PostDoctoral Research Fellowship

申请人将利用该极地博士后奖学金研究北极生态系统如何对先前的变暖事件作出反应，以限制目前对生态系统对全球变化的反应的预测。申请人先前的研究表明，上新世（距今500万年至200万年）北极的表面温度可能比以前认为的要高得多。他将通过一种多代理方法来发展这一想法，通过分析一系列保存下来的哺乳动物化石骨骼胶原蛋白中的碳和氮的稳定同位素来重建上新世的北极温度和降水，并将确定生态系统结构的定量指标。然后将这些指标与现代北方森林的值进行比较，以确定两个生物群落之间的显著差异。对温度和相对湿度的经验估计将与上新世北极气候的模式模拟进行比较，以确定可能放大高纬度地区气候敏感性的气候反馈。

The applicant will use this Polar Postdoctoral Fellowship to investigate how arctic ecosystems have responded to prior occurrences of warming in order to constrain current forecasts of ecosystem response to global change. The applicant's prior research indicates that Pliocene (app. 5 to 2 million years before present) surface temperatures in the Arctic may have been considerably warmer than previously thought. He will develop this idea through a multi-proxy approach to reconstructing arctic temperature and precipitation in the Pliocene by analyzing stable isotopes of carbon and nitrogen in the collagen of fossil bones from an array of preserved mammals, and will determine quantitative metrics of ecosystem structure. These metrics will then be compared with values from the modern boreal forest to identify the significant characteristics that differ between the two biomes. Empirical estimates of temperature and relative humidity will be compared with model simulations of Pliocene Arctic climates to identify climate feedbacks that may amplify climate sensitivity at high latitudes.