A Change of Seasonality of the Upper Arctic Ocean in Response to Atmospheric and Sea-ice Forcing

北冰洋上层季节性变化对大气和海冰强迫的响应

• 批准号: 0902090
• 负责人: Jiayan Yang
• 金额: $ 49.74万
• 依托单位: Woods Hole Oceanographic Institution
• 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=0902090&HistoricalAwards=false
• 关键词: Change; Seasonality; Upper; Arctic; Ocean

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The PI proposes to investigate the change of seasonality of the Arctic Ocean Ekman transport and upwelling/downwelling, and their relationships to key components of the Arctic System. A systematic investigation of the Arctic Ocean upwelling and its change of seasonality is needed in order to understand complex interactions among components of a rapidly changing Arctic System. Upwelling is arguably the single most important dynamical variable in oceanography. It forces oceanic gyres through the Sverdrup balance. Upwelling replenishes nutrients in the surface layer and helps to sustain phytoplankton production. It is a conduit for heat flux from the warm Atlantic Water layer of the Arctic Ocean to the mixed layer, where it influences the sea ice thermodynamics and the atmospheric circulation. Upwelling and Ekman transport affect the surface salinity and thus play roles in the oceanic thermohaline circulation. The most intense upwelling occurs along the Arctic coast, so a change of upwelling seasonality can influence land processes, such as the permafrost in nearshore sediments. Daily Ekman transport and upwelling from 1979 to 2006 have been estimated using satellite and buoy observations. This dataset will be updated, validated and made available to the community in the first year of this project. The PI will quantify the changes in seasonality of the Ekman layer, and examine how they are related to the decline in sea-ice cover and to oscillatory climate modes (such as the Arctic Oscillation). The impacts of the changes in seasonality of upwelling on the chlorophyll concentration, mixed-layer temperature and salinity will be examined.

该奖项由2009年《美国复苏和再投资法案》（Public Law 111-5）资助。PI提议调查北冰洋埃克曼输送和上升流/下降流的季节性变化，以及它们与北极系统关键组成部分的关系。 需要对北冰洋上升流及其季节性变化进行系统调查，以了解快速变化的北极系统各组成部分之间的复杂相互作用。 上升流可以说是海洋学中最重要的动力学变量。 它迫使海洋环流通过斯维尔德鲁普平衡。 上升流使表层的营养物质增加，有助于维持浮游植物的生产。 它是从北冰洋温暖的大西洋水层到混合层的热通量的管道，在那里它影响海冰热力学和大气环流。上升流和Ekman输运影响表层盐度，从而在大洋温盐环流中发挥作用。最强烈的上升流发生在沿着北极海岸，因此上升流季节性的变化可以影响陆地过程，例如近岸沉积物中的永久冻土。 利用卫星和浮标观测资料，对1979年至2006年的每日埃克曼输送和上升流进行了估算。 该数据集将在项目的第一年进行更新、验证并提供给社区。 PI将量化Ekman层的季节性变化，并研究它们如何与海冰覆盖率下降和振荡气候模式（如北极涛动）相关。将研究上升流季节性变化对叶绿素浓度、混合层温度和盐度的影响。