ESOLIP – estimate of solid and liquid precipitation at sub-daily time resolution by combining snow height and rain gauge measurements

Abstract

Abstract. Measuring precipitation in mountain areas is a demanding task, but essential for hydrological and environmental themes. Especially in small Alpine catchments with short hydrological response, precipitation data with high temporal resolution are required for a better understanding of the hydrological cycle. Since most climate/meteorological stations are situated at the easily accessible bottom of valleys, and the few heated rain gauges installed at higher elevation sites are problematic in winter conditions, an accurate quantification of winter (snow) precipitation at high elevations remains difficult. However, there are an increasing number of micro-meteorological stations and snow height sensors at high elevation locations in Alpine catchments. To benefit from data of such stations, an improved approach to estimate solid and liquid precipitation (ESOLIP) is proposed. ESOLIP allows gathering hourly precipitation data throughout the year by using unheated rain gauge data, careful filtering of snow height sensors as well as standard meteorological data (air temperature, relative humidity, global shortwave radiation, wind speed). ESOLIP was validated at a well-equipped test site in Stubai Valley (Tyrol, Austria), comparing results to winter precipitation measured with a snow pillow and a heated rain gauge. The snow height filtering routine and indicators for possible precipitation were tested at a field site in Matsch Valley (South Tyrol, Italy). Results show a good match with measured data because variable snow density is taken into account, which is important when working with freshly fallen snow. Furthermore, the results show the need for accurate filtering of the noise of the snow height signal and they confirm the unreliability of heated rain gauges for estimating winter precipitation. The described improved precipitation estimate ESOLIP at sub-daily time resolution is helpful for precipitation analysis and for several hydrological applications like monitoring systems and rainfall-runoff models.

Evaluating the present annual water budget of a Himalayan headwater river basin using a high‐resolution atmosphere‐hydrology model

“…This disparity may partly arise due to the fact that there are no measurements in this study higher than 2000 m altitude and also due to the fact that the regional precipitation gauges used in this study were not designed to appropriately measure snowfall. Reliable snowfall measurements are scarce over the Himalayan region as snowfall is generally underestimated by surface rain gauges [Mair et al, 2013;Hirabayashi et al, 2008;Judson and Doesken, 2000]. The APHRODITE data, which are based on gauge measurements, also suffer from limited coverage and appear to underestimate precipitation in this region.…”

“…This is important because little to no long-term data from weather stations exist at elevations over 4800 m asl [Winiger et al, 2005;Maussion et al, 2011;Böhner and Lucarini, 2015]. Even when available, reliable snowfall measurements are scarce as snowfall is generally underestimated by surface rain gauges [Mair et al, 2013;Hirabayashi et al, 2008;Judson and Doesken, 2000]. These data are important for understanding the local-regional hydroclimate.…”

Twenty-first-century glacio-hydrological changes in the Himalayan headwater Beas River basin

“…Earlier climate change impact studies have not presented a coherent view of the largest source of uncertainty in essential hydrological variables, especially the evolution of streamflow and derived characteristics in glacier-fed river basins over high mountainous ungauged or poorly gauged areas, like the Himalayan region (Hasson et al, 2014;Li et al, 2016;Lutz et al, 2016;Ali et al, 2015). At present, a complete understanding of the hydroclimatic variability is also a challenge in the Himalayan basins due to a lack of in situ observations (Maussion et al, 2011) and incomplete or unreliable records (Hewitt, 2005;Bolch et al, 2012;Hartmann and Andresky, 2013). Palazzi et al (2013) compared six gridded precipitation products to simulation results from a global climate model, EC-Earth.…”

Tracer-based analysis of spatial and temporal variations of water sources in a glacierized catchment

“…For data analysis, the average values from these stations were used. Winter precipitation in these stations was estimated using automatic recorded snow height data from a nearby station of the EURAC network in a wind-sheltered location at the same elevation of the M4 station, following the approach suggested by Mair et al (2013). Water stage in the main Saldur channel was recorded every 10 min through pressure transducers at the catchment outlet (1632 m a.s.l., station run by the Hydrographic Office of the Province of Bozen-Bolzano), and at two natural sections, laterally well confined by large immobile boulders, named Lower Stream Gauge (S3-LSG, 2150 m a.s.l.)…”