Detecting hydrological and carbon-cycle change in high-latitude environments with compound-specific isotope analyses

通过化合物特异性同位素分析检测高纬度环境中的水文和碳循环变化

• 批准号: RGPIN-2017-03902
• 负责人: Douglas, Peter
• 金额: $ 1.97万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=649516
• 关键词: Detecting; hydrological; carbon; cycle; change

Arctic and Subarctic regions of the Earth are warming faster than the rest of the planet, and this climate change will probably strongly affect water resources in these regions, as well as the amount of natural carbon greenhouse gas emissions (e.g. carbon dioxide and methane) they produce. However, the effects of climate change on water and carbon cycling in Arctic regions are not well understood. The proposed research will seek to gain a better understanding of these aspects of Arctic environmental change, both by studying how Arctic environments changed during past periods with warm climates, and by gathering detailed information about how water and carbon move through Arctic environments today. This research is performed by analyzing the natural abundance of rare isotopes, or atoms with slightly heavier-than-normal masses, in individual organic molecules found in lake sediments. When water or carbon moves between different environments the abundance of their isotopes changes, and because of this, isotope measurements can provide a record of environmental change. This research will focus on analyzing isotope ratios in individual organic molecules produced by different organisms, a novel approach that will avoid uncertainties associated with other isotope analyses. Specific questions this research will help address include: 1) How did rainfall and lake levels change in Northeastern Canada when temperatures became warmer or cooler; 2) What happens to carbon when it moves from soils to lakes, and can it be stored in lake sediments for long periods of time; 3) What controls how much methane is produced in lakes, and how much of that methane escapes to the atmosphere.******This research is important because it will provide new data on how Arctic ecosystems responded to climate change in the past, and will help to predict how these ecosystems could change in the future. This is necessary for climate scientists and policymakers who need to understand how different parts of the world will respond to global warming. This research is also important to Canadians who live in northern regions, since it can help to explain the dramatic changes that are occurring in their home. This research will benefit Canadians by giving a clearer picture of both the future of water resources in northern regions and the risk that northern environments will begin to emit more greenhouse gases as the climate warms.*****

北极和亚北极地区的变暖速度比地球上其他地区更快，这种气候变化可能会严重影响这些地区的水资源，以及它们产生的天然碳温室气体排放量(例如二氧化碳和甲烷)。然而，气候变化对北极地区水和碳循环的影响还不是很清楚。拟议的研究将寻求更好地了解北极环境变化的这些方面，既研究过去气候温暖时期北极环境是如何变化的，也通过收集关于水和碳如何在今天的北极环境中移动的详细信息来实现。这项研究是通过分析湖泊沉积物中发现的单个有机分子中稀有同位素的自然丰度进行的，稀有同位素是指质量略高于正常质量的原子。当水或碳在不同环境之间移动时，它们的同位素丰度会发生变化，因此，同位素测量可以提供环境变化的记录。这项研究将侧重于分析不同生物体产生的单个有机分子中的同位素比率，这是一种新的方法，将避免与其他同位素分析相关的不确定性。这项研究将帮助解决的具体问题包括：1)当气温变暖或变冷时，加拿大东北部的降雨量和湖泊水位是如何变化的；2)碳从土壤转移到湖泊时会发生什么，它能否长期储存在湖泊沉积物中；3)是什么控制着湖泊中产生多少甲烷，以及有多少甲烷逃逸到大气中。*这项研究之所以重要，是因为它将提供有关北极生态系统过去如何应对气候变化的新数据，并将有助于预测这些生态系统未来可能如何变化。这对于气候科学家和政策制定者来说是必要的，他们需要了解世界不同地区将如何应对全球变暖。这项研究对生活在北部地区的加拿大人也很重要，因为它可以帮助解释他们的家园正在发生的戏剧性变化。这项研究将使加拿大人更清楚地了解北部地区水资源的未来，以及随着气候变暖，北部环境将开始排放更多温室气体的风险。