Characteristics of the Summer Arctic Frontal Zone Atmospheric Feature and Its Projected Changes through the 21st Century

夏季北极锋区大气特征及其预计的21世纪变化

• 批准号: 1417016
• 负责人: Mark Serreze
• 金额: $ 47.58万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1417016&HistoricalAwards=false
• 关键词: Characteristics; Summer; Arctic; Frontal; Zone

NontechnicalThis project will explore the characteristics, variability and environmental impacts of a little-studied arctic seasonal atmospheric feature called the Summer Arctic Frontal Zone (AFZ), and how it may change over the next century. Little is known about variability in the AFZ or how it will change in the future. The feature is overlain by a high level jet-like feature, and areas where the AFZ are most pronounced are regions of frequent storm genesis, so understanding it is important to understand and predict weather events. In linking the arctic atmosphere, ocean, land surface and the hydrologic cycle, this study of the AFZ adopts a systems perspective, and steeping the next generation of researchers in systems studies is important for maintaining U.S. preeminence in environmental science, so the project is strongly geared towards support of a graduate student. Results from this study will be integrated into university classes and results will be featured in the National Snow and Ice Data Center?s Monthly Highlights. To communicate climate research to the general public, datasets created for this research will be formatted for Science on a Sphere technology. A research team member and the graduate student will present these data and their significance to the public as a part of science outreach shows at the University of Colorado?s Fiske Planetarium.TechnicalThis is an effort to take advantage of data from a suite of advanced atmospheric reanalyses, satellite remote sensing and model experiments to address the characteristics, variability and environmental impacts of the Summer Arctic Frontal Zone (AFZ), and how this seasonal feature may change over the next century. Most prior research concludes that the AFZ develops primarily in response to summer heating contrasts between the Arctic Ocean and snow-free land. The AFZ is best developed along the Eurasian and Alaskan coasts, especially in Eastern Siberia and north of Alaska's Brooks Range, where it appears that temperature gradients are sharpened by topographic trapping of cold Arctic Ocean air. The AFZ at the surface is overlain by a jet-like feature at the tropopause. Areas where the AFZ are best expressed are regions of frequent cyclogenesis, and these cyclones have significant impacts on the summer precipitation regime not only along the Arctic coast, but also over the central Arctic Ocean, which is where many of the lows migrate into and decay. Migration of cyclones into the central Arctic Ocean also likely influences the sea ice state. This study will focus on: how seasonal development of the AFZ relates to variations in the seasonal timing of snow-free conditions over land, the location of the sea ice margin, surface temperatures, and topography; whether there is support for persisting views of ecological controls on the AFZ; how different patterns of atmospheric circulation influence the expression of AFZ; how variability in the AFZ is expressed in terms of patterns of cyclogenesis and summer precipitation; and how the AFZ will change through the 21st century in response to changes in seasonal snow cover, sea ice conditions and potential changes in atmospheric circulation patterns. The study will employ data from three atmospheric reanalyses, sea ice extent from the satellite passive microwave record, Reynolds sea surface temperature, satellite-derived terrestrial snow cover extent, experiments with the Weather Research and Forecasting regional model and output from coupled global models.

这个项目将探索被称为夏季北极锋面区（AFZ）的一个鲜为人知的北极季节性大气特征的特征、可变性和环境影响，以及它在下个世纪将如何变化。人们对AFZ的可变性知之甚少，也不知道它将来会如何变化。该特征被一个类似高空急流的特征覆盖，AFZ最明显的地区是风暴频发的地区，因此了解AFZ对于理解和预测天气事件非常重要。在将北极大气、海洋、陆地表面和水文循环联系起来的过程中，AFZ的研究采用了系统的视角，让下一代研究人员参与系统研究对于保持美国在环境科学方面的卓越地位非常重要，因此该项目强烈倾向于研究生的支持。这项研究的结果将被整合到大学课程中，结果将在国家冰雪数据中心展出。每月亮点。为了向公众传达气候研究，为此研究创建的数据集将被格式化为“科学在一个球体”技术。一名研究小组成员和一名研究生将向公众展示这些数据及其意义，作为科罗拉多大学科学推广展览的一部分。菲斯克天文馆。这是一项利用一套先进的大气再分析、卫星遥感和模式实验的数据来解决夏季北极锋区（AFZ）的特征、变化和环境影响的努力，以及这种季节性特征在下个世纪可能发生的变化。大多数先前的研究得出结论，北极冷区的发展主要是对北冰洋和无雪陆地之间夏季加热差异的反应。沿欧亚和阿拉斯加海岸，特别是东西伯利亚和阿拉斯加的布鲁克斯山脉北部，AFZ最发达，那里的温度梯度似乎因北冰洋冷空气的地形捕获而变得尖锐。在对流层顶，表面的AFZ被一个类似喷流的特征覆盖。AFZ表现最好的地区是频繁发生气旋的地区，这些气旋不仅对北极沿岸的夏季降水制度有重大影响，而且对北冰洋中部的夏季降水制度也有重大影响，这是许多低压迁移和衰减的地方。气旋向北冰洋中部的迁移也可能影响海冰状况。这项研究将集中在：AFZ的季节性发展如何与陆地上无雪条件的季节性时间变化、海冰边缘的位置、表面温度和地形有关；是否有人支持对隔离区进行生态管制的观点；不同的大气环流模式对AFZ的影响；AFZ的变率如何用气旋形成和夏季降水的模式来表达；以及在整个21世纪，AFZ将如何随着季节积雪、海冰状况和大气环流模式的潜在变化而变化。该研究将采用三项大气再分析数据、卫星无源微波记录的海冰范围、雷诺兹海面温度、卫星导出的陆地积雪范围、天气研究与预报区域模式实验以及耦合全球模式输出的数据。