Klaus Dethloff

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This report describes version 5(β) of the HIRHAM regional climate model. The report is in two parts. The first part discusses the structure and main features of the upgraded version of the model system, while the second part offers a short tutorial on how to install and run the code, e.g. on NEC SX6. Resumé Denne rapport beskriver version 5(β) af den(More)
Keywords: Finite elements Finite volumes Shallow water equations Triangular grid Spherical geometry Surface a b s t r a c t A global model of the atmosphere is presented governed by the shallow water equations and discretized by a Runge–Kutta discontinuous Galerkin method on an unstructured triangular grid. The shallow water equations on the sphere, a(More)
The parallel adaptive model PLASMA has been developed for modeling a barotropic atmosphere. This model adapts the computational grid at every time step according to a physical error indicator. Thus, compared to uniform grid experiments the number of grid points is reduced significantly. At the same time, the error increases only slightly, when comparing(More)
We investigate the formation of small scale filaments in a novel adaptive tracer transport model. The numerical model is based on a semi-Lagrangian advection scheme, and an adaptively and locally refined triangular mesh. The adaptive modelling approach allows very high local resolution, showing fine grained filamentation under the influence of background(More)
a r t i c l e i n f o Keywords: Arctic climate change air temperature permafrost regional climate model A regional climate model with high horizontal resolution (25 km) is used to downscale 20-year-long time slices of present-day (1980–1999) and future (2046–2065, 2080–2099) Arctic climate, as simulated by the ECHAM5/MPI-OM general circulation model under(More)
This paper discusses results of a simulation with the regional climate model HIRHAM for 1958-2001, driven by the ECMWF reanalysis (ERA40) data over the Arctic domain. The aim is to analyze the ability of the model to capture certain features of climate extremes derived from daily mean, maximum and minimum temperatures. For this purpose, a range of climate(More)
A global barotropic model of the atmosphere is presented governed by the shallow water equations and discretized by a Runge-Kutta discontinuous Galerkin method on an unstructured triangular grid. The shallow water equations on the sphere, a two-dimensional surface in R 3 , are locally represented in terms of spherical triangular coordinates, the appropriate(More)
During ice-free periods, the Northern Sea Route (NSR) could be an attractive shipping route. The decline in Arctic sea-ice extent, however, could be associated with an increase in the frequency of the causes of severe weather phenomena, and high wind-driven waves and the advection of sea ice could make ship navigation along the NSR difficult. Accurate(More)
The Arctic atmospheric boundary layer (AABL) in the central Arctic was characterized by dropsonde, lidar, ice thickness and airborne in situ measurements during 321 the international Polar Airborne Measurements and Arctic Regional Climate Model Simulation Project (PAMARCMiP) in April 2009. We discuss AABL observations in the lowermost 500 m above (A) open(More)