Evaluation of gridded precipitation for norway using glacier mass‐balance measurements

Abstract

The service seNorge (http://senorge.no) provides gridded temperature and precipitation for mainland Norway. The products are provided as interpolated station measurements on a 1 × 1 km grid. Precipitation gauges are predominantly located at lower elevations such as coastal areas and valleys. Therefore, there are large uncertainties in extrapolating precipitation data to higher altitudes, both due to sparsity of observations as well as the large spatial variability of precipitation in mountainous regions. Using gridded temperature and precipitation data from seNorge, surface mass balance was modeled for five Norwegian glaciers of different size and climate conditions. The model accounts for melting of snow and ice by applying a degree‐day approach and considers refreezing assuming a snow depth depended storage. Calculated values are compared to point measurements of glacier winter mass balance. On average for each glacier, modeled and measured surface mass‐balance evolutions agree well, but results at individual stake locations show large variability. Two types of problems were identified: first, grid data were not able to capture spatial mass balance variability at smaller glaciers. Second, a significant increase in the bias between model and observations with altitude for one glacier suggested that orographic enhancement of precipitation was not appropriately captured by the gridded interpolation.

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

“…The daily gridded temperature and precipitation were input data for the GSM module, which calculates both snow accumulation and meltwater runoff. A temperature-index approach (Hock, 2003;Engelhardt et al, 2012Engelhardt et al, , 2017 was used in the study for the calculation of melt in the conceptual GSM module. In the GSM module simulation, the precipitation shifts from rain to snow linearly within a temperature interval of T (Table 1).…”

Contribution of snow and glacier melt to discharge for highly glacierised catchments in Norway

“…The data are based on station measurements which are interpolated on a 1 km horizontal grid for all of mainland Norway on a daily basis from 1957 to the present (Mohr, 2008). Despite some weaknesses with the inter-and extrapolation of precipitation in mountainous regions, different evaluation studies (Mohr, 2009;Dyrrdal, 2010;Engelhardt et al, 2012;Saloranta, 2012) found the gridded data of seNorge to be suitable for mass-balance modelling especially due to its high spatial resolution. …”

“…Braun et al, 1994). Since the gridded precipitation data from seNorge for the glacier parts of all catchments (P g ) had already been evaluated in the study by Engelhardt et al (2012), we now used the calculated precipitation correction factors (F g ) from that study for the glacierised areas and calculated the correction factors for the precipitation (P ng ) of the non-glacierised parts (F ng ) of the catchments. The water balance equation for the glacierised and non-glacierised areas was then modified to…”

Hydrological drought types in cold climates: quantitative analysis of causing factors and qualitative survey of impacts

“…We used well-established data sets of catchments in Austria (Parajka and Blöschl, 2008;Merz et al, 2011;Haslinger et al, 2014) and Norway (Mohr and Tveito, 2008;Engelhadt et al, 2012;Fleig et al, 2013) that were thoroughly quality-checked and used in other scientific studies. However, measurement errors, uncertainties in the estimation of gridded data from station data, and issues of representativity can still occur, especially in mountainous catchments.…”