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

Abstract

Using regional climate-model runs with a horizontal resolution of 5.5 km for two future scenarios and two time slices (representative concentration pathway [RCP] 4.5 and 8.5; 2031-2050 and 2081-2100 relative to a historical period (1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010), we study the climate change for the Qeqqata municipality in general and for Kangerlussuaq in particular. The climate-model runs are validated against observations of temperature and surface mass balance and a reanalysis simulation with the same model setup as the scenario runs, providing high confidence in the results. Clear increases in temperature and precipitation for the end of the 21st century are shown, both on and off the ice sheet, with an off-ice sheet mean annual temperature increase of 2.5-3°C for the RCP4.5 scenario and 4.8-6.0°C for the RCP8.5 scenario, and for precipitation an increase of 20-30% for the RCP4.5 scenario and 30-80% for the RCP8.5 scenario. Climate analogs for Kangerlussuaq for temperature and precipitation are provided, indicating that end-of-the-century Kangerlussuaq mean annual temperature is comparable with temperatures for the south of Greenland today. The extent of glacial retreat is also estimated for the Qeqqata municipality, suggesting that most of the ice caps south of the Kangerlussuaq fjord will be gone before the end of this century. Furthermore, the high-resolution runs are compared with an ensemble of six models run at a 50 km resolution, showing the need for high-resolution model simulations over Greenland. ARTICLE HISTORY

Ice wedge polygon stability on steep slopes in West Greenland related to temperature and moisture dynamics of the active layer

“…Moreover, it is as yet unknown how climate change will influence these complex systems. Annual mean temperature in West Greenland is expected to increase by 2.5–3°C for the RCP4.5 scenario and by 4.8–6.0°C for the RCP8.5 scenario, as well as an increase in precipitation of 20–30 and 30–80%, respectively, by the end of this century 74 . This may change the moisture regime toward longer periods of positive pore pressure, destabilization of ice wedge polygons, and mass movement and solifluction along north‐facing slopes.…”

Robustness of high-resolution regional climate projections for Greenland: a method for uncertainty distillation

“…The model configuration we want to test in this study is the RCM HIRHAM5 (Christensen et al 2006) set up with a 5.5 km spatial resolution for a domain covering Greenland and Iceland (Lucas-Picher et al 2012, Langen et al 2015, Boberg et al 2017, domain 3 in Fig. 1.…”

Environmental change and impacts in the Kangerlussuaq area, West Greenland

“…Two articles by Levy et al (2018) and Carrivick et al (2018) now provide new insights into the dynamics of the ice-sheet margin during the Holocene based on 10 Be dating of boulders and bedrock and 14 C dating of roots and leaves in sediment profiles from drained ice-marginal lakes. Future climate change simulations are presented by Boberg et al (2018), who used the climate scenarios to suggest that by the end of the twenty-first century the mean annual air temperature in the Kangerlussuaq area will be similar to the temperature in south Greenland today, and that the huge, local ice caps south of the fjord will almost disappear entirely by the end of the twentyfirst century.…”