The circumpolar active layer monitoring (calm) program: Research designs and initial results¹

Soil temperature response to 21st century global warming: the role of and some implications for peat carbon in thawing permafrost soils in North America

“…The maximum depth that can be measured is therefore limited by the length of the steel rod (∼1.20 m). As the period of observations in the CALM database varies for each station, we averaged annual values for the most recent 10 years and compared those values with the mean modeled annual ALT for the period 2001-2010. ALT at a particular location depends on a number of factors including thermal properties of soil, vegetation, snow cover, soil moisture, and there is consequently a wide range of ALT observations across a spectrum of temporal and spatial scales (Brown et al, 2000) and within a single site (Hinkel and Nelson, 2003). For example, Wright et al (2009) found the variability of the ALT in peatlands in northwestern Canada over distances of less than one meter to be correlated with lateral water flow converging to frost table depressions, a process that is not taken into account in our modeling approach.…”

“…To further evaluate the model and the assumptions regarding the properties of mineral and peat soils we compared modeled active layer thickness (ALT) under contemporary (2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010) conditions with ALT measurements from 56 sites in Alaska and Canada, representing a wide range of soil, topographical, and climatic conditions, from the Circumpolar Active Layer Monitoring (CALM; Brown et al, 2000) program. The annual ALT measurements generally represent an average value from a sample grid of 121 points over an area of 1 ha or 1 km 2 .…”

Study of the active layer at the Spanish Antarctic station “Gabriel de Castilla”, Deception Island, Antarctica

“…Este estudio comprende distintas aproximaciones metodológicas tomadas del clásico estudio de los suelos congelados, tal y como se realiza dentro de los protocolos internacionales del estudio térmico de los suelos en ambientes glaciares y periglaciares (Thermal State of Permafrost -TSP) y de la monitorización de la capa activa (Circumpolar Active Layer Monitoring -CALM) (ej., Brown et al, 2000;Matsuoka y Humlum, 2003;Nelson et al, 2004;Matsuoka, 2006), dentro de la red de estudio de la temperatura del suelo permanentemente congelado (Ground Temperature Network Permafrost -GNT-P) englobado en la Asociación International del Permafrost (International Permafrost Association -IPA).…”

“…Esta profundidad se midió mediante sondeos mecánicos manuales consistentes en la introducción de una barra de acero de 1 cm de diá-metro y 1 m de longitud en el terreno hasta alcanzar el terreno congelado (Figura 4), siguiendo los mencionados protocolos internacionales (Brown et al, 2000;Matsuoka y Humlum, 2003;Nelson et al, 2004;Matsuoka, 2006), cuyo error es inferior a 1 cm. Estas mediciones fueron realizadas en el entorno del módulo de vida de la BGdC a distancias crecientes desde el exterior de la misma, así como en los alrededores más próximos.…”

Permafrost and active layer monitoring in the maritime Antarctic: Preliminary results from CALM sites on Livingston and Deception Islands

“…The Circumpolar Active Layer Monitoring (CALM) program is a network of permafrost observatories distributed over both Polar Regions and selected midlatitude mountain ranges (Brown et al, 2000). CALM is an international global-change monitoring program concerned with active-layer dynamics and the shallow permafrost environment.…”