MOSSO_SnowPhysics&Chemistry_Annual_2009-2020

Abstract

The dataset provides information about the physical and chemical characteristics of the snowpack. Every year, a snow profile is open and sampled before the beginning of the melting season, close to the Istituto Scientifico Angelo Mosso (45°52'31.27"N, 7°52'17.09"E, elevation: 2900 m a.s.l.). Data are available for the years 2009 and 2010, and the period 2014-2020 (2016 was not analysed). Snow depth and density are measured, and snow water equivalent (SWE) is calculated. The analysed snow chemical parameters are: pH, electrical conductivity (EC), N-NH4, and N-NO3 (period 2009, 2010, 2014-2020); dissolved organic carbon (DOC), total dissolved nitrogen (TDN), and dissolved organic nitrogen (DON) (period 2014-2020); cations (Ca, Mg, Na, K) (years 2009, 2010, 2015); anions (S-SO4, N-NO2, P-PO4, Cl) (years 2009, 2010, 2015); trace elements (Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Rb, Si, Ti, V, Zn) (year 2015).

Method Description

Snow profiles are described following the AINEVA (Interregional Association for Snow and Avalanches) procedure (Cagnati 2003, Strumenti di misura e metodi di osservazione nivometeorologici: manuale per i rilevatori dei Servizi di previsione valanghe, Associazione Interregionale Neve e Valanghe, Trento). Snow density is measured by sampling and weighing 50-cm sections of the snow column with a snow measuring cylinder. The chemical analyses are performed in the laboratory on filtered samples (0.45 μm, nylon). For trace-element analyses, an aliquot of the filtered samples is acidified to pH<2 with hydrochloric acid, purified by sub-boiling distillation. pH is measured potentiometrically using a WTW-InoLab 7110 pH-meter equipped with Hamilton GelGlass electrode. EC at 20°C is measured using a Crison - Micro CM 2201. N-NH4 is determined spectrophotometrically (Spectrophotometer U-2000, Hitachi, Tokyo, Japan) by a modified Berthelot method involving reaction with salicylate in the presence of alkaline sodium dichloroisocyanurate (Crooke and Simpson 1971, https://doi.org/10.1002/jsfa.2740220104). N-NO3 is determined spectrophotometrically by the Greiss reaction as described by Mulvaney (1996, ISBN-10: ‎ 0891188258; ISBN-13: ‎ 978-0891188254) and modified by Cucu et al. (2014, https://doi.org/10.1007/s00374-013-0893-4). DOC and TDN are determined by a TOC analyzer (Elementar, Vario TOC, Hanau, Germany). DON is determined as the difference between TDN and inorganic nitrogen (N-NH4 + N-NO3). Cations are determined by flame atomic absorption spectroscopy (Perkin Elmer AAnalyst 400, Waltham, Massachusetts, USA). Anions are determined by ion chromatography (Dionex DX-500, Sunnyvale, California, USA). Trace elements are determined by inductively coupled plasma-sector field mass spectrometry (Thermo Finnigan Element 2, Bremen, Germany).

Instrumentation

WTW-InoLab 7110 pH-meter equipped with Hamilton GelGlass electrode (pH)

Crison - Micro CM 2201 (EC)

Spectrophotometer U-2000, Hitachi, Tokyo, Japan (N-NH4 and N-NO3)

Elementar, Vario TOC, Hanau, Germany (DOC and TDN)

Perkin Elmer AAnalyst 400, Waltham, Massachusetts, USA (cations)

Dionex DX-500, Sunnyvale, California, USA (anions)

Thermo Finnigan Element 2, Bremen, Germany (trace elements)