CALM III update June 5, 2012

This archive contains all Circumpolar Active Layer Monitoring (CALM) data submitted prior to June 5, 2012. The active-layer network of about 200 sites represents the only coordinated and standardized program of observations using standard measurement protocols designed to observe and detect decadal changes in the dynamics of seasonal thawing and freezing in high-latitude soils. The Intellectual Merit of this study lies in the need for long-term time series of active layer depth, ground temperature, and thaw settlement measurements at the same locations and across diverse terrain types and regions in order to identify scales of spatial variation, establish trends, and validate models.