Numerical simulations of precipitation in the complex terrain of Iceland Comparison with glaciological and hydrological data

Rögnvaldsson, Ólafur; Jonsdottir, Jona Finndis; Ólafsson, Haraldur

doi:10.1127/0941-2948/2007/0174

Cited by 24 publications

(16 citation statements)

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“…The model's meteorological input data, i.e., precipitation, evaporation and air temperature fields, was provided by the PSU/NCAR MM5 numerical weather model (Grell et al, 1994) driven by initial and boundary data from the European Centre for Medium-range Weather Forecasts (ECMWF). The simulated precipitation and the resulting river discharge values given by WaSiM compared favourably with hydrological records (Rögnvaldsson et al, 2007).…”

Section: Icelandic River Runoffmentioning

confidence: 57%

The circulation of Icelandic waters – a modelling study

et al. 2013

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Abstract. The three-dimensional flow, temperature and salinity fields of the North Atlantic, including the Arctic Ocean, covering the time period 1992 to 2006 are simulated with the numerical ocean model CODE. The simulation reveals several new insights and previously unknown structures which help us to clarify open questions on the regional oceanography of Icelandic waters. These relate to the structure and geographical distribution of the coastal current, the primary forcing of the North Icelandic Irminger Current (NIIC) and the path of the Atlantic Water south-east of Iceland. The model's adaptively refined computational mesh has a maximum resolution of 1 km horizontal and 2.5 m vertical in Icelandic waters. CTD profiles from this region and the river discharge of 46 Icelandic watersheds, computed by the hydrological model WaSiM, are assimilated into the simulation. The model realistically reproduces the established elements of the circulation around Iceland. However, analysis of the simulated mean flow field also provides further insights. It suggests a distinct freshwater-induced coastal current that only exists along the south-west and west coasts, which is accompanied by a counter-directed undercurrent. The simulated transport of Atlantic Water over the Icelandic shelf takes place in a symmetrical system of two currents, with the established NIIC over the north-western and northern shelf, and a hitherto unnamed current over the southern and southeastern shelf, which is simulated to be an upstream precursor of the Faroe Current (FC). Both currents are driven by barotropic pressure gradients induced by a sea level slope across the Greenland-Scotland Ridge. The recently discovered North Icelandic Jet (NIJ) also features in the model predictions and is found to be forced by the baroclinic pressure field of the Arctic Front, to originate east of the Kolbeinsey Ridge and to have a volume transport of around 1.5 Sv within northern Denmark Strait. The simulated multi-annual mean Atlantic Water transport of the NIIC increased by 85 % during 1992 to 2006, whereas the corresponding NIJ transport decreased by 27 %. Based on our model results we propose a new and further differentiated circulation scheme of Icelandic waters whose details may inspire future observational oceanography studies.

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Section: Icelandic River Runoffmentioning

confidence: 57%

The circulation of Icelandic waters – a modelling study

et al. 2013

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“…This procedure is called dynamical downscaling. Besides hydrological forecasts and climate impact studies, successful applications of LAM in hydrological modeling and cryospheric research using (re-)analysis data were reported by Kunstmann and Stadler (2005), Rögnvaldsson et al (2007a), Rögnvaldsson et al (2007b), Bernhardt et al (2010), Liu et al (2011), Marke et al (2011), Maussion et al (2011), Pavelsky et al (2011), Mölg et al (2012), and Marke et al (2014a). In addition, globally available data sets can also be considered valuable information for predictions in ungauged basins (Sivapalan et al, 2003) and ungauged climates (Merz et al, 2011).…”

Section: K Förster Et Al: Effect Of Meteorological Forcing and Snowmentioning

confidence: 99%

“…The previously cited studies include LAM applications of 1 month (Maussion et al, 2011), 3 months (Liu et al, 2011), 9 months (Pavelsky et al, 2011), and 1 year (Kunstmann and Stadler, 2005), respectively. Only Rögnvaldsson et al (2007b) consider 16 years (using a coarser grid of 8 km × 8 km), and the simulations of Mölg et al (2012) cover 3 years. In this study, two winter seasons with different meteorological conditions were selected for further investigation.…”

Section: Selected Winter Seasonsmentioning

confidence: 99%

Effect of meteorological forcing and snow model complexity on hydrological simulations in the Sieber catchment (Harz Mountains, Germany)

Förster

Meon

Marke

et al. 2014

Hydrol. Earth Syst. Sci.

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Abstract. Detailed physically based snow models using energy balance approaches are spatially and temporally transferable and hence regarded as particularly suited for scenario applications including changing climate or land use. However, these snow models place high demands on meteorological input data at the model scale. Besides precipitation and temperature, time series of humidity, wind speed, and radiation have to be provided. In many catchments these time series are rarely available or provided by a few meteorological stations only. This study analyzes the effect of improved meteorological input on the results of four snow models with different complexity for the Sieber catchment (44.4 km 2 ) in the Harz Mountains, Germany. The Weather Research and Forecast model (WRF) is applied to derive spatial and temporal fields of meteorological surface variables at hourly temporal resolution for a regular grid of 1.1 km × 1.1 km. All snow models are evaluated at the point and the catchment scale. For catchment-scale simulations, all snow models were integrated into the hydrological modeling system PANTA RHEI. The model results achieved with a simple temperature-index model using observed precipitation and temperature time series as input are compared to those achieved with WRF input. Due to a mismatch between modeled and observed precipitation, the observed melt runoff as provided by a snow lysimeter and the observed streamflow are better reproduced by application of observed meteorological input data. In total, precipitation is simulated statistically reasonably at the seasonal scale but some single precipitation events are not captured by the WRF data set. Regarding the model efficiencies achieved for all simulations using WRF data, energy balance approaches generally perform similarly compared to the temperature-index approach and partially outperform the latter.

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“…The watershed model WASIM was, therefore, run with meteorological input data from the MM5 model. Studies focusing on one-way coupling between atmospheric models and the WASIM watershed model in alpine landscapes have been reported earlier by Jasper et al (2002), Jasper & Kaufmann (2003) and by Kunstmann & Stadler (2005) as discussed by Rögnvaldsson et al (2007).…”

Section: Methodsmentioning

confidence: 99%

“…The model uses as initial and boundary data, the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA40 reanalysis (Kållberg et al, 2004) and calculates the weather in Iceland on a six-hourly time step (Rögnvaldsson et al, 2007). The precipitation from MM5 in Iceland has been compared to hydrological and glaciological data in Iceland; the WASIM model was set up for a few watersheds in Iceland using the MM5 data as an input to the watershed model (Rögnvaldsson et al, 2007). This study showed that MM5 data represent observed data over Iceland well.…”

Section: Methodsmentioning

confidence: 99%

A runoff map based on numerically simulated precipitation and a projection of future runoff in Iceland / Une carte d'écoulement basée sur la précipitation numériquement simulée et un scénario du futur écoulement en Islande

Jonsdottir

2008

Hydrological Sciences Journal

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Numerical simulations of precipitation in the complex terrain of Iceland Comparison with glaciological and hydrological data

Cited by 24 publications

References 0 publications

The circulation of Icelandic waters – a modelling study

The circulation of Icelandic waters – a modelling study

Effect of meteorological forcing and snow model complexity on hydrological simulations in the Sieber catchment (Harz Mountains, Germany)

A runoff map based on numerically simulated precipitation and a projection of future runoff in Iceland / Une carte d'écoulement basée sur la précipitation numériquement simulée et un scénario du futur écoulement en Islande

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