Influence of Climate and Environmental Factors on the Thermal Regime of the Active Layer and Permafrost

气候和环境因素对活动层和多年冻土热状况的影响

• 批准号: 9531220
• 负责人: Thomas Osterkamp
• 金额: $ 21.25万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 1998-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9531220&HistoricalAwards=false
• 关键词: Influence; Climate; Environmental; Factors; Thermal

Permafrost is one of the primary components of the Arctic land-atmosphere-ice system. Recent unexpected discoveries of a large-amplitude temperature cycle in the permafrost and of large and systematic changes in active layer thicknesses (since 1986) indicate that the current understanding of climate-active layer-permafrost interactions needs improvement. These interactions are important because warmer air temperatures predicted in the Arctic from increases in greenhouse gases will cause permafrost to thaw as the active layer becomes thicker. A better understanding of the linkages between the atmosphere, soil surface, active layer, and permafrost is required to answer questions regarding the rate and extent of permafrost degradation, modifications to its thermal regime, release of carbon and trace gases by thawing permafrost, changes in soil moisture, the biota, the hydrological cycle, how these changes will influence the use of polar lands, and the development, calibration, and validation of small-scale numerical models (2 km grids) of land-atmosphere interactions that are to be nested in larger scale models. A permafrost research program is propose that combines field measurements, laboratory measurements, and analyses and interpretation of data to be obtained at six long-term study sites along a transect from Prudhoe Bay across the coastal plain and foothills into the Brooks Range. These sites are in undisturbed areas, span a wide range of permafrost, climatic, and environmental conditions, include drillholes in the permafrost (40 to 75 m in depth), and have a long time series of data (since 1983). This research will extend the time series of measurements at the sites and will focus on investigating how the active layer and continuous permafrost, in a variety of climatic and environmental setting, has responded and continues to respond to climate change. The primary thrust of the proposed research is to investigate the effects of climate (especially air temperatures, snow, wind and precipitation) and environmental factors (especially vegetation and surface morphology) and their interactions on the thermal and moisture regimes of the active layer and permafrost in an effort to answer questions raised by current research.

多年冻土是北极陆-气-冰系统的主要组成部分之一。 最近意外发现的大幅度的温度循环在冻土和大的和系统的变化，在活动层厚度（自1986年以来）表明，目前的气候活动层-冻土相互作用的理解需要改进。 这些相互作用很重要，因为随着活动层变厚，预计北极地区温室气体增加导致的气温升高将导致永久冻土融化。 更好地了解大气、土壤表面、活动层和永久冻土之间的联系，需要回答有关永久冻土退化的速度和程度、其热状况的改变、永久冻土融化释放的碳和微量气体、土壤水分的变化、生物区系、水文循环、这些变化将如何影响极地土地的使用以及开发、校准、以及验证将嵌套在较大尺度模型中的陆地-大气相互作用的小尺度数值模型（2公里网格）。 多年冻土研究计划的建议，结合现场测量，实验室测量，并分析和解释的数据将获得在六个长期的研究站点沿着一个横断面从普鲁德霍湾的沿海平原和山麓进入布鲁克斯范围。 这些地点位于未受干扰的地区，跨越各种永久冻土、气候和环境条件，包括永久冻土中的钻孔（深度为40至75米），并拥有长期数据序列（自1983年以来）。 这项研究将扩展现场测量的时间序列，并将重点调查活动层和连续多年冻土在各种气候和环境背景下如何应对气候变化。 拟议研究的主要目的是调查气候（特别是气温、雪、风和降水）和环境因素（特别是植被和地表形态）的影响，以及它们对活动层和永久冻土的热湿状况的相互作用，以回答当前研究提出的问题。