Sources and oceanic paths of large meltwater discharge events and their roles in abrupt holocene climatic events

大规模融水排放事件的来源和海洋路径及其在全新世突发气候事件中的作用

• 批准号: 341997-2007
• 负责人: Levac, Elisabeth
• 金额: $ 1.59万
• 依托单位: Bishop's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=458694
• 关键词: Sources; oceanic; paths; large; meltwater

My research program will provide a better understanding of abrupt climatic changes that occurred during the last 11,000 years, a topic currently of interest to the United Nations Intergovernmental Panel on Climate Change (IPCC), in view of the potentially serious implications such abrupt changes have on human societies. These events are difficult to replicate using numerical climate models, so paleoclimatic proxy data is indispensable to their study. It is not possible now to identify the primary cause of abrupt climatic events among meltwater discharges, natural climatic variability, shifts in oceanic currents, and solar influence. Since there is not even consensus about the source and routing (path) of some large meltwater releases that occurred during the last deglaciation, it is not possible to confirm or rule out their role in abrupt climate cooling events. This project will focus on meltwater source and paths believed to have caused such severe cooling events as the Younger Dryas and the Preboreal oscillation. I will verify if large amounts of meltwater from glacial Lake Agassiz (and/or other glacial lakes) were discharged through the St. Lawrence River between 11,000 and 7000 years ago. In order to do so, I will study high resolution marine sediment cores from strategic locations to detect any meltwater releases through that route. Sea surface temperature and salinity will be reconstructed using dinoflagellate cysts data and transfer functions. These paleoceanographic records will also be used to document the frequency and amplitude of natural climatic variability in that region. Knowing the frequency of these oscillations might help to identify their causes and will contribute to the better knowledge of our climate system.

我的研究计划将更好地理解过去11，000年来发生的突然气候变化，这是联合国当前对气候变化的政府间小组（IPCC）感兴趣的话题，鉴于潜在的严重影响，这种突破的变化在人类社会。这些事件很难使用数值气候模型复制，因此古气候代理数据对于他们的研究是必不可少的。现在，无法确定融化出排放，自然气候变异性，海洋电流变化和太阳影响的主要原因的主要原因。由于关于上次脱气过程中某些大型熔融释放的源和路由（路径）甚至没有共识，因此无法确认或排除其在突然的气候冷却事件中的作用。该项目将集中于融水源和据信导致诸如年轻的Dryas和孔波前振荡等剧烈冷却事件的路径。我将验证是否在11,000至7000年前从圣劳伦斯河（St. Lawrence River）出院，是否从冰川湖Agassiz（和/或其他冰川湖）出发了大量的融水。为了做到这一点，我将研究从战略位置的高分辨率海洋沉积物核心，以检测通过该路线的任何融水释放。海面温度和盐度将使用鞭毛藻囊肿数据和转移功能重建。这些古环记录还将用于记录该地区自然气候变化的频率和幅度。了解这些振荡的频率可能有助于确定其原因，并有助于对我们的气候系统的更好了解。