Antarctic phytoplankton in response to environmental change studied by a synergistic approach using multi- and hyper-spectral satellite data

气候模式表明，在不久的将来，由于对流层释放温室气体，特别是化石燃料燃烧产生的二氧化碳，南大洋将受到温度和pH值变化的显著影响和影响。这种变化将影响浮游植物的组成，从而影响碳、氮和相关化合物的循环。本跨学科项目的目标是评估南大洋浮游植物类型的时空变化，以更好地了解它们在南大洋生态系统中的差异，并改进我们对南极浮游植物对全球碳循环贡献的定量估计。利用两种不同卫星仪器的独特数据组合，将首次评估具有合理时空覆盖范围的南大洋不同浮游植物类型的浓度。这种协同方法将是通用的，并适用于即将进行的类似卫星任务，从而确保对覆盖数十年的独特浮游植物类型数据集的看法。浮游植物总生物量数据将通过多光谱成像仪器适应南极条件来获取，而最重要的浮游植物类型在总生物量中的比例将通过高光谱卫星测量的特征吸收特征分析来确定，采用我们研究小组开发的PhytoDOAS方法。由此产生的长期卫星数据集是未来变化的必要基准。然后，它将被用于研究南极浮游植物在过去十年的变化及其与变化的环境因素的相关性。此外，我们的浮游植物组成数据集将用于评估南大洋生态系统模型的性能，该模型基于模拟海洋中浮游植物的生理特征来评估其生物地理学。改进模型参数化的建议将从这项研究中得出。有了这一长期浮游植物类型数据集和已获得的南极浮游植物变异性知识，我们将有一个评估气候变化对南大洋影响的基础。

Climate models indicate that the Southern Ocean will significantly be affected and impacted by changes in temperature and pH in the near future resulting from the tropospheric release of greenhouse gases and in particular carbon dioxide from fossil fuel combustion. Such changes will impact on the phytoplankton composition and thus affect the cycling of carbon, nitrogen and related compounds. The objectives of this interdisciplinary project are to assess the spatial and temporal variability of phytoplankton types in the Southern Ocean, to better understand their different in the Southern Ocean ecosystem, and to improve our quantitative estimates of the contribution of Antarctic phytoplankton to the global carbon cycle. Using a unique combination of data from two different satellite instruments, the concentration of different phytoplankton types will be assessed for the first time in the Southern Ocean with reasonable temporal and spatial coverage. This synergistic method will be generic and applicable to similar upcoming satellite missions and therefore secure a perspective for a unique phytoplankton type data set covering decades. The total phytoplankton biomass data will be retrieved by adaptation to the Antarctic conditions from multi-spectral imaging instruments, whereas the fractions of the most important phytoplankton types within the total biomass will be determined from the analysis of their characteristic absorption features in hyper-spectral satellite measurements using the PhytoDOAS method developed by our research team. The resulting long term satellite data set is a necessary benchmark for future change. It will then be used to study the Antarctic phytoplankton varibility over the last ten years and their correlation with changing environmental factors. In addition, our phytoplankton composition data set will be used to evaluate in the Southern Ocean the performance of a ecosystem model which assesses the biogeography of phytoplankton types based on their physiological traits in a modeled ocean. Recommendations for improved model parameterizations will result from this research exercise. With this long-term phytoplankton type data set and the acquired knowledge of Antarctic phytoplankton variability, we will have a basis to assess the influence of climate change on the Southern Ocean.