Permafrost degradation risk zone assessment using simulation models

Abstract

Abstract. In this proof-of-concept study we focus on linking large scale climate and permafrost simulations to small scale engineering projects by bridging the gap between climate and permafrost sciences on the one hand and on the other technical recommendation for adaptation of planned infrastructures to climate change in a region generally underlain by permafrost. We present the current and future state of permafrost in Greenland as modelled numerically with the GIPL model driven by HIRHAM climate projections up to 2080. We develop a concept called Permafrost Thaw Potential (PTP), defined as the potential active layer increase due to climate warming and surface alterations. PTP is then used in a simple risk assessment procedure useful for engineering applications. The modelling shows that climate warming will result in continuing wide-spread permafrost warming and degradation in Greenland, in agreement with present observations. We provide examples of application of the risk zone assessment approach for the two towns of Sisimiut and Ilulissat, both classified with high PTP.

21st-century climate change around Kangerlussuaq, west Greenland: From the ice sheet to the shores of Davis Strait

“…This is particularly an issue around Kangerlussuaq and more generally in the Qeqqata municipality located in the discontinuous to continuous permafrost region of west Greenland (Christiansen and Humlum 2000). Here, the permafrost thaw potential has been classified as high (Daanen et al 2011), which is confirmed by the results presented in Christensen et al (2016). For these reasons, assessing the future climate of Greenland on both a regional and local scale is important both for infrastructure planning and future development as well as to more widely to identify processes and feedbacks that may affect ice-sheet mass loss.…”

A new approach to mapping permafrost and change incorporating uncertainties in ground conditions and climate projections

“…At such resolutions, it is difficult to consider detailed spatial variations in vegetation and ground conditions, and the results are not suitable for land use planning and engineering applications. Recently, several studies have modelled and mapped permafrost at finer spatial resolutions, ranging from 2 km to 10 m (Duchesne et al, 2008;Jafarov et al, 2012;Zhang et al, 2012Zhang et al, , 2013. In the North, however, the required maps for soil and ground conditions are coarse, with polygons in soil and surficial geology maps usually covering more than a hundred square kilometres.…”

Future permafrost conditions along environmental gradients in Zackenberg, Greenland

“…At a 10 m resolution, this study captured two important aspects which can be seen as part of the "thermal signature" of the permafrost landscape in Zackenberg: (a) the differences in maximum thaw depth between different ecosystem classes and (b) the spatial variability of ground temperatures to a large extent caused by spatially variable snow depths. Compared to large-scale (as in Daanen et al, 2011) or pointscale simulations (as in Hollesen et al, 2011), it provides a far more detailed (though still incomplete) assessment of the possible development of the Zackenberg permafrost landscape, which can be better linked to studies on the future ecosystem carbon turnover (e.g., Elberling et al, 2013). For modeling of large spatial domains, a grid cell size of 10 m is generally not feasible due to computation power.…”

“…The study aims to fill the gap between the coarse-and the point-scale modeling studies on the future ground thermal regime which are available for the Zackenberg valley so far. The 25 km scale, Greenlandwide assessment of Daanen et al (2011) puts Zackenberg in the zone of "high thaw potential" until the end century, with modeled ground temperatures of −5 to −2.5 • C and an active layer thickness of 0.5 to 0.75 m for the period 2065-2075. However, the detailed point-scale study by Hollesen et al (2011) suggests a future active layer thickness of 0.8 to 1.05 m for a site with average soil moisture conditions which are not representative of many other sites found in the Zackenberg valley, such as the wetlands.…”

“…Based on RCM output, projections of the future ground thermal regime have been performed for a number of permafrost regions, e.g., northeast Siberia (50 km resolution, Published by Copernicus Publications on behalf of the European Geosciences Union. Stendel et al, 2007), Greenland (25 km resolution, Daanen et al, 2011) and Alaska (2 km resolution, Jafarov et al, 2012). While this constitutes a major improvement, many processes governing the ground thermal regime vary strongly at even smaller spatial scales so that the connection between model results and ground observations is questionable.…”