS J P,BEAUDETTE R,HEADIY MA,et al.Oxygen-18of O2records the impact of abrupt climate change on the terrestrial biosphere[J].Science,2009,324(5933):1431
[8]SHACKIETON N J.The 100 000-year ice-age cycle identified and found to lag temperature,carbon dioxide,and orbital eccentricity[J].Science,2000,289(5486):1897
[9]DREYFUS G B,PARRENIN F,LEMIEUX-DUDON B,et al.Anomalous flow below 2700min the EPICA Dome C ice core detected usingδ18 O of atmospheric oxygen measurements[J].Climate of the Past,2007,3(2):341
[10]CAPRON E,LANDAIS A,CHAPPELLAZ J,et al.Millennial and sub-millennial scale climatic variations recorded in polar ice cores over the last glacial period[J].Climate of the Past Discussions,2010,6:135
[11]HOU S,QIN D,ZHANG D,et al.A 154ahighresolution ammonium record from the Rongbuk Glacier,north slope of Mt.Qomolangma(Everest),TibetHimal region[J].Atmospheric Environment,2003,37(5):721
[12]张寅生,蒲健辰.青藏高原中部唐古拉山口邻近地区气候特征[J].冰川冻土,1994,16:41
[13]徐柏青.青藏高原达索普冰芯甲烷记录及其与气候变化的关系[D].兰州:中国科学院寒区旱区环境与工程研究所.2003
[14]PETRENKO V V,SEVERINGHAUS J P,BROOK EJ,et al.Gas records from the West Greenland ice margin covering the Last Glacial Termination:a horizontal ice core[J].Quaternary Science Reviews,2006,25:865
[15]CHAPPELLAZ J,BLUNIER T,RAYNAUD D,et al.Synchronous changes in atmospheric CH4and Greenland climate between 40and 8kyr BP[J].Nature,1993,366:443
[16]BARNOLA J M,ANKLIN M,PORCHERON J,et al.CO2evolution during the last millennium as recorded by Antarctic and Greenland ice[J].Tellus,1995,B47:264
[17]XU B,YAO T.Dasuopu ice core record of atmospheric methane over the past 2000years[J].Science in China Series D:Earth Sciences,2001,44:689
[18]侯书贵,秦大河,皇翠兰.唐古拉山冬克玛底冰川雪冰层中淋溶作用的初步研究[J].冰川冻土,1996,18(3):53
[19]LI J,XU B Q,CHAPPELLAZ J.Variations of air content in Dasuopu ice core from AD 1570~1927and implications fore climate change[J].Quaternary International,2011,236:91
[20]郑伟.青藏高原中部唐古拉冰芯气候环境记录研究[D].北京:中国科学院青藏高原研究所,2008
[21]JOSWIAK D R,YAO T,WU G,et al.A 70-yr record of oxygen-18variability in an ice core from the Tanggula Mountains,central Tibetan Plateau[J].Climate of the Past,2010,6:219
[22]BOLZAN J F.Ice flow at the Dome C ice divide based on a deep temperature profile[J].Journal of Geophysical Research,1985,90:8111
[23]HUBER C,LEUENBERGER M,SPAHNI R,et al.Isotope calibrated Greenland temperature record over Marine Isotope Stage 3and its relation to CH4[J].Earth and Planetary Science Letters,2006,243(3/4):504
[24]STEINHILBER F,BEER J,FRHLICH C.Total solar irradiance during the Holocene[J].Geophysical Research Letters,2009,36,L19704.DOI:10.1029/2009GL040142