A response of soils thermal regime to changing climate in McMurdo Dry Valleys, Antarctica: a modeling approach

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The summer climate of the McMurdo Dry Valleys typically hovers below the melting point and small changes to a surface energy balance can cause profound hydrological and ecological responses. Due to a lack of vegetation and low albedo, soils surface temperatures are particularly sensitive to climate and consequently can affect depth of the active layer – the zone of seasonal thaw and ecological habitat.  The spatial pattern of active layer depth is broadly known but its temporal variation is poorly understood. We present a simple model of hourly soil temperatures based on surface energy balance and subsurface conduction.  We are particularly interested in the two decades starting in the 1990’s when solar radiation was increasing (poster #137), air temperatures cooling, and the soil temperatures were warming. Initial results suggest surface temperatures increasing at a rate of 0.13°C per year since 1996. Warming of the soils can enhance melting of buried ice and as a consequence, destabilize local landscape.