Climatology, Meteorology, and Microbial Metabolism in Ice with Dust Loggers and Fluorimetry

PRICE 0738658该奖项支持一个项目，该项目使用两个新的扫描荧光仪来绘制WAIS Divide冰芯中微生物浓度与深度的关系图，因为NICL提供了部分WAIS Divide冰芯，而GISP2冰芯的选定部分用于半球间比较。用冰中微生物进行的地面校准表明，这些仪器对单个细胞很敏感，可以在两分钟内以300微米的间隔扫描1米长的岩芯。这些研究的目标将是利用这样一个发现：微生物每年成团地传输到冰上几次，而且很少有间隔(不是周期性的)大约104年的时间，更高的流量，有时持续10年，到达冰上。南极和北极冰层中光养生物、产甲烷菌和微生物总数的到达时间分布从季节性到千禧年再到冰川尺度的变化，研究人员将试图确定这些微生物的海洋和陆地来源，并寻找微生物爆发与粉尘浓度和温度指标的相关性。此外，该项目还将跟进这一发现，即非常高的微生物通量的罕见实例解释了冰芯中的一些“气体人工制品”--在以前的气候研究中，其他人已经丢弃了多余的CH4和N2O的孤立尖峰。这个项目的学术价值在于，它将利用微生物扫描荧光测定法作为一种强大的新工具，用于从气象学到气候学再到生物学的研究，特别是当与绘制尘埃、气体和冰芯中主要元素化学的地图相结合时。在2010-11年度，将使用最新版本的粉尘记录仪记录WAIS分隔孔。该测井将提供毫米尺度的粉尘浓度和整个钻孔深度下的火山灰层的深度分辨率。将确定冰层中火山灰的位置，并对火山灰进行化学分析，以确定来源。通过将WAIS Divide钻孔的数据与其他钻孔的数据以及火山层的化学数据(由他人获得)进行比较，研究人员将研究火山喷发的时间与气候突然变化之间的关系。该项目的扫描荧光仪和尘埃记录仪的结果可以应用于行星任务、钻孔海洋学、湖沼学、气象学、气候学、火山学和古代冰中生命。更深入地了解气候突然变化的原因，包括与火山爆炸性的因果关系，将有助于更好地了解对气候的不利影响。该项目更广泛的影响是，它将为来自美国和其他国家的学生和博士后提供培训。

Price 0738658This award supports a project to use two new scanning fluorimeters to map microbial concentrations vs depth in the WAIS Divide ice core as portions of it become available at NICL, and selected portions of the GISP2 ice core for inter-hemispheric comparison. Ground-truth calibrations with microbes in ice show that the instruments are sensitive to a single cell and can scan the full length of a 1-meter core at 300-micron intervals in two minutes. The goals of these studies will be to exploit the discovery that microbes are transported onto ice, in clumps, several times per year and that at rare intervals (not periodically) of ~104 years, a much higher flux, sometimes lasting 1 decade, reaches the ice. From variations ranging from seasonal to millennial to glacial scale in the arrival time distribution of phototrophs, methanogens, and total microbes in the Antarctic and Arctic ice, the investigators will attempt to determine oceanic and terrestrial sources of these microbes and will look for correlations of microbial bursts with dust concentration and temperature proxies. In addition the project will follow up on the discovery that the rare instances of very high microbial flux account for some of the"gas artifacts" in ice cores - isolated spikes of excess CH4 and N2O that have been discarded by others in previous climate studies. The intellectual merit of this project is that it will exploit scanning fluorimetry of microbes as a powerful new tool for studies ranging from meteorology to climatology to biology, especially when combined with mapping of dust, gases, and major element chemistry in ice cores. In 2010-11 the WAIS Divide borehole will be logged with the latest version of the dust logger. The log will provide mm-scale depth resolution of dust concentration and of volcanic ash layers down the entire depth of the borehole. The locations of ash layers in the ice will be determined and chemical analyses of the ash will be analyzed in order to determine provenance. By comparing data from the WAIS Divide borehole with data from other boreholes and with chemical data (obtained by others) on volcanic layers, the researchers will examine the relationship between the timing of volcanic eruptions and abrupt climate change. Results from this project with the scanning fluorimeters and the dust logger could have applications to planetary missions, borehole oceanography, limnology, meteorology, climate, volcanology, and ancient life in ice. A deeper understanding of the causes of abrupt climate change, including a causal relationship with volcanic explosivity, would enable a better understanding of the adverse effects on climate. The broader impact of the project is that it will provide training to students and post-docs from the U. S. and other countries.