AGS-PRF: Soil Exchange of Carbonyl Sulfide (COS): Towards an Independent Proxy for Terrestrial Gross Primary Production (GPP)

该博士后研究奖学金支持一系列实地和实验室实验，以证明使用大气羰基硫化物（COS）作为陆地初级生产总量的独立代理。总初级生产量是指陆地植物在单位时间内通过光合作用将二氧化碳还原成有机化合物而“固定”的二氧化碳总量。它是描述碳-气候反馈、评估基于生态系统的二氧化碳捕集与封存项目的重要参数，也是生态系统碳交换模型的重要输入参数。这位研究者积极参与教育和推广活动，以提高科学素养。为了在生态系统尺度上使用COS交换作为碳吸收的近似值，需要表征COS的土壤交换速率，以区分COS植物消耗和土壤中COS的吸收。研究人员正在开发一种新的应用同位素池稀释技术（使用13COS），以测量土壤COS的消耗和产生，从而解开控制净COS交换的因素。她将进行受控的实验室实验，以评估环境变量（如温度、紫外线和土壤中的酶活性）对COS交换变化的作用。现场测量将在不同的地点进行，包括南加州的一个高山梯度，这是一个指定的FLUXNET地点，以及一个灌木林和一个沙漠地点，该地点已经安装了涡流通量塔，并持续监测环境变量。FLUXNET是一个区域网络，每个参与站点使用涡动相关方法来测量陆地生态系统与大气之间的二氧化碳、水蒸气和能量交换。这项工作将在加州大学默塞德分校和劳伦斯伯克利国家实验室的资深科学家的指导下进行。

This Postdoctoral Research Fellowship supports a series of field and laboratory experiments to demonstrate the use of atmospheric carbonyl sulfide (COS) as an independent proxy for terrestrial gross primary production. Gross primary production is the total amount of carbon dioxide "fixed" by land plants per unit time through the photosynthetic reduction of carbon dioxide into organic compounds. It is an important parameter for describing carbon-climate feedbacks, assessing ecosystem-based carbon dioxide capture and storage projects, and as an important input parameter in models of ecosystem carbon exchange. This investigator is actively involved in education and outreach to promote literacy in science.To use COS exchange as an approximation of carbon uptake on an ecosystem scale, soil exchange rates of COS need to be characterized to distinguish COS plant consumption from COS uptake in soils. The investigator is developing a novel application of the isotope pool dilution technique (using 13COS) to enable measurements of soil COS consumption and production, thereby untangling factors that control net COS exchange. She will conduct controlled laboratory experiments to assess the role of environmental variables such as temperature, UV light, and enzyme activities in soils on the variations in COS exchange. Field measurements will be made at a variety of sites, including at a montane gradient in southern California that is a designated FLUXNET site and at a chaparral and a desert site that is already instrumented with eddy flux towers and continuously monitored environmental variables. FLUXNET is a regional network in which each participating site uses eddy covariance methods to measure the exchanges of carbon dioxide, water vapor, and energy between terrestrial ecosystems and the atmosphere.This work will take place under the guidance of senior scientists at the University of California Merced and the Lawrence Berkeley National Laboratory.