In recent decades, Svalbard's climate has undergone significant changes. However, amidst a nearly constant warming trend, 2020 emerged as an anomaly, marked by unusually low temperatures, a strong polar vortex, and extensive sea ice coverage throughout the winter season. Two sampling campaigns were conducted in the Gruvebadet Snow Research Site (GSRS) in Kongsfjorden (Ny-Ålesund, Svalbard): one during the “cold” 2020 (October 2019 to May 2020) and the other during a “warm” year (October 2018 to May 2019). These campaigns aimed to investigate the potential effects of the distinct climatic conditions on the biogeochemical cycle of mercury (Hg). Mercury, a toxic element, has been extensively studied in polar regions yet uncertainties remain to address changes in the Hg biogeochemical cycle under shifting climatic and atmospheric conditions. By comparing data from the “warm” and “cold” years, this study investigates how factors such as temperature and sea ice modulated Hg deposition patterns. We noted an increase in bromine concentrations in snow during the “cold” year, and in particular in the non-sea-salt component of Br (nssBr and Brenr), which is likely associated to sea ice emissions. However, we do not observe a systematic impact of high bromine on Hg in snow or atmosphere. In both “warm” and “cold” years, Atmospheric Mercury Depletion Events (AMDEs) not followed by Hg deposition on snow are associated with high solar radiation, suggesting possible photo-reduction of Hg in snow. GEM shows good correlation with temperature during all AMDEs, with no distinction between “warm” and “cold” years, suggesting that AMDEs are not directly controlled by absolute value of temperature.

The Svalbard Archipelago has undergone rapid warming in recent decades, increasing the frequency and intensity of Rain-on-Snow (ROS) events. While the physical and ecological consequences of ROS in the Arctic have been extensively documented, their role in modulating the atmospheric fate of emerging contaminants remains poorly understood. This study investigates the chemical signature of four ROS events during the 2023-24 field campaign in Ny-Ålesund (Kongsfjorden, Svalbard, Norway), focusing on the behaviour of emerging pollutants across pre-, during-, and post-event phases. By combining aerosol and wet deposition data with meteorological variables and air mass back-trajectories, we explore the potential of ROS to act as removal mechanisms for benzothiazole derivatives, tris(2-carboxyethyl) phosphine (TCEP) as flame retardant, pesticides, and haloacetic acids. The results highlight a substantial variability in contaminant patterns across events and suggest the influence of synoptic-scale air mass origin and local meteorological conditions. Diagnostic ratios and inorganic ion proxies provide insight into possible atmospheric transformation pathways and transport processes. This study provides the first detailed chemical characterisation of aerosol and depositions during Rain-On-Snow events, establishing a preliminary framework to better understand the complex interactions between ROS and contaminant cycling in a warming Arctic. This work contributes to ongoing efforts to clarify the mechanisms of atmospheric scavenging under changing climate conditions.

The Svalbard Archipelago has experienced rapid warming in recent decades, leading to an increased frequency and intensity of Rain-on-Snow (ROS) events. While the physical and ecological impacts of ROS in the Arctic are well documented, their potential role in influencing the atmospheric fate of emerging contaminants remains largely unexplored. This study examines the chemical signature of four ROS events observed during the 2023–24 field campaign in Ny-Ålesund (Kongsfjorden, Svalbard, Norway), with particular attention to the behaviour of emerging pollutants before, during, and after each event. By integrating aerosol and wet deposition measurements with meteorological parameters and air-mass back-trajectory analyses, we assess the capacity of ROS events to act as removal processes for benzothiazole derivatives, tris(2-carboxyethyl)phosphine (TCEP) used as a flame retardant, pesticides, and haloacetic acids. Our results reveal marked variability in contaminant patterns across events, indicating a strong influence of synoptic-scale air mass origins and local meteorological conditions. Diagnostic ratios and inorganic ion tracers further provide insights into potential atmospheric transformation pathways and transport mechanisms. This study presents the first detailed chemical characterisation of aerosols and depositions associated with Rain-on-Snow events, offering a preliminary framework to better understand the interactions between ROS processes and contaminant cycling in a rapidly warming Arctic. This work contributes to ongoing efforts to elucidate atmospheric scavenging mechanisms under changing climate conditions.

The mechanisms of drainage of supraglacial lakes are not yet fully understood. Here we present an indepth study of drainage characteristics of a 21km^2 large supraglacial lake in Northeast Greenland from its genesis in mid 1990s to 2023. We discuss the fracture modes involved in drainage and compare this to simulated principal stress fields. A particular focus of the presentation is the formation of gullies. Using high resolution optical satellite imagery (WV2 and Planet), we detect fracture networks at the surface. We find evidence for reactivation of former gullies in subsequent lake drainage events. In addition we present viscoelastic modelling of gullies at the surface that support the continued existence of open gullies at the surface. In vertical direction, we surveyed the glacier using airborne radio echo sounding in 2016, 2018 and 2021. This data reveals englacial channels and their remnants over the entire live span of the lake.

The increasing demand for critical raw materials (CRMs), driven by global energy transition, underscores the need for innovative approaches to identify secondary resources, such as mining residues. Mining residues, often overlooked during initial mining activities, now represent valuable sources of raw materials thanks to technological advancements, including hyperspectral remote sensing. This study investigates the potential of hyperspectral satellite imagery to detect and map CRMs in mining residues of the abandoned Sidi Bou Azzouz mine in Morocco. The proposed approach is based on the integration between satellite data, field spectroscopy, chemical, and mineralogical analyses in a strong multi-scale and interdisciplinary framework. The integration between advanced laboratory techniques, including LIBS, XRF, XRPD, and SEM-EDS, was employed to enhance hyperspectral data interpretation. The integration of remote sensing and laboratory results provided a comprehensive understanding of mineral composition, confirming the effectiveness of hyperspectral methods for characterizing heterogeneous surface deposits. This research demonstrates the potential of hyperspectral observations to identify valuable raw materials and to map them using PRISMA imagery in abandoned mining residues, offering a tool useful for planning cost-effective and sustainable solutions aimed at answering the growing demand for CRMs crucial to industrial competitiveness and sustainable growth.

The snow season in the Svalbard archipelago generally lasts 6–10 months a year and significantly impacts the regional climate, glaciers mass balance, permafrost thermal regime and ecology. Due to the lack of long-term continuous snowpack physical data, it is still challenging for the numerical snow physics models to simulate multi-layer snowpack evolution, especially for remote Arctic areas. To fill this gap, in November 2020, an automated nivometric station (ANS) was installed ∼1 km Southwest from the settlement of Ny-Ålesund (Spitzbergen, Svalbard), in a flat area over the lowland tundra. It automatically provides continuous snow data, including NIR images of the fractional snow-cover area (fSCA), snow depth (SD), internal snow temperature and liquid water content (LWC) profiles at different depths with a 10 min time resolution. Here we present the first-year record of automatic snow preliminary measurements collected between November 2020 and July 2021 together with weekly manual observations for comparison. The snow season at the ANS site lasted for 225 days with an annual net accumulation of 117 cm (392 mm of water equivalent). The LWC in the snowpack was generally low (<4%) during wintertime, nevertheless, we observed three snow-melting events between November and February 2021 and one in June 2021, connected with positive temperature and rain on snow events (ROS). In view of the foreseen future developments, the ANS is the first automated, comprehensive snowpack monitoring system in Ny-Ålesund measuring key essential climate variables needed to understand the seasonal evolution of the snow cover on land.

The geospatial model here presented estimates the permafrost active layer thickness (ALT) over the entire Arctic in the last 20 years, and it is based on the spatial and temporal oscillations measured by satellite-based essential variables associated with the thermal state of permafrost. The model integrates the climate and soil components, such as the land surface temperature, the snow depth water equivalent, and the mid-summer albedo, with the structural and functional descriptors of Arctic tundra biome such as the fraction of absorbed photosynthetically active radiation. The distribution of estimated ALT varies according to the vegetation classes (mosses and lichens or grasses and shrubs), but a general increase has been estimated across the whole Arctic tundra region, with rates of up to 2 cm/year.

The gridded datasets is a ensembled product obtained since 2020 processing imagery acquired by different time-lapse cameras located at the Zeppelin Observatory, at the Gruvebadet Snow Research Site and at the Amundsen-Nobile Climate Change Tower.

Remarkable developments in the fields of earth observation (EO) satellites and remote sensing (RS) technology over the past four decades have substantially contributed to spatial, spectral, and temporal sampling [...]

The occurrence of extreme warm events in the Arctic has been increasing in recent years in terms of their frequency and intensity. The assessment of the impact of these episodes on the snow season requires further observation capabilities, where spatial and temporal resolutions are key constraints. This study targeted the snow season of 2022 when a winter rain-on-snow event occurred at Ny-Ålesund in mid-March. The selected methodology was based on a multi-scale and multi-platform approach, combining ground-based observations with satellite remote sensing. The ground-based observation portfolio included meteorological measurements, nivological information, and the optical description of the surface in terms of spectral reflectance and snow-cover extent. The satellite data were obtained by the Sentinel-2 platforms, which provided ten multi-spectral acquisitions from March to July. The proposed strategy supported the impact assessment of heat waves in a periglacial environment, describing the relation and the timing between rain-on-snow events and the surface water drainage system. The integration between a wide range of spectral, time, and spatial resolutions enhanced the capacity to monitor the evolution of the surface water drainage system, detecting two water discharge pulsations, different in terms of duration and effects. This preliminary study aims to improve the description of the snow dynamics during those extreme events and to assess the impact of the produced break during the snow accumulation period.

EDITORIAL article Front. Earth Sci., 18 August 2023Sec. Cryospheric Sciences Volume 11 - 2023 | https://doi.org/10.3389/feart.2023.1266810

The ongoing climate warming is affecting high-elevation areas, reducing the extent and the duration of glacier and snow covers, driving a widespread greening effect on the Alpine region. The impact assessment requires therefore the integration of the geomorphological context with altitudinal and ecological features of the study areas. The proposed approach introduces chronologically-constrained zones as geomorphological evidence for selecting deglaciated areas in the alpine and non-alpine belts. In the present study, the protected and low-anthropic-impacted areas of the Gran Paradiso Group (Italian Western Alps) were analysed using Landsat NDVI time series (1984–2022 CE). The obtained results highlighted a progressive greening even at a higher altitude, albeit not ubiquitous. The detected NDVI trends showed, moreover, how the local factors trigger the greening in low-elevation areas. Spectral reflectance showed a general decrease over time, evidencing the progressive colonisation of recently deglaciated surfaces. The results improved the discrimination between different greening rates in the deglaciated areas of the Alpine regions. The geomorphological-driven approach showed significant potential to support the comprehension of these processes, especially for fast-changing areas such as the high mountain regions.

The data value of hyperspectral measurements on ice and snow cover is strongly impacted by the availability of data services, where spectral libraries are integrated to detailed descriptions of the observed surface cover. For snow and ice cover, we present an updated version of the Snow/Ice Spectral Archive (SISpec 2.0), which has been integrated into a web portal characterized by different functionalities. The adopted metadata scheme features basic geographic data, information about the acquisition setup, and parameters describing the different surface types. While the implementation of the IACS Classification of Seasonal Snow on the Ground is the core component for snow cover, ice cover is approached using different parameters associated with its surface roughness and location. The web portal is not only a visualization tool, but also supports interoperability functionalities, providing data in the NetCDF file format. The availability of these functionalities sets the foundation for sharing a novel platform with the community and is an interesting tool for calibrating and validating data and models.

Integrative and Comprehensive Understanding on Polar Environments (iCUPE) project developed 24 novel datasets utilizing in-situ observational capacities within the Arctic or remote sensing observations from ground or from space. The datasets covered atmospheric, cryospheric, marine, and terrestrial domains. This paper connects the iCUPE datasets to United Nations’ Sustainable Development Goals and showcases the use of selected datasets as knowledge provision services for policy- and decision-making actions. Inclusion of indigenous and societal knowledge into the data processing pipelines enables a feedback mechanism that facilitates data driven public services.

This study aims to set up a metadata profile useful for preparing an interoperable dataset containing snow and ice hyperspectral measurements. The proposed Snow and Ice Spectral Library (SISpec) scheme was prepared for sharing a data collection focused on Antarctica, including 70 observations. Following the perspective to grant “open access” to such a dataset, we found a compromise between the ERC (European Research Council) guidelines, the FAIR (Findability, Accessibility, Interoperability, and Reuse) Data principles defined by the RDA (Research Data Alliance), and the GEO (Group on Earth Observation) Data Sharing Principles. The ISO (International Organization for Standardization) standard 19115 was chosen as the standard framework for describing SISpec. When the available metadata scheme was not sufficient or suitable, metadata extensions or new detailed metadata components were created to be compliant with the ISO 19115 standard. We also considered the INSPIRE (Infrastructure for Spatial Information in Europe) requirements and the result is a metadata model that can be useful to share SISpec metadata both in the European and international contexts. Particularly detailed metadata sections and elements were created for describing spectral signatures and microphysical snow parameters.

The automated station 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.

Atmospheric measurements of nitrogen oxides (NOx = NO + NO2), ozone (O3) and other constituents were carried out during three field campaigns (29 March–30 April 2010, 1–26 April 2011, 18 May–8 October 2015) at Ny-Ålesund. The study focused on the variability of important O3 precursors, such as NOx, in the Arctic troposphere, and on the impact from anthropogenic sources on their measured concentrations: higher NO and NO2 levels were mostly associated with the lowest wind speeds and northern directions, indicating local pollution. Long-range transported sources from Russia and Europe were also identified with an occurrence of high NOx levels. Several ozone depletion events were observed and associated to winds blowing from the north-west direction (Arctic Ocean). Most of these events were connected to the lower NO and NO2 concentrations. Measurements of halogen and low molecular weight carbonyl compounds in 2010 and 2011, respectively, showed variable effects during the ozone depletion events. Other data, such as high time-resolved radon progeny measurements, were used in 2015 to identify source tracking and transport of air masses, local effects and atmospheric stability dynamics that could influence the NOx concentrations at Ny-Ålesund.

Polar areas are the most sensitive targets of climate change. From this perspective, the continuous monitoring of the cryosphere represents a critical need, which, now, we can only partially supply with specific satellite missions. The integration between remote-sensed multi-spectral images and field data is crucial to validate retrieval algorithms and climatological models. The optical behavior of snow, at different wavelengths, provides significant information about the microphysical characteristics of the surface in addition to the spatial distribution of snow/ice covers. This work presents the unmanned apparatus installed at Ny Ålesund (Svalbard) that provides continuous spectral surface albedo. A narrow band device was compared to a full-range system, to remotely sensed data during the 2015 spring/summer period at the Amundsen-Nobile Climate Change Tower. The system was integrated with a camera aimed to acquire sky and ground images. The results confirmed the possibility of making continuous observations of the snow surface and highlighted the opportunity to monitor the spectral variations of snowed surfaces during the melting period.

The monitoring of surface albedo using radiometric measurements is a simple but effective way to study variations in snow cover and melt timing in the high northern latitudes, where there is a clear indication of warming in response to the changing global climate. In this paper, we investigate these phenomena in the Northwest region of Svalbard using a 40-year record, combining previous data from 1981 to 1997, radiation measurements from the Baseline Surface Radiation Network (BSRN) station since 1993, and the Amundsen Nobile Climate Change Tower (CCT) since 2009. A methodology has been developed to estimate the start, duration, and end date of the spring snow melt. This has been applied to the integrated dataset for the period 1981 to 2019. Our results are in good agreement with qualitative information on snow persistence provided by webcam images archived since 2000. The date of snow melt has advanced at a rate of about 3 days per decade during the period of study, from Julian calendar date (doy) 180 in the early 1980s to 165–170 in the late 2010s. There is indication the trend has accelerated since 2010. The footprint of the radiation measurements is a crucial factor in the evaluation of surface albedo; the larger the area within the field of view of the instrument, the more representative is the measure. The assimilated 40-year dataset will provide a base for future monitoring of snow persistence at Ny-Ålesund as the climate continues to change in the region. Our work highlights the importance of technical improvements made in measurement systems and combining different techniques to monitor surface albedo. In particular, terrestrial photography, combined with broadband radiation measurements, will contribute to increased knowledge of underlying processes that determine the surface energy budget in the Arctic region. In addition, the combined ground-based measurements can be used to validate those derived from space-born platforms.