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范围被许多冰川--几十到数百公里宽的孤立开口--所打断。这些沿海冰川是海冰产生的热点，也是全球海洋底层水的主要来源区域。它们还拥有高水平的生物活动，是帝企鹅和海洋哺乳动物的觅食场所。多尼雅是南极海岸系统的关键组成部分，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整体生物生产力方面也有很大不同。然而，他们之间存在差异的根本原因在很大程度上是未知的。该项目研究了各种多年生生物的基本生物物理过程，考察了物理环境与浮游植物和企鹅生态之间的联系，并调查了多年生生物多样性背后的机制。这项跨学科研究的结果将为解释南极沿海波尼亚的实地测量提供背景，为今后的波尼亚研究设定基线，并审查波尼亚生态系统如何应对当地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外联活动。它旨在提高公众对大范围环境变化与南极沿海系统之间相互联系的认识。这项研究的主要目的是对南极沿海多尼雅生态系统的时间和空间变异性以及多尼亚生态系统的物理控制形成全面的了解。该项目采取跨学科方法，力求建立一个以区域海洋模式系统为中心的模式系统。这个系统将冰层和海洋状况与浮游生物生态和企鹅种群联系起来。将模拟系统应用于具有代表性的波利尼亚，结合对现有观测的分析，将确定个别强迫因素的生物物理影响。特别是，这项研究将测试一组假设的风、近海水域入侵、冰架融化、海冰形成、冰川舌头和海洋层化对多尼亚浮游植物水华发生的时间和整个多尼亚生物生产力的影响。该项目还将研究多尼雅状态的变化如何影响企鹅的繁殖成功、成体存活和种群增长。该小组将进行理想化的敏感性分析，以探索强迫变化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.