Type 1-L02170391: Collaborative Research: Atmosphere-Ocean Coupling Causing Ice Shelf Melt in Antarctica (ACCIMA)

西南极冰盖（WAIS）约占整个南极冰盖的10%。由于几个出口冰川流入阿蒙森海，WAIS目前正在失去质量。近年来，这种质量损失的速度，超过了通过降雪自然增长的速度，也在增加。其中一个可能的原因是该地区终端冰川的向海浮冰架底部融化增加。这可能是由于温度或环流模式的变化，相对温暖的环极深水（CDW）进入冰下区，提供热量以增加基础融化率。由于大部分的WAIS床位于海平面以下，因此在理论上是不稳定的，有相当大的兴趣在其稳定性和流动性的WAIS冰架在一个温暖的海洋。 WAIS的完全解体原则上可以使全球海平面上升4.8米。了解大尺度大气环流模式的耦合，如厄尔尼诺南方涛动（ENSO）和南方环形模式（SAM），海洋温度和电流制度的变化，沿着冰川床物理的复杂性，重要的是这些组件相互作用的时间尺度是一个具有挑战性的建模和计算任务。来自俄亥俄州、旧自治领大学和纽约大学的一个研究小组将开发和耦合南大洋地球系统模型的组成部分，重点放在南极西部。要耦合的组成系统模型包括大气层天气研究和预报模型（极地WRF）的极地优化版本。海洋部分将是区域海洋模拟系统，海冰部分将是洛斯阿拉莫斯海冰模型。将进行回顾性十年模拟，以了解最近的变化。全球国家大气研究中心（NCAR）社区气候模型将推动对南极洲未来的缩小预测（CCSM或其同等产品），这也被用于IPCC第五次评估模拟。本提案是对CRI的回应，EaSM征集的目标是通过缩放活动最大限度地利用现有的观测和模型数据进行影响评估，将模型结果和相关的不确定性转化为科学依据，以便人类在充分知情的情况下适应气候变化并作出管理决定，特别是应对下一个世纪海平面大幅上升的风险。

The West Antarctic Ice Sheet (WAIS) represents about 10% of the entire Antarctic ice sheet. The WAIS is currently losing mass due to several of its outlet glaciers draining into the Amundsen Sea. The rate of this mass loss, over natural accretion through snowfall, has also been increasing in recent years. One possible reason for this is increased basal melt of the seaward floating ice shelves of the region's terminal glaciers. This can result from a change in either the temperature, or circulation patterns, of the relatively warm Circumpolar Deep Water (CDW) that enters the subglacial zone, providing heat to increase the basal melt rate. Because much of the WAIS bed lies well below sea-level and is therefore theoretically unstable, there is considerable interest in its stability and mobility of the WAIS ice shelves in a warming ocean. Complete disintegration of the WAIS could in principle raise global sea levels by as much as 4.8 m. Understanding the coupling of large scale atmospheric circulation patterns such as the El-Nino Southern Oscillation (ENSO) and the Southern Annular Mode (SAM), changes in ocean temperature and current regimes, along with the complexity of glacial bed physics and importantly the timescales over which these components interact is a challenging modeling and computational task. A team of researchers from Ohio State, Old Dominion University and NYU will develop and couple components of an earth systems model for the Southern Ocean with a regional emphasis on the West Antarctic. The component system models to be coupled include the polar-optimized version of the Weather Research and Forecasting model (Polar WRF) for the atmosphere. The ocean component will be the Regional Ocean Modeling System (ROMS), and the sea ice component will be the Los Alamos sea ice model (CICE). Retrospective decadal simulations will be done to understand recent past variability. Downscaled future projections for Antarctica will be driven by the global National Center for Atmospheric Research (NCAR) Community Climate Model (CCSM or its equivalent), which is also being used for the IPCC 5th Assessment simulations.This proposal is a responsive submission to the CRI-EaSM solicitation with goals to maximize the utility of available observational and model data for impact assessments through scaling activities and to effectively translate model results and associated uncertainties into the scientific basis for well-informed human adaptation to and management decisions for climate change, specifically addressing the risk of significant sea-level rise in the next century.