Snow depth data series contain records obtained by high frequency GPR on selected glaciers of Hornsund area (S Svalbard) since 2008. Currently the largest collection regards Hansbreen. Data for other glaciers are successively appended. The GPR survey on Hansbreen is regularly carried out approximately along the same tracks. Due to dynamically changing glacier surface topography influencing different survey abilities the some parts of profiles are modified in consecutive seasons. The total distance of Hansbreen profiles are as follows (Fig.1): 63.9 km (2008), 117,5 km (2011), 105,1 km (2013), 103,9 km (2014), 98,5 km (2015), 91,1 km (2016), 101,0 km (2017) and 108,4 km (2018).

In the years 2009-2019, 49 samplings (shallow drilling or snowpits) were made on the glacier during the spring measurement campaigns in order to determine the bulk snow density and SWE. The average density of snow cover ranges from 386 to 447 kg/m3. The dataset includes part of the results from the project “Hindcasting and projections of hydro-climatic conditions of Southern 350 Spitsbergen” (grant no. 2017/27/B/ST10/01269) financed by the Polish National Science Centre, “Arctic climate system study of ocean, sea ice, and glaciers interactions in Svalbard area”—AWAKE2 (Pol-Nor/198675/ 17/2013), supported by the National Centre for Research and Development within the Polish–Norwegian Research Cooperation Programme and the SvalGlac—Sensitivity of Svalbard glaciers to climate change, the ESF Project, the project Integrated Arctic 355 Observing System (INTAROS)- Horizon 2020, the ice2sea 7th FP projects. The studies were carried out as part of the scientific activity of the Centre for Polar Studies (University of Silesia in Katowice) with the use of research and logistic equipment of the Polar Laboratory of the University of Silesia in Katowice.

Results of supervised classification of six Landsat 8 images acquired on: 25 May, 3 June, 22 June, 15 July, 4 August and 20 August 2014, covering glaciers in Hornsund fiord. Method of classification: Maximum Likelihood. The results show variability of snow cover areas in melting period of 2014 for glaciers located in Hornsund fiord and larger than 9 km2 (Körberbreen, Samarinbreen, Chomjakovbreen, Mendelejevbreen, Svalisbreen, Hornbreen, Storbreen, Kvalfangarbreen, Mühlbacherbreen, Paierlbreen and Hansbreen). For more information, please check: https://doi.org/10.3390/w9100804 Overview: Results of Maximum Likelihood classification of Landsat 8 images for analysed glaciers. Red - snow cover, yellow - glacier ice, black - debirs, grey - cloud cover.

Glaciers facies extents of Vestfonna delivered from unsupervised classifications of SAR data (fully-polarimetric ALOS PALSAR, single polarimetric ERS-2 SAR) for 2009 year. Date of SAR images acquisitions: 4, 7, 20, 23, 26 May 2009 (VV Single Look Complex ERS-2 SAR), 22 May 2009 (ALOS PALSAR Single Look Complex 1.1, quad polarimetry). Method of classification: K-means classification, H-a Wishart Classification. Results validated with Ground Penetrating Radar data. For more information, please check: https://doi.org/10.1016/j.rse.2018.11.020 Overwiew of results of different classification methods with comparison to GPR data. Top panel: Pauli decomposition, middle panel: H-a Wishart classification, bottom panel: k-means classification. For more information, please check: https://doi.org/10.1016/j.rse.2018.11.020 (Figure 7).

Glaciers facies extents of Langjökull delivered from unsupervised classifications of fully-polarimetric SAR data (ALOS-2 PALSAR, RADARSAT-2) for 2018 year. Date of SAR images acquisitions: 12, 16 Mar 2018 (Fine Quad Pol RADARSAT-2), 17 Mar 2018 (High Sensitive Quad Pol ALOS-2 PALSAR). Method of classification: H-a Wishart Classification. Results validated with terrestrial measurements (shallow ice cores drilling, Ground Penetrating Radar measurements). Research done with cooperation with University of Iceland and supported by the European Space Agency, Third Party Miassions. Overwiew of results of RADATSAT-2 (16 Mar 2018; Fine Quad Pol) classification of south part of Langjökull. Black line - contour of Langjökull; other colours - different scattering properties of SAR microwaves. For more details please contact Barbara Barzycka (bbarzycka@us.edu.pl).

• Discharge measurements were conducted from May/June/July to September/October in the years 2007–2012. Direct observation periods were 62, 51, 61, 40, 121, and 35 days in the consecutive years. The data set was obtained from CTD-DIVER DI 261 or Mini-Diver (Van Essen Instruments, Delft, The Netherlands) logger with barometric compensation by BaroDiver (Schlumberger, Houston, TX, USA) with 10-min intervals and flow velocities were measured with a SEBA F1 current meter (SEBA Hydrometrie GmbH, Kaufbeuren, Germany). Mean daily discharge and total runoff in the hydrologically active season was calculated on the basis of the 24h running average of the water level and a rating curve (Appendix 1). More details have been reported by Majchrowska E., Ignatiuk D., Jania J., Marszałek H., Wąsik M., 2015: Seasonal and interannual variability in runoff from the Werenskioldbreen catchment, Spitsbergen. Polish Polar Research vol. 36, no. 3, pp. 197–224. doi: 10.1515/popore−2015−0014 • Hydrological data for Werenskioldbreen - archive of the University of Silesia. The base contain mean daily discharge in the years: 1972, 1973, 1974, 1979, 1980, 1983, 1985, 1986, 1988, 1998, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2017 (18 hydrologically active seasons) – Appendix 2

https://egusphere.copernicus.org/preprints/2023/egusphere-2023-115/

The positions of the glacier termini in Hornsund are derived with very high frequency in the period 1991–2018. Over 230 multispectral and Synthetic Aperture Radar (SAR) data were used: LANDSAT 5, LANDSAT 7, LANDSAT 8, Terra ASTER, Alos AVNIR, SPOT 5, ERS-1, ERS-2, ENVISAT, Alos PALSAR, TerraSAR-X, TanDEM-X, and Sentinel-1. SAR data were used to detect any variability in the glacier front during the polar night. The satellite data were digitized manually to obtain the ice cliff position. Multispectral images were orthorectified and geocoded in PCI Geomatica and ArcGIS software. SAR data were usually provided at the SLC level, so that both radiometric and geometric corrections could be applied using the same methods, and with the same digital elevation model (2008 DEM SPOT developed by the IPY-SPIRIT Project; Korona et al., 2009). The SAR data were processed in BEAM (http://www.brockmann-consult.de/cms/web/beam). Sentinel data downloaded from the Sentinel’s Data Hub were already processed. Data not published.

Englacial water pressure was recorded by placing HOBO 250-Foot Depth Water Level Data Loggers in the center of Crystal Cave (N77°02' E15°34', 174 m) channel system (Hansbreen glacier). Data loggers were set to record values every 30 minutes, resampled to daily in post-processing, and have a resolution of 2.55 kPa for a typical error of 3.8 cm water level. Water pressure was converted in water level. Sensor was placed in the cave by drilling anchor points into the ice above a vertical shaft, then hanging cables down in the center of conduit. Stabilization cables were used to keep sensors from attaching to and freezing into ice walls by manually rappelling down to the sensor and attaching it to three horizontal cables, anchored into the ice walls at about 120 degrees apart. Senor was installed in Crystal Cave at about 100 m total distance from the cave entrance, in ice about 74 m thick. The sensor was installed 28 m above the glacier bed and 46 m below the ice surface.

The ortophotomap of Hornsund Fiord with changes to the front positions of tidewater glaciers. The front positions are based on different cartographical maps and satellite data. The base map is Sentinel 2 satellite image acquired on 6 July 2018. Citation: Kolondra L., 2018. Hornsund Fiord - Changes to the front positions of tidewater glaciers. University of Silesia, Faculty of Earth Sciences.