Permafrost Thermal Dynamics and Cryostratigraphy at Villum Research Station, Station Nord, Eastern North Greenland (81°N)

Abstract

We provide the northernmost permafrost thermal analysis in Greenland through the ground temperature time series (2014–2021) and cryostratigraphy of two 20‐m deep boreholes (SN1 and SN2) at Villum Research Station, Station Nord (81°N). Three sedimentary units are identified in the stratigraphy: glacial, glaciomarine, and beach deposits. These sandy and gravelly deposits are interpreted to comprise a deglaciation and isostatic emergence sequence. Ice‐poor epigenetic permafrost grew downwards into the deposits following subaerial exposure. Relatively high salinity values (up to 70 ppt) are observed in the glaciomarine unit, resulting in freezing point depressions between 0 and −4°C. The Prinsesse Ingeborg Halvø study area has a polar tundra climate and is unique compared to other high Arctic areas because of a thick (>1 m), long‐lasting snow cover. This snow cover results in relatively high permafrost temperatures for the climate and latitude and the warmest known permafrost north of 80°N. Over the seven‐year study period, average 20 m permafrost temperature was −7.87°C at SN1 and −7.06°C at SN2. The warming rate at 20 m depth was 0.07°C/year at SN1 and 0.05°C/year at SN2, rates which are similar to those of other high Arctic sites. Active layer thickness, extrapolated from the temperature measurements, varied between 0.5 and 1.16 m. The interplay between snow dynamics and seasonal air temperature controls ground thermal regime in the study area. Air temperatures during autumn and midwinter, the fastest warming seasons, influence the ground thermal regime through the gradually developing, dense snowpack.

Permafrost and Active Layer Temperature and Freeze/Thaw Timing Reflect Climatic Trends at Bayelva, Svalbard

“…Air temperature warming has been observed at many Arctic sites, with Svalbard showing generally higher rates than the Arctic average (Isaksen et al., 2022b). However, other sites in the High Arctic showed similar rates, such as Station Nord in Greenland with 0.08°C/year, 1990–2020 (Strand et al., 2022). For Svalbard specifically, Isaksen et al.…”

“…On the other hand, this effect may also be site specific. A study of cold permafrost near Station Nord, Greenland, revealed permafrost warming rates of 0.07 and 0.05°C/year in two boreholes at 20 m depth for the recent period of 2014–2021 (Strand et al., 2022). Similarly, a study from the western Russian Arctic found increased permafrost warming in recent years (Vasiliev et al., 2020).…”

“…Air temperature warming has been observed at many Arctic sites, with Svalbard showing generally higher rates than the Arctic average (Isaksen et al, 2022b). However, other sites in the High Arctic showed similar rates, such as Station Nord in Greenland with 0.08°C/year, 1990-2020 (Strand et al, 2022). For Svalbard specifically, Isaksen et al (2022b) found that with 0.11°C/year Ny-Ålesund (2 km from Bayelva) had the weakest warming rate in two periods, 1991-2020 and 2001-2020, while eastern Svalbard in particular was warming more rapidly at more than 0.2°C/year.…”