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

南极西部冰原（WAIS）约占整个南极冰原的10%。由于其几个出口冰川流入阿蒙森海，西海冰川目前正在失去质量。近年来，由于降雪的自然增加，这种质量损失的速度也在增加。造成这种情况的一个可能原因是该地区末端冰川向海漂浮冰架的基底融化增加。这可能是由于进入冰下带的相对温暖的环极深水（CDW）的温度或环流模式的变化，提供热量以增加基础融化速率。由于西太平洋冰架床的大部分位于海平面以下，因此在理论上是不稳定的，因此在变暖的海洋中，西太平洋冰架的稳定性和流动性引起了相当大的兴趣。从理论上讲，西洋带的完全解体可能会使全球海平面上升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）和南环模（SAM），海洋温度和洋流制度的变化，以及冰川床物理的复杂性，重要的是这些成分相互作用的时间尺度，是一项具有挑战性的建模和计算任务。来自俄亥俄州立大学、老道明大学和纽约大学的一组研究人员将为南大洋开发一个地球系统模型，并将其组成部分结合起来，重点放在南极西部地区。要耦合的组件系统模式包括大气天气研究与预报模式（Polar WRF）的极地优化版本。海洋部分将是区域海洋模拟系统（ROMS），海冰部分将是洛斯阿拉莫斯海冰模型（CICE）。将进行回溯年代际模拟，以了解最近的过去变率。全球国家大气研究中心（NCAR）社区气候模式（CCSM或同等模式）将推动对南极洲未来的缩减预估，该模式也被用于IPCC第五次评估的模拟。本提案是对CRI-EaSM征求意见的回应性提交，其目标是通过规模活动最大化利用现有观测和模式数据进行影响评估，并有效地将模式结果和相关不确定性转化为科学依据，为人类适应气候变化和管理决策提供充分的信息，特别是应对下个世纪海平面显著上升的风险。

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.