Collaborative Research: Uncertainty in Antarctic Climate Change Projections and the Role of Sea Ice, Clouds and Ocean Structure

南极洲和南大洋的气候变化在全球海平面上升、海洋碳储存和热量输送方面具有重大的社会影响。本研究的项目目标是使用最先进的群落气候模式（CESM）系统地评估长期大气辐射和海洋结构成分对模拟的南极洲和南大洋气候的影响。该项目将由科罗拉多大学（CU）和国家大气研究中心（NCAR）的女性pi共同领导，并将支持科罗拉多大学（CU）的一名新研究生和一名科学传播博士后的培训和指导。由于公众对这些问题的理解可能非常低，因此该项目包括大量的外展和科学传播组成部分。将开发一个互动式博物馆展示，展示南极海冰趋势和变化的解释和含义，同时为全国K-12教育工作者提供培训，重点是使用该展示或网络变体。预估的人为气候变化影响的很大不确定性与南极洲和南大洋有关。当前气候模式对南极表面物质平衡、海冰范围和表面温度的预估变化差异很大。这种不确定性可能源于不同模式的平均状态（气候学）。最近的观测和模式证据暗示了海洋平均状态偏差，特别是气候模式普遍无法模拟遥感观测到的南极海冰年度范围的趋势。海洋偏倚的部分原因可能是南大洋上空吸收的短波辐射长期存在的偏倚。该项目的主要目标是利用最先进的群落气候模式（CESM）系统地评估长期存在的大气辐射和海洋结构偏差对模拟的南极洲和南大洋气候的影响。预计平均状态（气候学）偏差的减少将改变海冰范围和体积、气温、降水、地表物质平衡和海平面上升对人为强迫的响应。拟议的气候模拟实验，连同现有的数值模拟实验，将使我们能够比以前更全面、更系统地评估平均状态偏差对模拟南极洲和南大洋气候变率和变化的影响。

Climate change in Antarctica and the Southern Ocean has major societal impacts in terms of global sea level rise, carbon storage into the ocean, and heat transport. The project goal of this study is to systematically assess the influence of long-standing atmospheric radiation and ocean structure components on the modelled climate of Antarctica and the Southern Ocean, using a state-of-the-art community climate model (CESM). The project will be co-led by female PIs at the University of Colorado (CU) and National Center for Atmospheric Research (NCAR), and will support the training and mentoring of a new graduate student at CU, and a science communication postdoc. Because public understanding of these issues can be very low, the project includes a substantial outreach and science communication component. An interactive museum display demonstrating the interpretation and implications of trends and variability in Antarctic sea ice will be developed, along with provision of training for K-12 educators nationwide that focuses on using the display, or a web variant.Large uncertainties in projected anthropogenic climate change impacts are related to Antarctica and the Southern Ocean. Projected changes in Antarctic surface mass balance, sea ice extent, and surface temperature differ widely amongst current-generation climate models. Such uncertainties likely have roots in the mean states (climatologies) of different models. Recent observational and modeling evidence has implicated ocean mean-state biases in particular for the general inability of climate models to simulate trends in annual Antarctic sea ice extent observed by remote sensing. Ocean biases may be driven in part by a long-standing bias in absorbed shortwave radiation over the Southern Ocean. The primary project goal is to systematically assess the influence of long-standing atmospheric radiation and ocean structure biases on the modelled climate of Antarctica and the Southern Ocean, using a state-of-the-art community climate model (CESM). It is anticipated that the mean state (climatology) bias reductions will alter the response of sea ice extent and volume, air temperature, precipitation, surface mass balance, and sea level rise to anthropogenic forcing. Proposed climate modeling experiments, together with existing numerical simulation experiments, will enable a more thorough and systematic assessment of the impact of mean-state biases on the simulation of climate variability and change across Antarctica and the Southern Ocean than has been previously possible.