This dataset comprises measurements from moored Acustic Doppler Current Profiler (ADCP), collected by the S1 Mooring, which is managed by the Institute of Polar Sciences of the National Research Council (CNR) and National Institute of Oceanography and Applied Geophysics (OGS). The data was gathered on the Fram Strait south of the Spitsbergen in an open-sea area strongly influenced by both the interaction between Atlantic (northward-moving) and Arctic (southward-moving) waters as well as by the presence and winter formation of sea ice and atmospheric forcing. The easternmost part of the Fram Strait, relatively warm and salty Atlantic waters flow, bringing heat to the Arctic region and contributing to the Atlantification phenomenon. The processes responsible of the inter-annual and seasonal variability of the deep current flow in this open sea region are still unknown and also what the implications are related to ongoing climate change and in particular to the progressive decrease of sea ice cover in the winter period. To understand these dynamics, a deep-water oceanographic S1 Mooring was anchored at about 1040 meters depth, since June 2014. The dataset is also part of the SIOS-Svalbard Integrated Arctic Earth Observing System, developed to observe the impacts of climate change, including the rapid loss of sea ice cover, the retreat of local glaciers, and the Atlantification of Arctic seas. The ADCP mounted at 420 m measure: sea-water currents intensity and direction along the water column. The acquisition of this time series data is still ongoing and will continue, bolstered by the inclusion of this infrastructure within the framework of the Italian PNRR project ITINERIS. This ensures sustained data collection and further enhances our understanding of the observed environmental changes.

This dataset comprises measurements from thermistor (SBE56) mounted on the Mooring Dirigibile Italia (MDI), which is managed by the Institute of Polar Sciences of the National Research Council (CNR). The mooring is placed in the Kongsfjorden, Svalbard Island, since September 2010 and the thermistor is placed at the nominal depths between 51 and 59 m and is operative from September 2012. This dataset is also part of the SIOS-Svalbard Integrated Arctic Earth Observing System, developed to observe the impacts of climate change, including the rapid loss of sea ice cover, the retreat of local glaciers, and the Atlantification of Arctic seas. Measured properties are: sea-water temperature. The acquisition of this time series data is still ongoing and will continue, bolstered by the inclusion of this infrastructure within the framework of the Italian PNRR project ITINERIS. This ensures sustained data collection and further enhances our understanding of the observed environmental changes.

The automated station to measures snow cover is operating at the Amundsen-Nobile Climate Change Tower since 2010, which is in a tundra site almost flat, located in the Kolhaugen area. The station is part of a complex infrastructure where multi-disciplinary observations are routinely performed. Data were collected using an ultrasonic distance sensor. This activity is carried out in the framework of the SnowCorD project (SIOS Core Data).

Terrestrial Photography ApplicationS on Snow covEr in Svalbard (PASSES) Project start: 2018-04-15 - end: 2021-12-31 The purpose of this activity is the development of a new snow product focused on the estimation of the fraction of snow cover in selected sites at different spatial resolutions. This dataset will be aimed to support the estimation of cryospheric information using remotely sensed data, with a particular attention to data obtained in the framework of the Copernicus program. The availability of this dataset in a natural laboratory such as Svalbard islands will support the reduction of the gap between remotely sensed data and modeling activities. This added value will be very important considering the higher spatial resolution of the sensors recently deployed. The dataset will be based on re-using data obtained from public repositories such as the digital elevation model of Svalbard, the available webcam imageries in Svalbard and satellite products from Landsat, Sentinel and MODIS missions. All the available data will be integrated in order to estimate the fraction of snow cover, at different spatial resolutions, for each satellite mission. These estimations, computed at different sites in Svalbard islands, will offer the opportunity to better integrate results obtained by remote sensing with modeling and air-snow interactions studies. Particular attention will be devoted to the formalization of agreements with raw-data providers in case of not-public licensing policies.

This dataset comprises measurements from moored CTD instruments, collected by the Mooring Dirigibile Italia (MDI), which is managed by the Institute of Polar Sciences of the National Research Council (CNR). The data was gathered at Kongsfjorden, Svalbard Island, since 29 May 2016 . This dataset is also part of the SIOS-Svalbard Integrated Arctic Earth Observing System, developed to observe the impacts of climate change, including the rapid loss of sea ice cover, the retreat of local glaciers, and the Atlantification of Arctic seas. Measured properties are: sea-water pressure, temperature, potential temperature, practical salinity, density, turbidity, fluorescence, PAR and dissolved oxygen in sea-water. The acquisition of this time series data is still ongoing and will continue, bolstered by the inclusion of this infrastructure within the framework of the Italian PNRR project ITINERIS. This ensures sustained data collection and further enhances our understanding of the observed environmental changes.

The automated nivological station was installed in November 2020 in a flat area over the tundra about 80 meters far from the Gruvebadet Atmospheric Laboratory and nearby a snow sampling site from where weekly snow samples are collected for chemical analysis. Sensors (NESA LU06) have been calibrated by their companies before installation and are connected to a datalogger for continuous acquisition. For all the parameters, data are logged with 10-minute time resolution and then averaged over 1 hour. This activity is carried out by the Aldo Pontremoli Centre part of the Joint Research Agreement ENI-CNR, in the framework of the SnowCorD project (SIOS Core Data).

A long-term climate manipulation experiment has been ongoing since 2014 at the REMUS site (Responses of Microbes in Upper Soil Horizons to Environmental Manipulations). Twenty-four open-top chambers (OTCs) were installed to simulate warmer ground temperatures and increased precipitation. To mimic enhanced rainfall, irrigation is applied twice a year, at the end of June and August. The transparent OTCs create an average ground temperature increase of approximately 1°C in the treated plots. The site is located about 11 Km from Ny-Ålesund at Kongsfjordneset (78.96661°N 11.47576°E) on the Brøgger Peninsula. In total, 48 plots with different plant species have been selected for the study. Of these, 24 are equipped with OTCs, while the remaining 24 are irrigated, with half of the irrigated plots also containing OTCs (12 with OTCs, 12 without). The REMUS site is registered on the Research in Svalbard Portal under ID 6921. This site is part of the International Tundra Experiment (ITEX), a global research initiative aimed at understanding the responses of tundra plant species through simple manipulation and transplant experiments conducted across multiple Arctic and alpine sites.

temperature, electrical conductivity, hydrometric level measured in piezometers located near CCT (Ny-Alesund)

This dataset comprises measurements from a moored CTD instruments, collected by the Krossfjord Italian Mooring (KIM), which is managed by the Institute of Polar Sciences of the National Research Council (CNR). The data was gathered in the Krossfjord, Svalbard Island, since September 2020. This dataset is also part of the SIOS-Svalbard Integrated Arctic Earth Observing System, developed to observe the impacts of climate change, including the rapid loss of sea ice cover, the retreat of local glaciers, and the Atlantification of Arctic seas. Mesured properties: seawater pressure, temperature, conductivity, salinity, density, oxygen concentration. The acquisition of this time series data is still ongoing and will continue, bolstered by the inclusion of this infrastructure within the framework of the Italian PNRR project ITINERIS. This ensures sustained data collection and further enhances our understanding of the observed environmental changes.

The Brøgger peninsula located in the north-western sector of Svalbard, is rich in shallow lakes, very different in morphology, height from sea level, composition of lake sediments, seasonal snow cover and presence/absence of migratory avian fauna in their catchment areas . In 2022, as part of the EcoClimate project (PI Prof. Edoardo Calizza), the research unit of the Institute of Polar Sciences of Messina set up a first series of sensors (Temperature; light) in 8 lakes spatially distributed at different heights from the sea and with different inputs of organic and inorganic substance. The observatory is currently in its second year of measurements.