Collaborative Research: Arctic to the Amazon: Physical Processes Controlling Gas Exchange from Freshwater Ecosystems.

对二氧化碳和甲烷排放量的估计表明，内陆水生生态系统在从地方生态系统尺度到区域和全球尺度的多个尺度上的碳平衡中发挥着重要作用。鉴于全球变暖和人类活动导致的地球化学循环的持续变化，世界各地正在进行研究，以更准确地评估湖泊和水库在区域和全球碳循环中的作用，并估计湖泊中的代谢活动。这些努力的关键是准确估计空气和水界面的气体通量，但当前的模型并不包括介导气体交换的所有物理过程。这种多尺度的建模研究包括现场测量的气体交换和过程控制气体交换的范围内的淡水水体从小型北极湖泊的亚马逊河流域的大型洪泛平原湖泊。这些数据将用于开发淡水生态系统的气体交换模型，其中不仅包括风速，还包括使空气和水之间的界面通量的所有物理过程。它们还将考虑到暖水湖和冷水湖的主要过程的差异。新的模型，加上对促进气体交换的基本动力学的更好理解，将有助于改进对全球各个淡水水体温室气体通量的估计，并在广泛区域内准确扩大估计，其结果将为全球湖泊生态观测站网络世界各地的站点和国家生态观测站网络内拟议的湖泊站点的程序提供信息。 美国和国外的博士后研究员和研究生将接受微气象学、湖沼学和地球化学方面的培训。 主要调查员将为实地课程和在美国、瑞典和巴西举行的国家会议上举办技术讲习班作出贡献或举办讲习班。

Estimates of carbon dioxide and methane emissions indicate inland aquatic ecosystems play an important role in carbon balances across multiple scales ranging from the local ecosystem scale to regional and global scales. Given ongoing changes in biogeochemical cycles due to global warming and human activities, studies are being conducted worldwide to more accurately assess the role of lakes and reservoirs in regional and global carbon cycles and to estimate metabolic activity in lakes. Essential to these efforts are accurate estimates of gas fluxes at the air and water interface, yet current models do not include all the physical processes which mediate gas exchange. This multiscale modeling research includes field measurements of gas exchange and of processes controlling gas exchange across a range of freshwater bodies from small arctic lakes to the large floodplain lakes of the Amazon. These data will be used to develop gas exchange models for freshwater ecosystems that include not just wind speed but the full range of physical processes that enable fluxes across the interface between air and water. They will also take into account the differences in dominant processes in warm versus cold water lakes. The new models, combined with improved understanding of the underlying dynamics enabling gas exchange, will enable improved estimates of greenhouse gases fluxes from individual freshwater bodies worldwide and accurate scaling up of estimated over broad regions.Results will inform procedures at Global Lake Ecological Observatory Network sites worldwide and proposed lake sites within the National Ecological Observatory Network. Postdoctoral fellows and graduate students in the United States and abroad will receive training in micrometeorology, limnology and biogeochemistry. The principle investigators will contribute to or conduct workshops on techniques for field courses and at national meetings in the United States, Sweden and Brazil.