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.

非技术性该项目将探索很少被研究的北极季节性大气特征（称为夏季北极锋区（AFZ））的特征、变化和环境影响，以及它在下个世纪可能发生的变化。人们对 AFZ 的变化或未来将如何变化知之甚少。该特征被高空喷射状特征覆盖，AFZ 最明显的区域是风暴频繁发生的区域，因此了解它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时，AFZ 的这项研究采用了系统视角，让下一代研究人员深入系统研究对于保持美国在环境科学领域的领先地位非常重要，因此该项目大力支持研究生。这项研究的结果将被纳入大学课程，并且结果将出现在国家冰雪数据中心的每月亮点中。为了向公众传达气候研究，为此研究创建的数据集将针对球体科学技术进行格式化。研究小组成员和研究生将向公众展示这些数据及其重要性，作为科罗拉多大学菲斯克天文馆科学推广活动的一部分。技术这是一项利用一系列先进大气再分析、卫星遥感和模型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，以及这种季节性特征如何影响的努力。 下个世纪的变化。大多数先前的研究得出的结论是，AFZ 的发展主要是为了应对夏季北冰洋和无雪陆地之间的加热对比。 AFZ 沿欧亚和阿拉斯加海岸发展得最好，特别是在东西伯利亚和阿拉斯加布鲁克斯山脉北部，那里的温度梯度似乎因北冰洋冷空气的地形捕获而加剧。地表的 AFZ 被对流层顶的喷射状特征所覆盖。 AFZ最明显的区域是气旋发生频繁的区域，这些气旋不仅对北冰洋沿岸的夏季降水状况有重大影响，而且对北冰洋中部的夏季降水状况也有显着影响，而北冰洋中部正是许多低气压迁移和衰减的地方。气旋迁移到北冰洋中部也可能影响海冰状态。这项研究将重点关注： AFZ 的季节性发展与陆地无雪条件的季节性时间变化、海冰边缘的位置、表面温度和地形有何关系；是否有人支持对AFZ进行生态控制的持续观点；不同的大气环流模式如何影响 AFZ 的表达； AFZ 的变化如何通过气旋发生和夏季降水的模式来表达；以及 AFZ 将如何在 21 世纪发生变化，以应对季节性积雪、海冰状况和大气环流模式的潜在变化。该研究将利用来自三项大气再分析的数据、卫星被动微波记录的海冰范围、雷诺海面温度、卫星得出的陆地积雪范围、天气研究和预报区域模型的实验以及耦合全球模型的输出。