Using high precision dissolved gas measurements to constrain the ocean carbon cycle

大气中二氧化碳的持续增加及其对气候的潜在影响，使得了解碳在环境不同部分之间的移动方式对我们的社会至关重要。海洋拥有我们气候系统中的大部分碳，由于生物和物理过程，深海的碳浓度自然比表面高得多。深海中更多的碳意味着大气中更少的碳。我的研究项目侧重于将碳输送到深海的生物和物理过程。我使用的工具是高精度的溶解气体测量。首先，我们将对没有生物作用的气体(惰性气体，如霓气、氩、氪和氙气)进行测量，以确定温度变化、大气-海洋气体交换和大气压力等物理过程如何影响海洋中的任何气体。这些测量将与气候模型的预测进行比较，以改进包括二氧化碳在内的溶解气体的模型过程。其次，我们将对氧及其同位素进行测量，以确定海洋生产力(光合作用和呼吸作用)的速率。这些测量将告诉我们海洋生态系统吸收二氧化碳并以颗粒的形式将其发送到深海的效率。这些测量还将与基于瓶子中海水培养的传统方法进行比较，以了解两种方法之间的差异和各自的不确定度。第三，我们将对溶解氮气进行测量，以确定从海洋中去除硝酸盐和氨等营养物质的情况。海洋中营养物质的总量(主要是浮游生物肥料)最终可以控制海洋生产力，因此我们必须了解从海洋中去除营养物质的过程。总之，这些研究将帮助我们了解碳在海洋中移动的方式，并更好地预测未来的变化。对未来海洋和大气二氧化碳浓度的更好预测将使加拿大人受益，因为它提供了更清晰的标准，供政府代表就能源使用和气候变化缓解战略做出决定。

The continuing increase in atmospheric carbon dioxide and its potential to affect our climate have made understanding the way carbon moves between different parts of the environment of utmost importance to our society. The ocean holds most of the carbon in our climate system, with the deep ocean naturally containing far higher carbon concentration than the surface due to both biological and physical processes. More carbon in the deep ocean means less in the atmosphere. My research program focuses on the biological and physical processes that send carbon to the deep ocean. The tools I use are high precision measurements of dissolved gases. First, we will make measurements of gases with no biological role (inert gases like neon, argon, krypton, and xenon) to determine how physical processes like temperature change, air-sea gas exchange, and atmospheric pressure affect any gas in the ocean. These measurements will be compared to the predictions of climate models to improve model processes for dissolved gases, including carbon dioxide. Second, we will make measurements of oxygen and its isotopes to determine the rate of ocean productivity (photosynthesis and respiration). These measurements will tell us the efficiency with which ocean ecosystems take up carbon dioxide and send it to the deep ocean in the form of particles. These measurements will also be compared to traditional methods based on incubations of seawater in bottles to understand the differences between methods and the uncertainties in each. Third, we will make measurements of dissolved nitrogen gas to determine the removal of nutrients like nitrate and ammonia from the ocean. The total amounts of nutrients in the ocean (essentially plankton fertilizer) can ultimately control ocean productivity, so we must understand the processes that remove nutrients from the ocean. Together these studies will help us to understand the way that carbon moves through the ocean and to better predict future changes. Better predictions of future ocean and atmospheric carbon dioxide concentrations will benefit Canadians by providing clearer criteria on which government representatives can make decisions regarding energy use and climate change mitigation strategies.