黔北洞穴石笋记录的末次冰消期至早全新世百年～十年际气候变化  

The Centennial to Decadal Scale Variation of Summer Monsoon Precipitation in Northern Guizhou Province During the Last Deglacial

作　　者：姜修洋[1,2] 杨邦[2] 王晓艳[2] 何尧启[3] 段福才[4] 李志忠[1] 沈川洲[5] 

机构地区：[1]福建师范大学地理研究所,福建福州350007 [2]福建师范大学地理科学学院湿润亚热带生态地理过程教育部重点实验室,福建福州350007 [3]贵州民族大学旅游与航空服务学院,贵州贵阳550025 [4]南京师范大学地理科学学院,江苏南京210046 [5]台湾大学地质科学系,台湾台北10617

出　　处：《地理科学》2015年第6期773-781,共9页Scientia Geographica Sinica

基　　金：国家自然科学基金(41372189);福建省公益类研究所基本科研项目(2014R1034-2)资助

摘　　要：通过黔北三星洞2支石笋(编号:SX3-a和SX14)的25个高精度230Th年龄(测年误差≤76 a)和740个氧同位素数据,重建了末次冰消期至早全新世(16.82±0.04~8.29±0.03 ka B.P.)平均分辨率达10 a的亚洲夏季风演变历史。无论在千年尺度还是百年尺度,甚至是十年际气候事件上,三星石笋δ18O记录的季风气候与北高纬气候都存在耦合关系。然而,在波令-阿勒罗德(B?lling-Aller?d)时期,与格陵兰冰芯所记录的温度逐渐回冷的趋势相反,亚洲夏季风表现出逐渐增强的过程。太阳辐射能量的增加和越赤道气流的增强有可能是引起此时期夏季风增强的主要原因。在前北方期(11.7~9 ka B.P.)时,南极温度、大气CO2浓度和CH4浓度等在新仙女木(Younger Dryas,YD)结束后均达到最大值,而石笋δ18O记录表明在YD冷事件结束后,直到9 ka B.P.左右亚洲夏季风才达到最盛期。冰消期结束后,虽然太阳辐射能量已经达到高值,但直到9 ka B.P.之前,北美大陆仍然残留较大的冰盖,有可能对夏季风的增强起到一定的限制作用。另外,早全新世南极变冷同样有可能通过加强越赤道气流来影响夏季风气候。The last deglaciation, transition from the last glacial maximum to the present interglacial(Holocene),has great importance in understanding how Earth's climate system can abruptly switch from one state to another. This transition was also characterized by several abrupt climatic oscillations, including Heinrich event 1,B?lling-Aller?d, and Younger Dryas. However, uncertainty remains regarding the similarities and differences in monsoon history in different region. Here, we present a high-resolution(10-year on average) monsoonal record covering the time range from 16.82±0.04 to 8.29±0.03 ka BP, Based on 25 high-precision230 Th dates and740 Oxygen isotopic data from stalagmite SX3-a and SX14 from Sanxing Cave, Northern Guizhou Province,China, an average 10 a resolution Asian Summer Monsoon(ASM) record during the last deglacial was produced. Millennial- to decadal- scale coupling between the ASM and northern high-latitude climate persisted through whole last deglacial period, suggesting that the Atlantic meridional circulation play a role in monsoon climate. Decoupled from decreasing temperatures in Greenland during the BA, the concurrent intensified AM is likely attributed to the increasing insolation and the strong cross-equatorial flow. During the'Preboreal episode', Antarctic temperature, atmospheric CO2 and CH4were reached to its maximum values after the abrupt transition of Younger Dryas. Howerver, ASM experienced a 2.7 ka-long gradual increase of the monsoon rainfall. The summer insolation in the North Hemisphere was maximal at around 11,000 a B.P., however, until about 9 000 a B.P. a large remnant ice sheet persisted in North America, which could be impede the rebound of ASM. In addition, the cooling of the Antarctic during the early Holocene maybe also influenced ASM through the strong cross-equatorial flow.

关 键 词：冰消期 前北方期 黔北 石笋 百年~十年际尺度 

分 类 号：P532[天文地球—古生物学与地层学]