A study published in the International Journal of Climatology, in which several researchers of the UB participated, analysed for the first time the recent evolution of snow at high levels in the Catalan Pyrenees. The study shows that over the last twenty years, at more than 2,000 meters high, the snow has not decreased but there has been an increase of snow-shape rain during the winter.
The paper evaluated the tendencies of snow accumulation from 2000 to 2020, and from 1985 to 2020 in the case of the meteorological station in Núria (Vall de Núria, 1,971 meters). The study focused on the meteorological records of the mountain stations of the Meteorological Service of Catalonia (SMC), located at more than 2,000 meters high.
At more than 2,000 meters high, the study detected an increase of snow-shaped rain during winter. This tendency has been observed both in 1985 and early 2000, until 2020. During the rest of the season, many stations show a slightly positive tendency, while other stations located facing north in the western Pyrenees, show a slightly negative tendency regarding snow accumulation.
Regarding the relation between this increase of snow-like precipitations and the current context of climate change, the authors note that "Although the Mediterranean basin is one of the areas that has warmed the most over the recent decades, as a result from the increase in greenhouse gases in the atmosphere, at the altitude in which the study was focused on, temperatures are low enough during the winter months so as to cause snow-like rain from December to March". According to the experts, the snow pack -accumulated snowresponds to this presence of precipitations.
Regarding the causes of the increase in snow rains during the studied period, the phenomenon could respond to the "variability in the rainfall regime, typical of the Mediterranean climate". In conclusion, "the data from the study show the climate sensitiveness of the Catalan Pyrenees, with sectors where the snow-like rain increased over the last decades despite the global climate context".
Regarding its evolution in the future, researchers note that the climate scenarios predicted by the international climate reports point to "a decrease in the length of the snow pack (beginning and end of the season), more stressed at low and medium heights, mainly due to global warming". The latest projections by the State Meteorological Agency for the western Pyrenees predict a slight increase in rainfalls (around 10%). "However, -note the authors-, we need to continue to gather data and expand them to sectors of the Pyrenees where the availability of data is scarce, to monitor the effects of global warming in the mountain landscape and the consequences it has on social and economic activities that depend on the snow".
The study reveals how the stations that are located in the northern side of the western Catalan Pyrenees accumulate twice the snow per season than those located in the western side of the Catalan Pyrenees. In this sense, the orographic configuration plays an important role.
The study results from the joint project by experts and researchers led by the Research Group Antarctic, Arctic and Alpine Environments ( ANTALP ) of the University of Barelona. The project has been coordinated by Josep Maria Bonsoms (CESBIO, Universitat de Tolosa, CNES/CNRS/IRD/UPS); Sergi Gonzàlez (expert and researcher at the State Meteorological Agency); Marc Prohom and Pere Esteban (experts at SMC and members of the Climatology Group at the Department of Geography of the UB); Ferran Salvador-Franch (lecturer and researcher of Physical Geography at the Department of Geography of the UB); Juan Ignacio López-Moreno (researcher at the Pyrenean Institute of Ecology, IPE-CSIC) and Marc Oliva (Ramón y Cajal researcher and lecturer at the Department of Geography of the UB).
Bonsoms, J.; González, S.; Prohom, M.; Esteban, P.; Salvador-Franch, F.; López-Moreno, J. I. i Oliva, M. (2021). "Spatio-temporal patterns of snow in the Catalan Pyrenees (NE Iberia)" . International Journal of Climatology, April, 2021. DOI: doi.org/10.1002/joc.7147