Seasons of Change in the Arctic Environment

北极环境的季节变化

• 批准号: 0901962
• 负责人: Mark Serreze
• 金额: $ 86.3万
• 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: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2013-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0901962&HistoricalAwards=false
• 关键词: Seasons; Change; Arctic; Environment

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The Arctic system is strongly defined by its seasonality. The extreme annual cycle of solar radiation, interactions between the Arctic and lower latitudes, within-Arctic interactions between the land, ocean, and atmosphere, and the energetics of freeze and thaw, combine to lend a complexity and richness to Arctic seasonality not seen elsewhere on the planet. This seasonality is changing. Summer sea ice extent is declining, attended by strong autumn rises in air temperature over the Arctic Ocean. Active layer freeze-up in Siberia is occurring later in the winter. These and other emerging changes will become more prominent in coming decades, with impacts promising to cascade through the physical, chemical, biological, and socio-economic components of the system.This research will identify the dominant climate forcings, feedbacks, and component linkages driving change in Arctic system seasonality, and they will shape the evolution of the system through the 21st century. This will require consideration of changes in global radiative forcing, energy and mass transports from lower latitudes into the Arctic, and between the land, ocean, and atmosphere within the Arctic, and how these influence the Arctic?s physical, chemical, and biological processes. A framework of passive versus active controls will help to organize the investigations. A passive control is the control by background warming. An example is how Arctic warming will lead to shorter seasonal duration of snow cover. An active control refers to altered seasonality driven by changes in energy or mass transports into the Arctic from lower latitudes or within the Arctic itself. An example is how reduced autumn sea-ice extent leads to warming over the ocean, which then, through regional atmospheric transport, may lead to warming over adjacent land. Changes in seasonality will likely often reflect both passive and active controls. Diagnostics such as seasonal anomaly structures, defined as the seasonal cycle of a state variable for a given year or years relative to the long-term climatology, will be used to evaluate how seasonality in different system elements has evolved through the instrumental record. These observational analyses will guide modeling experiments to examine the sensitivity of state variables to active and passive controls and how changing seasonality will shape the future of the system.

该奖项是根据2009年的《美国复苏和再投资法》（公法111-5）资助的。北极系统由其季节性强烈定义。太阳辐射的极端年度周期，北极和较低纬度之间的相互作用，陆地，海洋和大气之间的北极相互作用以及冻结和融化的能量，使其对北极季节的复杂性和丰富性相结合，无法在星球上其他地方看到。这种季节性正在改变。夏季海冰范围正在下降，这是由于北极海上的空气温度强劲的秋季升高。西伯利亚的主动层冻结发生在冬季晚些时候。 These and other emerging changes will become more prominent in coming decades, with impacts promising to cascade through the physical, chemical, biological, and socio-economic components of the system.This research will identify the dominant climate forcings, feedbacks, and component linkages driving change in Arctic system seasonality, and they will shape the evolution of the system through the 21st century. 这将需要考虑全球辐射强迫，能量和质量从北极下部以及北极内的陆地，海洋和大气之间的变化，以及这些如何影响北极的物理，化学和生物学过程。被动控制与主动控制的框架将有助于组织调查。被动控制是背景变暖的控制。一个例子是北极变暖将导致季节性降雪持续时间较短。主动控制是指能量变化或从下纬度或北极本身内部到北极的变化驱动的季节性改变。一个例子是减少秋季冰的范围如何导致海洋上的变暖，然后，通过区域大气运输，这可能会导致邻近土地上的变暖。季节性的变化可能通常反映出被动和主动控制。相对于长期气候，将诸如季节性异常结构（季节性异常结构）定义为状态变量的季节性周期，将用于评估不同系统元素中季节性在仪器记录中如何演变的季节性。这些观察性分析将指导建模实验，以检查状态变量对主动和被动控制的敏感性，以及改变季节性将如何影响系统的未来。