Time series of water temperature, specific conductance and oxygen from Lake E1, North Slope, Alaska, 2012-2013

Lakes are abundant in the terrestrial arctic, extending over about one quarter of the territory. For approximately nine months of the year, the waters of arctic lakes are under ice. Despite the duration of the ice-covered period, few studies have addressed the limnology (biological, chemical, and physical features) of these lakes during winter and how conditions under ice affects the stratification of lakes during the summer. We aim to look at the full year cycle lake circulation in order to quantify the effects of hydrodynamics on nutrient and gas fluxes and place the results within the context of climate change in the Arctic. The goals of our study include: (1) quantifying physical and biogeochemical controls on under ice thermal structure and circulation, the flowpath of snow melt, and mixing during spring and fall (2) quantifying respiration rates in arctic lakes of differing morphology and on geological substrates (3) illustrating the linkages and feedbacks between these physical and biogeochemical processes. Our research is being conducted in lakes studied by the Arctic Long Term Ecological Research (ARC LTER). The selected lakes are: Toolik Lake, Lake E1, Lake E5, Lake E6 and Lake N2. The Lakes range in size from 1 to 1500 hectares. Time series of water temperatures, specific conductance and dissolved oxygen at several depths were obtained from a taut-line mooring in different seasons (summer and winter) across multiple years (between fall 2012 and fall 2016).

陆地北极地区湖泊分布广泛，其面积约占该区域总面积的四分之一。北极湖泊的水体全年有约九个月处于冰封状态。尽管冰封期持续时间漫长，但针对冬季北极湖泊的湖沼学（生物学、化学与物理特征），以及冰封下环境如何影响夏季湖泊分层的研究仍较为匮乏。本研究旨在探究湖泊全年环流周期，以量化水动力过程对营养盐与气体通量的影响，并将研究结果置于北极气候变化的背景之下。本研究的目标包括：（1）量化冰封期热结构与环流、融雪径流路径，以及春秋季节混合过程的物理与生物地球化学调控机制；（2）测定不同形态学特征且位于不同地质基底上的北极湖泊的呼吸速率；（3）阐明上述物理与生物地球化学过程之间的关联与反馈机制。本研究的观测湖区选自北极长期生态研究（ARC LTER）站点的已研究湖泊。入选的观测湖泊包括图利克湖（Toolik Lake）、E1湖、E5湖、E6湖与N2湖。这些湖泊的面积介于1至1500公顷之间。研究团队于2012年秋季至2016年秋季的多个年份，在夏季与冬季等不同季节，通过张紧式锚泊系统（taut-line mooring）获取了不同深度的水温、比电导率与溶解氧时间序列数据。