IRFP: GENIE Modeling of Paleogene Hyperthermals

国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。项目？S奖提供了联合研究的机会，并利用国外独特或互补的设施、专业知识和实验条件。该奖项将资助桑德拉·柯特兰·特纳博士与英国布里斯托尔大学的安迪·里奇韦尔博士合作的为期24个月的研究奖学金。到21世纪末，大气中温室气体的持续积累意味着地球气候的辐射强迫将超过地球上数千万年来看到的任何东西。在约40 Ma以前，在温暖的温室气候中发生的大量突然变暖事件(高温)为我们提供了对未来气候变化的最佳类比。在这些事件期间，有证据表明，大量碳迅速注入海洋和大气，同时伴随着剧烈的变暖和海洋酸化。这些事件的特点，包括它们的规律性发生和快速恢复，表明在温暖气候下对碳循环不稳定性和反馈的理解存在差距。为了充分利用这些事件的潜力，为地球对化石燃料排放的预测长期反应提供信息，至关重要的是将重建这些事件的数据集与测试关于控制其发生的假设的模型结合起来。这项研究使用了一个中等复杂性的地球系统模型，称为GENIE(网格使能的集成地球系统模型)，以测试有关温室地球上引发和终止高温事件的机制的关键问题。第一个目标是使用GENIE模型来评估单个古气候记录在记录气候突变时的保真度。这项工作涉及制定一种方法，通过纳入和系统地评估影响保存地质记录中事件大小和形状的偏差，改进对这些事件规模的估计。第二个目标是为GENIE增加关键的模型能力，这将1)能够研究地球轨道的变化如何影响高温事件的时间和大小，2)测试尚未明确包括在现有碳循环-气候模型中的碳源的作用。除了她的研究，柯特兰·特纳博士还对古气候学和碳循环气候模型的更广泛的社会和政治影响感兴趣。她希望利用她对高温事件的重建和建模的结果来教育公众和政策制定者，了解化石燃料二氧化碳排放的真实寿命以及气候变暖的特征。最后，这项研究将有助于在加州拉霍亚的斯克里普斯海洋研究所(理查德·诺里斯博士？研究小组)和英国布里斯托尔大学的Ridgwell？S博士研究小组。

The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program?s awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise, and experimental conditions abroad. This award will support a twenty-four month research fellowship by Dr. Sandra Kirtland Turner to work with Dr. Andy Ridgwell at the University of Bristol in Bristol, United Kingdom.By the end of the 21st century, the continued build-up of greenhouse gases in the atmosphere means that radiative forcing of Earth's climate will surpass anything seen on Earth for tens of millions of years. Numerous abrupt warming events (hyperthermals) that occurred in the warm, 'greenhouse' climate before ~40 Ma provide our best analogs for future climate change. During these events, there is evidence for rapid injections of massive amounts of carbon into the oceans and atmosphere, accompanied by intense warming and ocean acidification. Characteristics of these events, including their regular occurrence and fast rate of recovery, suggest gaps in understanding of carbon cycle instabilities and feedbacks in a warm climate. To fully exploit the potential of these events to inform Earth's predicted long-term response to fossil fuel emissions, it is critical to combine datasets that reconstruct these events with models that test hypotheses regarding the controls on their occurrence. This research uses an Earth system model of intermediate complexity called GENIE (Grid-Enabled Integrated Earth system model) to test key questions regarding the mechanisms responsible for initiating and terminating hyperthermal events on a greenhouse Earth. The first objective is to use the GENIE model to assess the fidelity of individual paleoclimatic records in recording abrupt climate transitions. This exercise involves the development of a methodology to improve estimates of the size of these events by incorporating and systematically assessing the biases that influence preservation of event size and shape in the geologic record. The second objective is to add key model capabilities to GENIE that will 1) enable study of how variations in Earth's orbit impact the timing and size of hyperthermal events and 2) test the role of carbon sources that are not yet explicitly included in existing carbon cycle-climate models. In addition to her research, Dr. Kirtland Turner is interested in the broader social and political implications of paleoclimatology and carbon cycle-climate modeling. She hopes to use results from her reconstruction and modeling of hyperthermal events to educate the public and policymakers about the true lifetime of fossil fuel CO2 emissions and characteristics of a warm world. Finally, this research will help develop new international collaborations between the PI, collaborators at Scripps Institution of Oceanography in La Jolla, CA (Dr. Richard Norris? research group), and Dr. Ridgwell?s research group at the University of Bristol, U.K.