Collaborative Research: Closing the Gaps in Climate Models' Surface Albedo Schemes of Processes Driving the Darkening of the Greenland Ice Sheet

合作研究：缩小气候模型表面反照率方案中导致格陵兰冰盖变暗的过程的差距

• 批准号: 1712695
• 负责人: Mark Flanner
• 金额: $ 10.16万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-15 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1712695&HistoricalAwards=false
• 关键词: Collaborative; Research; Closing; Gaps; Climate

Surface albedo is a measure of the percentage of solar radiation that is reflected by a medium. The higher (lower) the albedo, the lower (higher) is the amount of solar energy absorbed by the medium. Albedo plays a critical role on the Greenland Ice Sheet, where absorbed solar radiation is the dominant driver of surface melt during summer. The evolution of albedo on the Greenland Ice Sheet is primarily driven by changes in snow grain size, the presence of liquid water on the surface, the exposure of bare ice, and the presence of light-absorbing impurities in the snow and ice. Such impurities include soot, dust, and biological constituents like bacteria and algae. Interactions between biological impurities and snow physical processes (e.g., metamorphism and melt redistribution) are important because they can drive positive feedbacks in which total melt is amplified. Despite their importance, these processes relating biological constituents to snow and ice evolution are currently either absent or poorly represented in models used to simulate current estimates and future projections of the contribution of Greenland to sea level rise. Through an interdisciplinary and collaborative effort, this project will integrate state of the art knowledge of how biological activity impacts albedo into climate models. This will help reduce uncertainties of the contribution of Greenland to sea level rise and will also improve our understanding of interactions between the ice sheet and the atmosphere.The regional climate and Earth System models that will be applied in our study are open-source models, such as e.g., the Community Earth System Model). Model improvements that are implemented will be released for use by other researchers in a timely way. The project includes the involvement of a postdoctoral fellow, and hence training of young investigators to address complex and yet crucial science questions through an interdisciplinary effort. Results from this project will be communicated to the media and public, thereby promoting deeper knowledge of the processes affecting the surface mass balance of the Greenland Ice Sheet.

表面反照率是介质反映的太阳辐射百分比的量度。反照率较高（较低），较低（较高）是介质吸收的太阳能量。反照圈在格陵兰冰盖上起着至关重要的作用，在夏季，吸收的太阳辐射是表面熔体的主要驱动力。雪粒尺寸的变化，表面上存在液态水，裸露的冰的暴露以及在雪和冰中存在降低光杂质的情况，反照率在格陵兰冰盖上的演变主要是由雪粒尺寸的变化，液态水的存在驱动的。 这种杂质包括烟灰，灰尘和生物成分，例如细菌和藻类。 生物杂质与雪物理过程之间的相互作用（例如变质和熔体再分配）很重要，因为它们可以驱动放大总熔体的积极反馈。尽管它们的重要性，但这些过程与雪和冰的演化有关的这些过程目前在用于模拟格陵兰对海平面上升的贡献的当前估计和未来预测的模型中目前不存在或不良代表。通过跨学科和协作的努力，该项目将整合有关生物活动如何影响反照率进入气候模型的艺术状态。这将有助于减少格陵兰对海平面上升的贡献的不确定性，还将提高我们对冰盖与大气之间的相互作用的理解。我们研究将应用的区域气候和地球系统模型是开源模型，例如社区地球系统模型）。实施的模型改进将及时发布其他研究人员。该项目包括一名博士后研究员的参与，并因此培训了年轻的研究人员，以通过跨学科的工作来解决复杂而又至关重要的科学问题。该项目的结果将传达给媒体和公众，从而提高了影响格陵兰冰盖表面质量平衡的过程的深入了解。

项目成果

SNICAR-ADv4: a physically based radiative transfer model to represent the spectral albedo of glacier ice

SNICAR-ADv4：基于物理的辐射传输模型，用于表示冰川冰的光谱反照率

• DOI: 10.5194/tc-16-1197-2022
• 发表时间: 2022
• 期刊: The Cryosphere
• 作者: Whicker, Chloe A.;Flanner, Mark G.;Dang, Cheng;Zender, Charles S.;Cook, Joseph M.;Gardner, Alex S.
• 通讯作者: Gardner, Alex S.

SNICAR-ADv3: a community tool for modeling spectral snow albedo

• DOI: 10.5194/gmd-14-7673-2021
• 发表时间: 2021-12-21
• 期刊: GEOSCIENTIFIC MODEL DEVELOPMENT
• 影响因子: 5.1
• 作者: Flanner, Mark G.;Arnheim, Julian B.;Zender, Charles S.
• 通讯作者: Zender, Charles S.