Adam Nawrot

Ice volume changes (1936-1990-2007) and ground-penetrating radar studies of Ariebreen, Hornsund, Spitsbergen

Ariebreen is a small (0.37 km2)-valley glacier located in southern Spitsbergen. Our ground-penetrating radar surveys of the glacier show that it is less than 30 m thick on average, with a maximum thickness of 82 m, and it appears to be entirely cold. By analysing digital terrain models of the ice surface from different dates, we determine the area and volume changes during two periods, 1936–1990 and 1990–2007. The total ice volume of the glacier has decreased by 73% during the entire period 1936–2007, which is equivalent to a mean mass balance rate of −0.61±0.17 m y−1 w.eq. The glacier thinning rate has increased markedly between the first and second periods, from −0.50±0.22 to −0.95±0.17 m y−1 w.eq. To access the supplementary material for this article, please see Supplementary Files under Article Tools online.

Run-off modelling in an Arctic unglaciated catchment (Fuglebekken, Spitsbergen)

ABSTRACT The goal of this study is to test applicability of the conceptual catchment run-off HBV model to simulate discharge in small non-glaciated Arctic catchment. Within two ablation seasons, 2014 and 2015, in the Fuglebekken catchment (Spitsbergen, Svalbard), selected hydro-meteorological measurements were conducted, including discharge measurements in 10 min interval by Nivus PCM-F device with active Doppler sensor. The model parameters were calibrated on discharge measurements from both years separately and verified independently. As the transformation from rainfall to runoff includes a number of processes with different dynamics and timescales, the proper description of the processes and their simulation of discharge depend on the temporal resolution of the data. For that purpose, the relationships between the calibration and validation results, and optimal model parameters with different time steps were analyzed. It was found that calculated fit of simulated to observed discharge, depends on the year, time step and data averaging. The best results were obtained for the model from year 2015 for 3 and 6 h using averaged input data.

Spatial variations in air temperature and humidity over Hornsund fjord (Spitsbergen) from 1 July 2014 to 30 June 2015

ABSTRACT This article presents the variations in air temperature and humidity in the region of the Hornsund fjord for the period from 1 July 2014 to 30 June 2015. Based on measurements at 11 sites, it was established that significant topoclimatic differences were dependent on height above sea level, substrate type, distance from the sea, exposition, atmospheric circulation and the ice conditions. The thermal and humidity conditions of individual sites are presented in relation to the weather conditions at the Polish Polar Station in Hornsund (HOR). In the study period, the warmest annual mean air temperature occurred at Hyttevika (HYT), and the coldest on the summit of Fugleberget (FUG), respectively, +1.1°C and −3.7°C relative to HOR. Meanwhile, relative humidity differs from HOR values most strongly on Fugleberget, where it is greater by an average of 14%. Atmospheric circulation and ice cover were shown to have a significant impact on thermal and humidity conditions. The greatest spatial variations in air temperature (3.0°C) in Hornsund region (between HOR and FUG) occurred in winter during anticyclonic advection from the northern sector. The greatest difference in relative air humidity (20%) relative to HOR occurred in FUG in autumn during cyclonic advection from the eastern sector. The east–west thermal and humidity gradients along the fjord are more pronounced when sea ice is present. Differences in air temperature and relative humidity between the sites located in the inner (TRE) and outer parts of the fjord (HG4 and HYT) rose by about 2.0–2.5°C and 7–9%, respectively.