Snow Impurities in the Central Pyrenees: From Their Geochemical and Mineralogical Composition towards Their Impacts on Snow Albedo

Abstract

The aim of this work is to understand aerosol transfers to the snowpack in the Spanish Pyrenees (Southern Europe) by determining their episodic mass-loading and composition, and to retrieve their regional impacts regarding optical properties and modification of snow melting. Regular aerosol monitoring has been performed during three consecutive years. Complementarily, short campaigns have been carried out to collect dust-rich snow samples. Atmospheric samples have been chemically characterized in terms of elemental composition and, in some cases, regarding their mineralogy. Snow albedo has been determined in different seasons along the campaign, and temporal variations of snow-depth from different observatories have been related to concentration of impurities in the snow surface. Our results noticed that aerosol flux in the Central Pyrenees during cold seasons (from November to May, up to 12–13 g m−2 of insoluble particles overall accumulated) is much higher than the observed during the warm period (from June to October, typically around 2.1–3.3 g m−2). Such high values observed during cold seasons were driven by the impact of severe African dust episodes. In absence of such extreme episodes, aerosol loadings in cold and warm season appeared comparable. Our study reveals that mineral dust particles from North Africa are a major driver of the aerosol loading in the snowpack in the southern side of the Central Pyrenees. Field data revealed that the heterogeneous spatial distribution of impurities on the snow surface led to differences close to 0.2 on the measured snow albedo within very short distances. Such impacts have clear implications for modelling distributed energy balance of snow and predicting snow melting from mountain headwaters.

A Decrease in the Regulatory Effect of Snow-Related Phenomena in Spanish Mountain Areas Due to Climate Change

“…Radiation depends on multiple factors that are difficult to predict. Besides, other effects such as snow impurities affecting snow albedo may have a greater effect on melting than the radiation input itself [37].…”

Black carbon and dust alter the response of mountain snow cover under climate change

“…The relative impact of dust compared to the one of BC is higher for the South Pyrenees than for the Alps. This is explained by the regional patterns of African dust deposition that decreases with the distance to the North African coasts according to a south-north gradient (33) and by the general predominance of African over local sources in the total dust load (36). We can thus expect similarly large regional contrast in the impact of LAPs on snow cover in other mountainous regions.…”

Interaction of Air Pollution with Snow and Seasonality Effects

“…Field observation, laboratory-experimental, and modeling studies are included, along with environmental monitoring and source apportionment research of local, regional, or global relevance. The fieldwork covered in the articles was conducted in various types of locations: urban sites (e.g., the cities of Chengdu, Gucheng [1], Helsinki [2], Montreal [3], and Moscow [4]); small cities and rural areas (e.g., Yulin, Huimin, and Zhengzhou [1], Tien Shan [5], Valday [6], and "36 sites on a 2800 km submeridional profile from the city of Barnaul to Salekhard" [7]); industrial [6]; remote (e.g., the Arctic, Antarctic [8], and Tibetan Plateau [9]); and other locations (e.g., along highways [10] and in the mountains [11]).…”

“…The articles collected in this Special Issue focus on the following aspects of the interaction of air pollution with snow and the effects of seasonality: (1) the impact of deposited air pollutants on the snow albedo [2,11,12], (2) the composition and properties of particulate and volatile air pollutants detected in snow [4,7,8,11], (3) links with the sources and impact assessment, including, more specifically, seasonality of black carbon in the air and snow [1,2,5,9,12], (4) metals and metalloids in snow [4,6], (5) radioactive isotopes in snow [10], (6) snowpack pollution as an indicator of atmospheric pollution [1,[6][7][8]10,12], (7) photochemistry of compounds released due to interactions with anthropogenic particles that became mixed with snow [3], and (8) the effect of snow on greenhouse gas fluxes from the underlying peat [13].…”

“…Pey and colleagues [11] explored the aerosol deposition from the atmosphere to the snowpack in the Spanish Pyrenees and examined its impact on the optical properties of snow and the snow melting processes. They found the impact on the snow albedo significant enough to be considered in modeling distributed energy balance and snowmelt predictions.…”