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.

The monitoring of the mass balance of the Werenskioldbreen (Wedel Jarlsberg Land, Spitsbergen, Svalbard) in the years 1999-2002 and 2009-2018. It is calculated on the base of 4 to 9 ablation stakes (depend on year). The mass balance is determined by conducting field surveys on floating calendar dates (floating-date system). Data have also been submitted to the World Glacier Monitoring Sevice (WGMS, https://wgms.ch)

1. Two high-quality UAV movies taken in Hornsund fiord on 15th Sep 2016 with Phantom 3 Advanced usage. The movies are focused on Horyzont II ship during unloading goods to the Polish Polar Station Hornsund. Format file: .MOV. 2. Dataset consist six UAV movies taken in neighborhood of stake no. 4 of Hansbreen, one taken in the vicinty of stake no. 6 of Hansbreen and two on Tuvbreen. The movies from stake no. 4 show the ablation zone, crevasses, glaciers in the area and a team of University of Silesia scientists during maintanance of automatic weather station (AWS). The movie from stake no. 6 presents the surface of Hansbreen towards accumulation zone. The movies from Tuvbreen show the area around, surface of the glacier and University of Silesia team. UAV: Phantom 3 Advanced. Format file: .MOV. 3. One high-quality UAV movie taken from West morain of Paierbreen 22nd Aug 2016 with Phantom 3 Advanced usage. The movie is focused on the front of Paierlbreen. Format file: .MOV. 4. Two high-quality UAV movies taken on Silesiabreen 23nd Aug 2016 with Phantom 3 Advanced usage. The movie is focused on the snowline of Silesiabreen, University of Silesia scietists while fieldwork and neighbourhood. 5. UAV movie of Storbreen upper ablation area in 21st Aug 2016. 6. Three high-quality UAV movies taken from vicinity of Treskelen in Hornsund on 12 Sep 2016 with Phantom 3 Advanced usage. The movies are focused on the University of Silesia team during automatic weather station maintanance, sailing boat operated by scientists and Hornsund fiord. 7. A high-quality UAV movie taken from vicinity of Brateggbreen on 5 Sep 2016 with Phantom 3 Advanced usage. The movie is focused on Brateggbreen front and its proglacial lake. Format file: .MOV. 8. UAV movies of Werenskoildbreen front and morain in summer 2016

Subglacial topography was derived from radio-echo sounding (RES) survey conducted in spring 2008 by the University of Silesia research team (M. Grabiec and J. Jania) in cooperation with the Institute of Geophysics Polish Academy of Sciences (D. Puczko) and the Maria Curie-Sklodowska University (G.Gajek). The profiles were acquired by the radar system equipped with 25 MHz unshielded antenna pulled behind snowmobile. Traces were recorded every 0.5 s, that translates into 1.5-2.0 trace-to-trace distance depending on the vehicle’s velocity. Traces were positioned by GNSS receiver working in differential mode with 3D accuracy ± 1m. In total over 100 km of RES profiles were acquired on Hansbreen, 66 km on Werenskioldbreen and 43 km on Renardbreen. RES data were processed using standard procedure including: DC-offset, time-zero adjustment, 2-D filter, amplitude correction, bandpass filtering and migration. Time-to-depth conversion applied average radio-wave velocity in glacier ice 16.4 cm ns-1 calculated based on CMP analysis performed on Hansbreen in the same season as the GPR profiling. The ice/bed interface was picked up semi-automatically with RMSE 5.3 ns (0.43 m) (Grabiec, 2017). Then the bedrock elevation data were interpolated over studied glaciers taking into account elevation of nonglaciated surroundings (Grabiec 2017) and bathymetry at the front of tidewater Hansbreen (Grabiec et al. 2012). Finally produced 100 m resolution DEMs are in UTM 33X WGS84 reference system. DEM of 300 m resolution is freely available. For 100 m resolution DEM please contact: mariusz.grabiec@us.edu.pl. The data were collected and processed under following projects: • IPY/269/2006 GLACIODYN The dynamic response of Arctic glaciers to global warming • UE FP7-ENV-2008-1 ice2sea Estimating the future contribution of continental ice to sea-level rise • PNRF-22-AI-1/07 AWAKE Arctic Climate and Environment of the Nordic Seas and the Svalbard – Greenland Area • 03/KNOW2/2014 KNOW Leading National Research Centre Reference: Grabiec M., Jania J., Puczko D., Kolondra L., and Budzik T., 2012: Surface and bed morphology of Hansbreen, a tidewater glacier in Spitsbergen. Polish Polar Research 38(2): 111-138. Grabiec M. 2017: Stan i współczesne zmiany systemów lodowcowych południowego Spitsbergenu w świetle badań metodami radarowymi. Wydawnictwo Uniwersytetu Śląskiego, 328 s. Decaux, L., Grabiec, M., Ignatiuk, D., and Jania, J. 2018: Role of discrete recharge from the supraglacial drainage system for modelling of subglacial conduits pattern of Svalbard polythermal glaciers, The Cryosphere Discuss., https://doi.org/10.5194/tc-2017-219, in review.

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).

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).

Glaciers facies (ice, superimposed ice, firn) extents of Hansbreen, Storbreen and Flatbreen delivered from unsupervised classifications of single, dual and fully-polarimetric SAR data (ALOS-2 PALSAR, RADARSAT-2, Sentinel-1, ERS-2 SAR) between 2008 and 2018. Methods of classification: unsupervised ISO classification, H-a Wishart Classification. Results validated with terrestrial measurements (shallow ice cores drilling, Ground Penetrating Radar measurements). Research supported by the European Space Agency, Third Party Missions grant and Svalbard Science Forum, Arctic Field Grant 2018. For more details, please e-mail to bbarzycka@us.edu.pl.

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.

The base contain: 1. List (*xls) of terrophotogrammetric photographs taken by Poles na Spitsbergen from 1934 till 2016: 2. Skaning above photographs with resolution of 2400 dpi, file format *.tif and *.jpg (400 dpi). All photographs were taken by means of instrument type Phototheodolite Zeiss 19/1318 on glass plates. Authors of photographs: Antoni Rogala-Zawadzki, Cezary Lipert, Stanisław Rudowski, Leszek Kolondra, Jacek Jania, Jerzy Wach, Krzysztof Migała, Janusz Karkoszka, Małgorzata Błaszczyk and other unknown members of Polish Expeditions organized by Institute of Geophysic Polish Academy of Science in Station HORNSUND. Fot better identification of all photographs was prepared presentations (in *.pptx and *.pdf formats), where photographs there are arranged in classic form used for terrophotogrammetric stereoscopic photographs: A, AL, AR, B, BL, BR (the meaning of a letter: A - right photogrammetric station and photograph taken in normal case [90°]; B - left photogrammetric station and photograph taken in normal case [90°]; AL - photograph taken from right station in left direction; AR - photograph taken from right station in right direction; BL - photograph taken from left station in left direction; BR - photograph taken from left station in right direction). Other photographs (e.g. panoramic) has additional informations. Boths kind of presentation are prepared in chronological and tematical (for objects) order.

1. Dataset of UAV vertical aerial photos of Calypsobyen obtained from height of: 100m (58 photos), 60m (45 photos) and 30m (59 photos). Used UAV: Phantom 3 Advanced, date of acqusition: 16 Aug 2016. 2. Dataset of UAV vertical aerial photos of Paierlbreen east morain/dead ice obtained from height of 50m (152 photos). Area covered: ~250x~130m (with gaps).Used UAV: Phantom 3 Advanced, date of acqusition: 22 Aug 2016. 3. Dataset of UAV vertical aerial photos of Storbreen, close to Komsa (52 photos). Area covered: ~350x~230m. Used UAV: Phantom 3 Advanced, date of acqusition: 21 Aug 2016. 4. Dataset of UAV vertical aerial photos of Werenskoildbreen's south moraine (300 photos). Area covered: ~200x~350m and ~250x~250m. Used UAV: Phantom 3 Advanced, date of acqusition: 7 Sep 2016.