Geochemistry of Trapped Gases in the GISP II Ice Core

9321623 Sowers该奖项旨在支持继续研究格陵兰冰盖项目二（GISP2）冰芯样品的甲烷浓度、氧、氮、氩的同位素组成和浓度以及总气体含量。 空气中的甲烷浓度代表着湿地的范围和它们所代表的温暖潮湿的气候。 甲烷也是一种影响气候的辐射活性气体。 空气中氧的同位素组成反映了陆地和海洋环境中初级生产的相对速率，以及生产性大陆地区的湿度。 甲烷和氧的同位素组成在整个大气中也是恒定的（或几乎恒定的）。 因此，它们可以作为格陵兰和南极冰芯相关的时间地层标志。 氮和氩的同位素指示了捕获过程中重力分馏的程度，并允许对这些气体的测量浓度和同位素组成进行校正。 总气体含量反映了冰盖的古海拔以及其他知之甚少的影响。 这项工作将提供关于地球历史上最后约25万年的气候和地球化学的信息。 ***

9321623 Sowers This award is for support to continue research on the concentration of methane, the isotopic composition and concentration of oxygen, nitrogen, argon, and total gas content of samples from the Greenland Ice Sheet Project Two (GISP2) ice core. The methane concentration of air is a proxy for the extent of wetlands and the warm, wet climates they signify. Methane is also a radiatively active gas which affects climate. The isotopic composition of oxygen in air reflects relative rates of primary production in the terrestrial and marine environments, and humidity in productive continental areas. Methane and the isotopic composition of oxygen are also constant (or nearly so) throughout the atmosphere at any one time. They therefore serve as time stratigraphic markers for correlating Greenland and Antarctic ice cores. Nitrogen and Argon isotopes indicate the extent of gravitational fractionation during the trapping process and allow for correction of the measured concentrations and isotopic compositions of these gases. Total gas content reflects paleoelevation of ice sheets among other poorly understood influences. This work will provide information on climate and biogeochemistry during the last approximately 250,000 years of Earth history. ***