Multivariate Paleoclimatic Analysis in Southern South America with Emphasis on Transitional Periods

Markgraf, Vera White, James W.C.科罗拉多大学标题：南美洲南部的多变量古气候分析，重点是过渡时期该奖项支持使用花粉和稳定同位素分析南美南部泥炭岩心的多变量古气候研究。这些岩心被认为包含了自末次冰期/间冰期转变以来的连续记录。迄今为止，在比格尔海峡纬度55°处对一个泥炭岩心进行了高分辨率的综合分析，结果表明，花粉地层学为更好地评估稳定同位素比率提供了视角，并且综合方法大大增加了古气候信息。目前的工作目标有三个方面：1)通过对苔藓的实验实验室研究和对现代沼泽的深入野外研究来完善稳定同位素数据的校准；2)采用相同的方法，通过分析同一一般气候区的其他记录来确认古气候变化的历史；3)通过分析南美南部不同地区和北半球的其他记录，证实了过去二氧化碳分压变化的记录。结合几个岩心的古气候和古二氧化碳浓度记录将有助于更好地理解气候突变事件的机制和动力学。

Abstract ATM-9321857 Markgraf, Vera White, James W.C. University of Colorado Title: Multivariate Paleoclimatic Analysis in Southern South America with Emphasis on Transitional Periods This award supports a multivariate paleoclimate study, using pollen and stable isotope analyses, of peat cores from southern South America. These cores are believed to contain a continuous record since the last glacial/interglacial transition. Results obtained to date from the combined high resolution analyses of one peat core, at latitude 55o in the Beagle Channel, indicate that the pollen stratigraphy provides the perspective against which stable isotope ratios can be better evaluated and that the combined approach greatly augments the paleoclimatic information. The goal of the present effort is threefold: 1) refine the calibration of the stable isotope data by both experimental laboratory studies with mosses and indepth field studies of modern bogs; 2) confirm the history of paleoclimatic change by analyzing other records from the same general climatic region using the same approach; and 3) confirm record of past changes in pCO2 by analyzing other records from different regions in southern South America and also from the northern hemisphere. The combination of records of paleoclimatic and paleo-carbon dioxide concentrations from several cores will lead to a better understanding of the mechanisms and dynamics of abrupt climate change events.