Extreme values of snow-related variables in Mediterranean regions: trends and long-term forecasting in Sierra Nevada (Spain)
Other literature type
Pérez-Palazón, M. J.
Perales, J. M.
Polo, M. J.
Mountain areas in Mediterranean regions constitute key monitoring points for
climate variability and its impacts, but long time datasets are not always
available due to the difficult access to high areas, relevant for capturing
temperature and precipitation regimes, and the predominance of cloudy remote
sensing images during the snow season. Sierra Nevada National Park (South
Spain), with altitudes higher than 3500 m a.s.l., is part of the Global
Change in Mountain Regions network. Snow occurrence just 40 km from the
seaside determines a wide range of biodiversity, a snowmelt fluvial regime,
and the associated ecosystem services. This work presents the local trend
analysis of weather variables at this area together with additional
snow-related variables. For this, long term point and distributed
observations from weather stations and remote sensing sources were studied
and used as input and calibration datasets of a physically based snow model
to derive long term series of mean and maximum daily fraction of snow covered
area, annual number of days with snow, annual number of days with
precipitation, mean and maximum mean daily snow water equivalent, and
snowmelt and evaporation volumes. The joint analysis of weather and snow
variables showed a decrease trend in the persistence and extent of the snow
cover area. The precipitation regime, rather than the temperature trend,
seems to be the most relevant driver on the snow regime forcing in
Mediterranean areas. This poses a constraint for rigorous scenario analysis
in these regions, since the precipitation pattern is poorly approximated by
climatic models in these regions.