Projeto de pesquisa

Marine primary productivity controls ocean food webs and biogeochemical cycles, exerting a strong influence on CO2 uptake from the atmosphere and global climate. Unprecedented anthropogenic pressure has created an urgent need to understand environmental controls on primary productivity. This, in turn, relies on consistent and coherent measurements across a range of spatial and temporal scales. Productivity estimates from conventional 14C-uptake experiments require discrete bottle sampling (and suffer potential experimental artefacts), while those from mixed layer dissolved gas measurements (O2, CO2 etc.) do not directly measure gross photosynthesis, and lack the temporal resolution needed to validate daily remote-sensing observations. Active chlorophyll a (Chla) fluorescence-based measurements can overcome these challenges. First introduced several decades ago, techniques such as Fast Repetition Rate fluorometry have significantly advanced our understanding of environmental controls on phytoplankton physiology and productivity. However, rapidly growing capacity to engineer and deploy sea-going fluorometers now poses a major time-sensitive challenge: Conceptual, operational and computational approaches to extract and interpret fluorescence parameters are rapidly diverging. While an increasing number of (often custom-built) sensors, protocols and processing algorithms is being produced, no standard best practices have been formally adopted by the research community. Rapidly growing data sets may thus become increasingly difficult (perhaps impossible) to reconcile, thereby limiting our capacity to integrate observations over large-scales. This SCOR working group will address this challenge by producing international standards for best-practices in the acquisition and interpretation of active Chl fluorescence data, while also creating a framework for a global synthesis of existing and future data.