Collaborative Research: The Pan-Arctic climate and Ecosystem Response to Historical and Projected Changes in the Seasonality of Sea Ice Melt and Growth

该奖项将通过使用观测记录和地球系统模型对未来气候的预测，支持对海冰融化开始和冻结开始的季节性时间变化的原因和影响进行定量评估。该研究将综合现有的数据集，包括来自北极系统科学综合（SASS）和北极观测网络（AON）项目的结果。这将辅之以对社区气候系统模型第4版的控制和敏感性综合分析，该模型改进了极地过程和能力，包括更普遍和一致的海冰冰量表示和生态系统/海洋地球化学组成部分。具体而言，该研究将（1）调查海冰和积雪条件的季节性变化之间的相互作用和反馈，太阳辐射量以及这种辐射的分配，（2）评估这些相互作用对冰-海洋-大气热量，淡水和生物有效铁交换变化的影响，并调查它们对生态系统动力学，生物地球化学循环，和气候的CCSM，和（3）评估和最终提高地球系统模式的能力，根据这些过程，特别是通过改善与表面反射和光传输参数化的冰覆盖的海洋物理。这项研究对各种受众有许多“更广泛的影响”。研究结果将用于评估地球系统模型中北极气候和北极生态系统季节性循环的代表性，并将有助于了解北极大气-海冰-海洋-地球化学系统中关键触发事件的复杂平衡。模型模拟输出将免费提供，并有助于使用生态系统模型，包括更高的营养水平的研究，以及研究人员设计和分析观测领域的计划。研究的泛北极重点将为在特定地理位置进行的测量和研究提供背景。通过NCAR和CRREL的指导计划，两名本科生将参与该项目。这项工作的成果将通过访问当地小学，并纳入达特茅斯学院、加州欧文大学和华盛顿大学的课程，介绍给课堂。太平洋科学中心（西雅图）、伯克博物馆（西雅图）和蒙特郡博物馆（佛蒙特州）的博物馆展示将接触到传统课堂之外的更广泛的观众。

This award will support a quantitative assessment of the causes and effects of variations in the seasonal timing of sea ice melt onset and freeze initiation, through use of the observational record and earth system model projections of future climate. The study will synthesize existing datasets including results from ARCSS Synthesis of Arctic System Science (SASS) and Arctic Observing Network (AON) projects. This will be complemented by an analysis of control and sensitivity integrations from the Community Climate System Model, version 4 (CCSM4), which has improved polar processes and capabilities, including a more general and consistent sea ice albedo representation and an ecosystem/biogeochemistry component. Specifically, the study will (1) investigate interactions and feedbacks between seasonal changes in the sea ice and snow conditions, the amount of solar insolation, and the partitioning of this radiation, (2) assess the implications of these interactions for changes in ice-ocean-atmosphere heat, freshwater, and bio-available iron exchange and investigate their influence on ecosystem dynamics, biogeochemical cycling, and climate in the CCSM, and (3) evaluate and ultimately improve the capabilities of earth system models in light of these processes, specifically by improving the physics associated with surface albedo and light transmission parameterizations for ice covered seas. This study has many 'Broader Impacts' for a variety of audiences. The results will be used to assess the representation of the seasonal cycle of Arctic climate and the Arctic ecosystem in earth system models, and will aid in understanding the intricate balance of key trigger events in the Arctic atmosphere-sea ice-ocean-biogeochemical system. The model simulation output will be freely available and useful to studies using ecosystem models that include higher trophic levels, as well as to researchers designing and analyzing observational field programs. The pan-Arctic focus of the study will provide context for measurements and studies undertaken at specific geographic locations. Through mentoring programs at NCAR and CRREL, two undergraduate students will work on the project. Results from this work will be introduced to the classroom through visits to local elementary schools, and inclusion in curricula at Dartmouth College, University of California Irvine and University of Washington. Museum presentations at the Pacific Science Center (Seattle), the Burke Museum (Seattle) and the Montshire Museum (Vermont) will reach wider audiences outside of the traditional classroom.