Seasonal soil active layer measurements from a Circumpolar Active Layer Monitoring (CALM) grid, (U9B) 'Happy Valley 1km Grid', Alaska.

This site is registered with the Circumpolar Active Layer Monitoring (CALM) program. It is one among a network of sites that represent a coordinated effort to standardize the collection and access to thaw measurements in representative undisturbed permafrost landscapes. This dataset contains long-term spatial thaw depth observations using mechanical probing on dates indicated by file column headers. To ensure relative consistency within the record, end-of-season measurement dates are within the same Julian calendar week during the height of the thaw season (mid-August to mid-September). It is important to note that the date of maximum annual thaw, interpreted as the active layer thickness, can vary from year to year and between sites.本站点已注册加入环北极活动层监测（Circumpolar Active Layer Monitoring, CALM）计划。该站点是全球协同监测网络的组成成员之一，该网络旨在通过统一协调的工作，实现对典型未受干扰永久冻土景观中解冻观测数据的采集与共享的标准化。本数据集包含通过机械探杆测量获取的长期空间解冻深度观测数据，观测日期由文件列标题标注。为保障数据集记录的相对一致性，季末测量日期均安排在解冻旺季（8月中旬至9月中旬）的同一儒略历周内。需要说明的是，被定义为活动层厚度的年度最大解冻日期，会随年份以及站点的不同而发生变化。