The Response of Arctic Clouds to Changes in Sea Ice during Autumn

秋季北极云对海冰变化的响应

• 批准号: 1021274
• 负责人: Axel Schweiger
• 金额: $ 55.13万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1021274&HistoricalAwards=false
• 关键词: Response; Arctic; Clouds; Changes; Sea

Clouds play a major role in the arctic surface energy balance controlling the growth and melt of sea ice. At the same time the processes involved in the formation, maintenance and dissipation of cloud cover over the Arctic Ocean are thought to be strongly influenced by the sea ice itself. The proposed project will advance the understanding of this interaction and feedback by asking: What is the response of Arctic clouds to diminishing sea ice? In answering this question, the PI's will consider (i) the physical processes that cause and modulate this response, (ii) the role of large-scale atmospheric dynamics, (iii) the potential effects on the heat and energy balance and in climate feedbacks, and (iv) the limitations of observing from space the response of clouds to changes in sea ice. The approach will be to conduct a series of experiments with different configurations of a regional atmospheric model, the Weather Research and Forecast (WRF) model. Focusing on the autumn season, sea ice and sea surface temperature will be altered and changes in cloud cover associated with sea ice will be examined in the context of large scale dynamics. Model experiments designed to better understand the physical processes involved in the response of clouds to diminishing sea ice will be performed. The impact on the surface and the top of the atmosphere energy balance of sea-ice driven changes on cloud cover and the atmospheric temperature and humidity will be examined. Differences in sea ice-cloud interactions between the WRF model and a typical global climate model (e.g. CAM) will be assessed. Finally, satellite cloud detection criteria used in typical visible and infrared-based algorithms will be evaluated for their ability to properly detect cloud changes in the context of significant changes in surface properties by performing radiative transfer calculations to simulate the spectral signal at the satellite from modeled atmospheric and cloud responses for different surface conditions. This research will address significant questions of the ?Understanding Change? aspect of the Study of Arctic Environmental Change (SEARCH). In particular the questions/activities "What are the critical interactions among ocean, ice, land, and atmosphere as they relate to Arctic Change?", "What is the direction and relative importance of feedbacks?" will benefit from this analysis.

云在控制海冰生长和融化的北极表面能量平衡中发挥着重要作用。 与此同时，北冰洋上空云层的形成、维持和消散过程被认为受到海冰本身的强烈影响。 拟议的项目将通过询问以下问题来增进对这种相互作用和反馈的理解：北极云对海冰减少有何反应？在回答这个问题时，PI 将考虑 (i) 引起和调节这种响应的物理过程，(ii) 大规模大气动力学的作用，(iii) 对热量和能量平衡以及气候反馈的潜在影响，以及（iv）从太空观测云对海冰变化的响应的局限性。 该方法将利用区域大气模型、天气研究和预报（WRF）模型的不同配置进行一系列实验。 重点关注秋季，海冰和海面温度将发生变化，并将在大尺度动态背景下研究与海冰相关的云量变化。 将进行模型实验，旨在更好地了解云对海冰减少的反应所涉及的物理过程。将研究海冰驱动的云量变化以及大气温度和湿度对地表和大气层顶部能量平衡的影响。 将评估 WRF 模型和典型全球气候模型（例如 CAM）之间海冰-云相互作用的差异。最后，将评估典型的基于可见光和红外的算法中使用的卫星云检测标准，通过执行辐射传输计算来模拟卫星上的光谱信号，以评估其在表面特性显着变化的情况下正确检测云变化的能力。大气和云对不同表面条件的响应。这项研究将解决“理解变革”的重要问题。北极环境变化研究（SEARCH）的一个方面。 特别是问题/活动“海洋、冰、陆地和大气之间与北极变化相关的关键相互作用是什么？”、“反馈的方向和相对重要性是什么？”将从该分析中受益。