Comparing Measured Incoming Shortwave and Longwave Radiation on a Glacier Surface with Estimated Records from Satellite and Off-Glacier Observations: A Case Study for the Forni Glacier, Italy

Abstract

The development of methods for quantifying meltwater from glaciated areas is very important for better management of water resources and because of the strong impact of current and expected climate change on the Alpine cryosphere. Radiative fluxes are the main melt-drivers, but they can generally not be derived from in situ measures because glaciers are usually located in remote areas where the number of meteorological stations is very low. For this reason, focusing, as a case study, on one of the few glaciers with a supraglacial automatic weather station (Forni Glacier), we investigated methods based on both satellite records and off-glacier surface observations to estimate incoming short- and long-wave radiation at the glacier surface (SWin and LWin). Specifically, for SWin, we considered CM SAF SARAH satellite gridded surface solar irradiance fields and data modeled by cloud transmissivity parametrized from both CM SAF COMET satellite cloud fractional cover fields and daily temperature range observed at the closest off-glacier station. We then used the latter two data sources to derive LWin too. Finally, we used the estimated SWin and LWin records to assess the errors obtained when introducing estimated rather than measured incoming radiation data to quantify glacier melting by means of an energy balance model. Our results suggest that estimated SWin and LWin records derived from satellite measures are in better agreement with in situ observations than estimated SWin and LWin records parametrized from observations performed at the closest off-glacier station. Moreover, we find that the former estimated records permit a significantly better quantification of glacier melting than the latter estimated ones.

MOUNTAINPLAST: A New Italian Plastic Footprint with a Focus on Mountain Activities

“…Allen et al (2019) [19] suggested that fibers up to 750 µm and fragments ≤ 300 µm can reach remote areas through atmospheric transportation. Ambrosini et al (2019) [18] were the first to verify the presence of microplastics in an Alpine glacier environment (the Forni Glacier, a wide valley glacier located in the Italian Alps [20,21]), detecting concentrations comparable with those previously found in marine and coastal areas [18]. Crosta et al (2022) [22] found microplastics on other glaciers in the Italian Alps [22], suggesting the urgent necessity of actions to reduce the spread of microplastics in mountain glacierized areas.…”

Comparison of Surface Solar Irradiance from Ground Observations and Satellite Data (1990–2016) over a Complex Orography Region (Piedmont—Northwest Italy)

“…The analyses presented in this study have in fact highlighted that the comparison of surface solar irradiance records from different data sources is a complex issue that has to be performed, critically evaluating the strengths and the weaknesses of each of them in relation to the objectives of the analysis. For example, a study has shown that short-and long-wave satellite data can be successfully used on a glacier surface to estimate summer glacier melting if they are not available from on-glacier surface measurements [60], even if satellite data at high-elevations present some limitations.…”

Spatial distribution and stable isotopic composition of invertebrates uncover differences between habitats on the glacier surface in the Alps

“…1A). The detailed description of the Forni Glacier is provided in Azzoni et al (2016), Citterio et al (2007), and Senese et al (2020). We collected metazoans and cryoconite from cryoconite holes (Fig.…”