Articles | Volume 9, issue 2
https://doi.org/10.5194/essd-9-573-2017
https://doi.org/10.5194/essd-9-573-2017
Review article
 | 
15 Aug 2017
Review article |  | 15 Aug 2017

Snow observations in Mount Lebanon (2011–2016)

Abbas Fayad, Simon Gascoin, Ghaleb Faour, Pascal Fanise, Laurent Drapeau, Janine Somma, Ali Fadel, Ahmad Al Bitar, and Richard Escadafal

Abstract. We present a unique meteorological and snow observational dataset in Mount Lebanon, a mountainous region with a Mediterranean climate, where snowmelt is an essential water resource. The study region covers the recharge area of three karstic river basins (total area of 1092 km2 and an elevation up to 3088 m). The dataset consists of (1) continuous meteorological and snow height observations, (2) snowpack field measurements, and (3) medium-resolution satellite snow cover data. The continuous meteorological measurements at three automatic weather stations (MZA, 2296 m; LAQ, 1840 m; and CED, 2834 m a.s.l.) include surface air temperature and humidity, precipitation, wind speed and direction, incoming and reflected shortwave irradiance, and snow height, at 30 min intervals for the snow seasons (November–June) between 2011 and 2016 for MZA and between 2014 and 2016 for CED and LAQ. Precipitation data were filtered and corrected for Geonor undercatch. Observations of snow height (HS), snow water equivalent, and snow density were collected at 30 snow courses located at elevations between 1300 and 2900 m a.s.l. during the two snow seasons of 2014–2016 with an average revisit time of 11 days. Daily gap-free snow cover extent (SCA) and snow cover duration (SCD) maps derived from MODIS snow products are provided for the same period (2011–2016). We used the dataset to characterize mean snow height, snow water equivalent (SWE), and density for the first time in Mount Lebanon. Snow seasonal variability was characterized with high HS and SWE variance and a relatively high snow density mean equal to 467 kg m−3. We find that the relationship between snow depth and snow density is specific to the Mediterranean climate. The current model explained 34 % of the variability in the entire dataset (all regions between 1300 and 2900 m a.s.l.) and 62 % for high mountain regions (elevation 2200–2900 m a.s.l.). The dataset is suitable for the investigation of snow dynamics and for the forcing and validation of energy balance models. Therefore, this dataset bears the potential to greatly improve the quantification of snowmelt and mountain hydrometeorological processes in this data-scarce region of the eastern Mediterranean. The DOI for the data is https://doi.org/10.5281/zenodo.583733.

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Short summary
Snowmelt plays a key role in the replenishment of the karst groundwater in Lebanon. The proper estimation of the water contained in the snowpack is one of Lebanon's most challenging questions. In this paper, we present continuous meteorological and snow course observations for the first time in the snow-dominated regions of Mount Lebanon. This new dataset can be used to feed an advanced snowpack model and is the first step towards a better evaluation of the snowmelt in Lebanon.