Patterns and processes of primary productivity and trace gas dynamics in subpolar and polar oceans

点击翻译按钮获取中文摘要

Marine primary productivity (the photosynthetic conversion of CO2 to carbohydrates) provides the energy and carbon needed to support the vast majority of ocean ecosystems, and plays a direct role in regulating Earth's climate through the uptake and emission of trace gases, including CO2, methane (CH4), nitrous oxide (N2O) and dimethylsulfide (DMS), which influence the planet's heat budget. Polar and sub-polar marine waters contribute disproportionately to ocean primary productivity, and are experiencing the greatest impacts of global climate change. The long-term objective of this research program is to understand the factors regulating marine primary productivity and climate-active gas cycling in polar and sub-polar regions. To inform this goal, the short-term objectives of this research program are to: 1) deploy autonomous ship-based instruments to examine variability in primary productivity, and trace gas concentrations in the Subarctic Pacific and Arctic Oceans, and examine the underlying processes driving this variability; 2) use field observations and laboratory experiments to examine environmental controls on different aspects of the photosynthetic process, including light absorption, photosynthetic electron transport, oxygen evolution, and carbon fixation; and 3) develop statistical algorithms and improved numerical models of ocean primary productivity and trace gas emissions. The research will be accomplished using controlled laboratory experiments and oceanographic sampling on board research vessels and at coastal marine stations. Building on our recent progress developing automated ship-board sensors, we will deploy a wide range of instrumentation to measure surface ocean optical properties, dissolved gas concentrations and other oceanographic variables over a range of space and time-scales, and in response to experimental manipulations. Results from this work will be used to train machine learning algorithms and develop improved ocean biogeochemical models. Anticipated impacts include enhanced understanding of the space and time variability of marine productivity and climate-active gas emissions, and new insight into the environmental and physiological factors controlling this variability. This information will, in turn, support the development of improved numerical models predicting marine ecological and biogeochemical responses to future climate warming. The research program will train HQP in a supportive and inclusive environment, providing them with advanced technical skills, and communication and outreach tools to mobilize knowledge and support the sustainable development of Canada's ocean economy.