Collaborative Research: Seasonality of circumpolar tundra - ocean and atmosphere controls and effects on energy and carbon budgets

合作研究：环极地苔原的季节性 - 海洋和大气控制以及对能源和碳预算的影响

• 批准号: 0902152
• 负责人: Howard Epstein
• 金额: $ 35.88万
• 依托单位: University of Virginia Main Campus
• 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: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0902152&HistoricalAwards=false
• 关键词: Collaborative; Research; Seasonality; circumpolar; tundra

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Changes in the magnitude and seasonality of Arctic summer vegetation production over the past several decades have been documented. These changes will likely accelerate and have consequences for the entire Arctic terrestrial system, in particular energy and element budgets, and will also feed back to marine and atmospheric systems. This project will characterize the seasonal linkages between the land surface greenness and a suite of land, atmosphere, and ocean characteristics, focusing on the Beringia/Beaufort Sea, where there have been strong positive increases in the Normalized Difference Vegetation Index (NDVI) over the past 25 years, and the west-central Arctic Eurasia region , where the NDVI trends have been slightly negative. The following questions will be addressed: (1) What are the spatial and temporal variabilities in the seasonality of various arctic system components (sea-ice concentration and thickness, ocean and land surface temperatures, ocean heat fluxes, snow cover, and vegetation as specified by the NDVI? Specifically, how do these vary zonally and meridionally in the circumpolar Arctic? (2) What role do the atmosphere and ocean circulation patterns play in controlling the seasonality of land temperatures and vegetation production? (3) How do changes in the seasonality of these arctic system components affect vegetation growth and carbon sequestration? Using both satellite and in situ data sets, this project will document the seasonal (daily to monthly timescales) of the tundra and marine climate systems at a regional scale throughout the Arctic. Reanalysis data sets will be employed to describe local circulation characteristics. A pan-arctic ice-ocean model will be used to describe ocean circulation patterns relevant for tundra vegetation, with the application of statistical analyses to investigate mechanisms of ocean-atmosphere-land relationships. A vegetation change model (ArcVeg) will analyze the consequences of land temperature changes for carbon production along climate, disturbance, and soil gradients. This model will be enhanced for seasonality studies, including transition to a daily time step, and will allow the examination of effects of seasonality changes on the carbon accumulated by different functional plant types and into different plant tissue types.

该奖项是根据2009年《美国复苏与再投资法》（公法111-5）资助的。过去几十年来，北极夏季植被生产的大小和季节性的变化已被记录。这些变化可能会加速，并对整个北极陆地系统（尤其是能源和元素预算）产生后果，也将使海洋和大气系统反馈。该项目将表征陆地绿色与一系列土地，气氛和海洋特征之间的季节性联系，重点关注Beringia/Beaufort Sea，在过去的25年中，标准化差异指数（NDVI）的正常化差异指数（NDVI）的正面增长幅度很大，西北地区的Eurasaasia eurasasia eurasasia eurasasia eurasasia eurasasia there ndvi趋势略有下降。将解决以下问题：（1）各种北极系统组件的季节性（海冰浓度和厚度，海洋和陆地表面温度，海洋热通量，雪覆盖，雪覆盖和植被）指定的NDVI指定的植被以及这些循环范围的循环范围（2）在循环范围内占据循环效应？控制土地温度和植被的季节性？泛亚冰山模型将用于描述与苔原植被相关的海洋循环模式，并应用了统计分析来研究海洋 - 大气 - 大圈关系的机制。植被变化模型（ARCVEG）将分析沿气候，干扰和土壤梯度的碳生产的后果。该模型将在季节性研究中增强，包括过渡到每日时间步骤，并将允许检查季节性变化对不同功能植物类型以及不同植物组织类型的碳的影响。