Tobias Günther

Gallery

In the following, several visualizations are shown that depict multiple scales of atmospheric flow fields and the Lagrangian patterns therein at highest quality. The visualizations appeared in Physical Review Fluids and were computed with our in-house renderer, described in Computer Graphics Forum. The simulations were computed with state-of-the-art simulation models for each atmospheric scale. For the visualizations, we used an unbiased and consistent Monte Carlo approach to avoid discretization of the finite-time Lyapunov exponent fields.

The following images are licensed under a Creative Commons Attribution 4.0 International License.

The 10.000 km Scale (global scale)

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This visualization shows a reanalysis simulation of the Northern hemisphere (data from the European Centre for Medium-Range Weather Forecasts), including the North American land surface, the North Atlantic Ocean and the European land mass. Here, the atmospheric flows are shown on a large scale. A close-up is shown on the right.
Licensed under CC-BY 4.0.

The 1.000 km Scale (synoptic scale)

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The COSMO-DE reanalysis simulation displays the air flow over central Europe. The model is currently in operational use by the German Weather Service (DWD). At the synoptic scale, the flow patterns are strongly influenced by global-scale features, the land-sea interaction, and orography.
Licensed under CC-BY 4.0.

The 100 km Scale (mesoscale)

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At the mesoscale, a semi-idealized large eddy simulation (LES) is shown for the area around Jülich, Germany, with a spatial resolution of 50m. The simulation was provided by Heinze et al. (2017) and uses boundary forcing from the COSMO-DE model.
Licensed under CC-BY 4.0.

The 10 km Scale

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The smallest scale displays a cloud-topped boundary layer simulation, created using the UCLA-LES model of Stevens et al. (2017). The simulation contains a cloud resolving domain with 25m spatial resolution under idealized conditions: It uses double-periodic boundary conditions and homogeneous surface forcing, while large-scale information is taken from the COSMO-DE model.
Licensed under CC-BY 4.0.

Three-dimensional Air Flow over Germany

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This visualization shows the finite-time Lyapunov exponent (FTLE) field over Germany. The underlying simulation was computed within the HD(CP)² project and the data was made available for the IEEE Scientific Visualization Contest 2017. Our submission to the contest can be found here. The FTLE field is an indicator for hyperbolic Lagrangian coherent structures, which act as transport barriers in vector fields. In this visualization, altitude is reversed (ground is at the top) and North is right. The visualization shows the turbulent movement near the ground and updraft columns towards higher altitude. The FTLE layer at high altitudes (bottom) is the tropopause, which is the boundary between troposphere and stratosphere.
Licensed under CC-BY 4.0.