A 16-year record (2002–2017) of permafrost, active layer, and meteorological conditions at the Samoylov Island Arctic permafrost research site, Lena River Delta, northern Siberia: an opportunity to validate remote sensing data and land surface, snow, and permafrost models

Abstract

Abstract. Most of the world's permafrost is located in the Arctic, where its frozen organic carbon con-tent makes it a potentially important influence on the global climate system. The Arctic climate appears to be changing more rapidly than the lower latitudes, but observational data density in the region is low. Permafrost thaw and carbon release into the atmosphere is a positive feed-back mechanism that has the potential for climate warming. It is therefore particularly im-portant to understand the links between the energy balance, which can vary rapidly over hour-ly to annual time scales, and permafrost condition, which changes slowly on decadal to cen-tennial timescales. This requires long-term observational data such as that available from the Samoylov research site in northern Siberia, where meteorological parameters, energy balance, and subsurface observations have been recorded since 1998. This paper presents the temporal data set produced between 2002 and 2017, explaining the instrumentation, calibration, pro-cessing and data quality control. Additional data include a high-resolution digital terrain mod-el (DTM) obtained from terrestrial LiDAR laser scanning. Since the data provide observations of temporally variable parameters that influence energy fluxes between permafrost, active lay-er soils, and the atmosphere (such as snow depth and soil moisture content), they are suitable for calibrating and quantifying the dynamics of permafrost as a component in earth system models. The data also include soil properties beneath different microtopographic features (a polygon center, a rim, a slope, and a trough), yielding much-needed information on landscape heterogeneity for use in land surface modeling. For the record from 1998 to 2017, the average mean annual air temperature was − 12.3 °C, with mean monthly temperature of the warmest month (July) recorded as 9.5 °C and for the coldest month (February) − 32.7 °C. The average annual rainfall was 169 mm. The depth of zero annual amplitude niveau is at 20.8 m, and has warmed from − 9.1 °C in 2006 to − 7.7 °C in 2017. The presented data are available in the supplementary material of this paper and through the PANGAEA website (https://doi.org/10.1594/PANGAEA.891142).

A long-term (2002 to 2017) record of closed-path and open-path eddy covariance CO<sub>2</sub> net ecosystem exchange fluxes from the Siberian Arctic

“…The second largest unit consists of Late Pleistocene to Early Holocene sandy sediments with low ice content and covers 23 % of the northwestern part (Schneider et al, 2009). Samoylov Island is part of the third unit, the Mid-to Late Holocene river terrace (Bolshiyanov et al, 2015), which makes up about twothirds of the delta (Schwamborn et al, 2002).…”

Pathways of ice-wedge degradation in polygonal tundra under different hydrological conditions

“…Using a tiling approach to represent different parts of polygonal tundra allowed long-term (several decades) simulations on a landscape scale (several polygonal structures). We took advantage of a detailed in-situ data record from a site in the Lena River delta of Northern Siberia (Boike et al, 2018), which was used to provide model parameters and meteorological forcing data, as well as for comparisons between actual measurements and the simulation results. Our main objectives were:…”

Thaw processes in ice-rich permafrost landscapes represented with laterally coupled tiles in a Land Surface Model

“…All degradation stages described by Liljedahl et al (2016) can be found here, from non-degraded low-centered polygons to high-centered polygons with connected troughs (see Nitzbon et al, 2018). Between 1997 and 2017 the mean annual air temperature at the island was approximately -12.3 °C, with an annual liquid precipitation of 169 mm and mean end-of-winter snow depth of 0.3 m (Boike et al, 2018). The depth of zero annual amplitude is at 20.8 m, and has warmed from -9.1 °C in 2006 to -7.7 °C in 2017.…”

“…The island of Samoylov, located in the southern part of the delta, mainly consists of polygonal tundra surrounding a number of ponds and lakes (Fig. 1b;Boike et al, 2013Boike et al, , 2018). All degradation stages described by Liljedahl et al (2016) can be found here, from non-degraded low-centered polygons to high-centered polygons with connected troughs (see Nitzbon et al, 2018).…”

“…Numerous studies have been conducted on the island, including studies of water and surface energy balance (Boike et al, 2008, Langer et al, 2011a) and carbon cycling (Knoblauch et al, 2018;Knoblauch et al, 2015). As a well-studied site with available meteorological, soil physical, and hydrological measurements (Boike et al, 2018), it has also been used as test site for various permafrost modelling studies, including ESM validation and development (Chadburn et al, 2015;Chadburn et al, 2017;Ekici et al, 2014;Ekici et al, 2015).…”