Collaborative Research: Polynyas in Coastal Antarctica (PICA): Linking Physical Dynamics to Biological Variability

在冬季，南极海岸的海冰覆盖被众多的冰裂湖所打断，这些冰裂湖是几十到几百公里宽的孤立开口。这些沿海多冰区是海冰产生的热点地区，也是全球海洋底水的主要来源地区。它们还承载着高水平的生物活动，是帝企鹅和海洋哺乳动物的觅食地。多冰湖是南极海岸系统的重要组成部分，对企鹅和许多其他物种的生存至关重要。这些特征在形成时间、持续时间、浮游植物生长季节和总体生物生产力方面也存在显著差异。然而，它们之间差异的根本原因在很大程度上是未知的。本项目研究了各种冰礁的基本生物物理过程，探讨了物理环境与浮游植物和企鹅生态之间的联系，并探讨了冰礁变异性的机制。本跨学科研究的结果将为南极海岸冰湖的野外测量解释提供一个背景，为未来的冰湖研究设定基线，并研究冰湖生态系统如何响应局部和大规模的环境变化。该项目将包括向广大受众传达科学信息的教育和推广活动。它的目的是提高公众对大规模环境变化与南极海岸系统之间相互联系的认识。本研究的主要目的是全面了解南极海岸融冰的时空变异性和融冰生态系统的物理控制。该项目采用跨学科的方法，并寻求建立一个以区域海洋模拟系统为中心的建模系统。这个系统将冰和海洋状况与浮游生物生态和企鹅数量联系起来。结合对现有观测结果的分析，在有代表性的冰湖中应用模拟系统，将确定个别强迫因素的生物物理影响。特别地，本研究将测试风、近海海水入侵、冰架融化、海冰形成、冰川舌和海洋分层对多冰湖浮游植物繁殖时间和整体多冰湖生物生产力的一系列假设影响。该项目还将研究冰沼状态的变化如何影响企鹅繁殖成功、成虫生存和种群增长。该小组将进行理想化的敏感性分析，以探索强迫变率对南极沿海生态系统的影响，包括局部和大规模的环境变化。

During winter, sea-ice coverage along the Antarctic coast is punctuated by numerous polynyas--isolated openings of tens to hundreds of kilometer wide. These coastal polynyas are hotspots of sea ice production and the primary source regions of the bottom water in the global ocean. They also host high levels of biological activities and are the feeding grounds of Emperor penguins and marine mammals. The polynyas are a key component of the Antarctic coastal system and crucial for the survival of penguins and many other species. These features also differ dramatically from each other in timing of formation, duration, phytoplankton growth season, and overall biological productivity. Yet, the underlying reasons for differences among them are largely unknown. This project studies the fundamental biophysical processes at a variety of polynyas, examines the connection between the physical environment and the phytoplankton and penguin ecology, and investigates the mechanisms behind polynya variability. The results of this interdisciplinary study will provide a context for interpretation of field measurements in Antarctic coastal polynyas, set a baseline for future polynya studies, and examine how polynya ecosystems may respond to local and large-scale environmental changes. The project will include educational and outreach activities that convey scientific messages to a broad audience. It aims to increase public awareness of the interconnection between large-scale environmental change and Antarctic coastal systems.The main objectives of this study are to form a comprehensive understanding of the temporal and spatial variability of Antarctic coastal polynyas and the physical controls of polynya ecosystems. The project takes an interdisciplinary approach and seeks to establish a modeling system centered on the Regional Ocean Modeling System. This system links the ice and ocean conditions to the plankton ecology and penguin population. Applications of the modeling system in representative polynyas, in conjunction with analysis of existing observations, will determine the biophysical influences of individual forcing factors. In particular, this study will test a set of hypothesized effects of winds, offshore water intrusion, ice-shelf melting, sea-ice formation, glacier tongues, and ocean stratification on the timing of polynya phytoplankton bloom and the overall polynya biological productivity. The project will also examine how changing polynya state affects penguin breeding success, adult survival, and population growth. The team will conduct idealized sensitivity analysis to explore implications of forcing variability, including local and large-scale environmental change, on Antarctic coastal ecosystems.