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.

该项目将探讨一个很少研究的北极季节性大气特征的特征，变化和环境影响，称为夏季北极锋区（AFZ），以及它在下一个世纪可能如何变化。对AFZ的可变性或未来将如何变化知之甚少。该特征被一个类似高空急流的特征所覆盖，AFZ最明显的地区是风暴频繁发生的地区，因此了解它对理解和预测天气事件很重要。在连接北极大气，海洋，陆地表面和水文循环，这项研究的AFZ采用了系统的观点，并浸泡在系统研究的下一代研究人员是保持美国的重要。这项研究的结果将被纳入大学课程，结果将在国家冰雪数据中心展出。每月亮点为了向公众宣传气候研究，为这项研究创建的数据集将被格式化为Science on a Sphere技术。一名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，作为科罗拉多大学科学推广活动的一部分。这是一项努力，以利用一套先进的大气再分析，卫星遥感和模型实验的数据，以解决夏季北极锋区（AFZ）的特点，变化和环境影响，以及如何这个季节性特征可能会改变在下一个世纪。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的夏季加热对比。沿着欧亚和阿拉斯加海岸的AFZ最发达，特别是在东西伯利亚和阿拉斯加的布鲁克斯山脉北部，那里的温度梯度似乎是由于北冰洋冷空气的地形捕获而加剧的。在对流层顶的喷流状特征覆盖在地面的AFZ上。最能表达AFZ的地区是气旋生成频繁的地区，这些气旋不仅对沿着北极海岸的夏季降水状况有重大影响，而且对北冰洋中部也有重大影响，北冰洋中部是许多低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。这项研究将侧重于：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;是否支持AFZ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;如何用气旋生成和夏季降水的模式来表达AFZ的变率;以及AFZ在世纪将如何应对季节性积雪的变化，海冰状况和大气环流模式的潜在变化。这项研究将利用来自三个大气再分析的数据、来自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覆盖范围、天气研究和预报区域模型的试验以及全球耦合模型的输出。