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

非技术性这个项目将探索一个很少被研究的北极季节大气特征--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会发生什么变化。人们对AFZ的可变性或未来将如何变化知之甚少。这一特征被高层急流特征所覆盖，而AFZ最明显的地区是风暴发生频繁的地区，因此了解这一点对于了解和预测天气事件非常重要。在连接北极大气、海洋、陆地表面和水文循环方面，这项对AFZ的研究采用了系统的观点，培养下一代系统研究人员对于保持美国在环境科学方面的领先地位非常重要，因此该项目强烈地面向研究生的支持。这项研究的结果将被整合到大学课堂上，并将在国家冰雪数据中心-S月刊上亮相。为了向公众传达气候研究，为这项研究创建的数据集将被格式化，以用于球面上的科学技术。科罗拉多大学S·菲斯克天文馆的一名研究团队成员和研究生将在科罗拉多大学S·菲斯克天文馆的科学外展中向公众展示这些数据及其意义。技术上，这是一项努力，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研究夏季北极锋区的特征、可变性和对环境的影响，以及这种季节性特征在下个世纪可能会如何变化。大多数先前的研究得出结论，AFZ的发展主要是为了应对北冰洋和无雪陆地之间夏季供暖的差异。AFZ沿着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以北，那里的温度梯度似乎因北冰洋冷空气的地形陷阱而变得尖锐。地表的AFZ被对流层顶的急流状特征所覆盖。AFZ表现最好的地区是气旋生成频繁的地区，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制度也有重大影响，许多低气压在那里迁移和衰败。气旋向北冰洋中部的迁移也可能影响海冰状况。这项研究将集中于：AFZ的季节发展如何与陆地上无雪条件的季节时间、海冰边缘的位置、表面温度和地形的变化有关；是否支持对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的变异性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世纪改变以应对季节性积雪、海冰条件和大气环流模式的潜在变化。这项研究将使用来自三个大气再分析的数据，即卫星被动微波记录的海冰范围、雷诺海面温度、卫星得出的地面积雪范围、天气研究和预报区域模式的试验以及耦合全球模式的输出。

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.