Circulation, Metabolism, and Greenhouse Gas Emissions from Arctic Lakes and Ponds

这项拟议研究的目标是通过分析三年来从五个湖泊获得的数据，检查冰盖覆盖的北极湖泊的生物、化学和物理条件以及相关的溶解气体变化。这些数据将被用来1)确定冰下生物的循环和由此产生的栖息地，以及2)生物和物理过程如何相互作用，导致氧气损失和温室气体产生。尽管在湖泊中混合对于维持健康的栖息地很重要，但在美国，很少有科学家接受过湖泊物理方面的培训。该项目将为博士后学者提供这样的培训。北极湖泊一年中有九个月或更多月份被冰覆盖。在严酷的冬季条件下，极少有人对冰盖覆盖的北极湖泊进行湖沼学研究。这项拟议研究的目标是分析三年来从五个不同大小的湖泊获得的史无前例的数据集。这些数据将被用来描述和量化湖泊的物理湖沼学和冰新陈代谢下的湖水，并制定比例定律，以便可以进行区域概括。分析和模拟将侧重于以下问题：在冰温和环流下秋季降温减缓的程度；呼吸作用及相关溶质增加对环流模式和缺氧发展的贡献；对融雪时引入的溶质保留量的依赖于湖泊的控制；以及对混合动态的依赖于湖泊大小的控制，这些控制在冬季调节二氧化碳和CH4的产生，在冰盖关闭时调节排放。结果将为改进水动力学模型所需的环流和混合提供基本的理解，对于量化冰下生物的栖息地和准确地将北极湖泊纳入区域碳收支至关重要。

The goals of the proposed research are to examine biological, chemical, and physical conditions in ice-covered Arctic lakes and the associated changes in dissolved gases by analyzing data obtained from five lakes over three years. The data will be used to 1) determine circulation and the resulting habitat for organisms living under the ice, and 2) how biological and physical processes interact to cause a loss of oxygen and the production of greenhouse gases. Despite the importance of mixing within lakes for maintaining healthy habitats, few scientists are trained in lake physics in the United States. This project will provide such training for a postdoctoral scholar. Arctic lakes are ice-covered for nine or more months of the year. With harsh winter conditions, few limnological studies have been conducted on ice-covered arctic lakes. The goal of the proposed research is to analyze an unprecedented dataset obtained from five lakes of different sizes from fall to spring over three years. The data will be used to describe and quantify the lakes' physical limnology and under ice metabolism and to develop scaling laws such that regional generalizations can be made. Analyses and modeling will focus on questions related to the extent to which fall cooling moderates under ice temperatures and circulation; the contribution of respiration and related increases in solutes to circulation patterns and development of anoxia; lake-size dependent controls on the retention of solutes introduced at snowmelt; and lake-size dependent controls on mixing dynamics, which moderate production of CO2 and CH4 in winter and emissions at ice off. Results will provide a basic understanding of circulation and mixing as needed to improve hydrodynamic models and are critical for quantifying the habitat of organisms under the ice and for accurate inclusion of arctic lakes in regional carbon budgets.