Detecting the Signature of Permafrost Thaw in Arctic Rivers

检测北极河流永久冻土融化的特征

• 批准号: 1500169
• 负责人: Robert Spencer
• 金额: $ 43.51万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-04 至 2017-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1500169&HistoricalAwards=false
• 关键词: Detecting; Signature; Permafrost; Thaw; Arctic

AbstractGlobal warming mobilization of the large (up to 50% of global) reservoirs of reduced organic carbon associated with northern permafrost regions of the Arctic, and conversion to radiatively important atmospheric (greenhouse) gases such as CO2 and CH4 presents a positive warming feed back of potentially considerable strength. Currently there is a lack of understanding of how fast and to what extent this stored organic matter is microbially transformed within Arctic watersheds and Arctic coastal systems. Despite the marked ?old? (14C depleted) label of permafrost carbon compared to contemporary organic matter, the comparitive lack of an ?aged? C signature in the downstream Arctic river systems presents something of a conundrum. Further, the rapid remineralization of permafrost reduced carbon is not consistent with the notion that reduced (permafrost) carbon is recalcitrant.This research aims to examine the partition, chemical and isotopic compositions, and ages of carbon species, including organic and inorganic/dissolved and particulate carbon, as well as lignin/lipid biomarkers in three subarctic/arctic rivers (Chena, Porcupine, and Sagavanirktok) and their basins. This will enable a comparison along a latitudinal gradient covering sporadic, discontinuous and continuous permafrost exposures, as well as along temporal scales from initial spring freshet to full summer and fall season and freeze-up.

与北极北部冻土区域相关的大量有机碳的大型（全球全球50％）储层的摘要global变暖动员，以及转换为辐射重要的大气（温室）气体，例如二氧化碳和CH4，呈现出阳性的阳性热量。潜在的强度。当前，缺乏了解这种存储的有机物在北极流域和北极沿海系统中微生物转化的速度和程度。尽管有标记吗？ （14C耗尽）与当代有机物相比，多年冻土碳的标签，相比缺乏？下游北极河系统中的c签名提出了一个难题。此外，多年冻土降低碳的快速再矿化与碳（多年冻土）碳是顽固的观念不一致。这项研究旨在检查分配，化学和同位素组成以及包括有机和无机/溶解和溶解和溶解和溶解和溶解的碳种类的分区，化学和同位素组成三个亚北极/北极河（Chena，Porcupine和Sagavanirktok）及其盆地中的颗粒碳以及木质素/脂质生物标志物及其盆地。这将使沿纬度梯度进行比较，该梯度涵盖了零星，不连续且连续的多年冻土暴露，以及从最初的Spring Freshet到完整的夏季和秋季季节和冻结的时间尺度。