Assimilation of visible and near-infrared satellite images
High-resolution observations from instruments on geostationary satellites
provide a wealth of information about convective activity and are therefore
seen as a important type of observation for convective scale data assimilation
(DA). In particular the visible and near-infrared channels provide information
on the cloud distribution, cloud microphysical properties and cloud structure
with high temporal and spatial resolution. However, in operational DA systems
currently only clear sky thermal infrared and microwave radiance observations
are used, which mainly provide temperature and humidity
information. Sufficiently fast and accurate forward operators for visible and
near-infrared radiances are not yet available, because multiple scattering
makes radiative transfer at solar wavelengths complicated and computationally
Only recently a we developed MFASIS, a loop-up table based 1D radiative
transfer method that is orders of magnitude faster than conventional radiative
transfer solvers for the visible spectrum and similarly accurate. A
preliminary version of a forward operator based on this method, which
simulates synthetic MSG-SEVIRI images from COSMO-DE model output, has been
completed and implemented in the pre-operational km-scale Ensemble Data
Assimilation (KENDA) system of DWD. To improve the consistency and accuracy of
the operator we included computationally cheap methods to account for the
overlap of subgrid clouds and the most important 3D radiative transfer
MFASIS has also been used to evaluate large domain large eddy simulations
carried out using the ICON model in the framework of the HD(CP)2
project. Synthetic 0.6 and 0.8 micron MODIS images with 250m resolution were
computed from 3D model states with a grid resolution of about 150m. The high
resolution allowed us to determine the effective grid resolution from cloud
Former research topics
Tropical cyclones, singular Vectors, adaptive grid refinement in the framework of the METSTRÖM project,
high performance computing, visualization and computational steering at LRZ,
core collapse supernovae and extragalactic jets at the MPI for Astrophysics.
CosmoState is a grib_api-based Python module to read GRIB1 and GRIB2 files generated by COSMO (and possibly other NWP models).
Simple numerical schemes for PDEs
Interactive IPython notebook illustrating the properties of simple
numerical schemes for the linear advection equation and the
non-linear Burgers equation (there is also a non-interactive HTML version).
- 2013 -- now: PostDoc at the data assimilation branch of the Hans Ertel Centre for Weather Research located at LMU Munich.
- 2008 -- 2013: PostDoc at Karlsruhe Institute of Technology, working on tropical cyclones, singular vectors
- 2006 -- 2008: Scientific employee at Leibniz Supercomputing Center, Garching
- 2001 -- 2006: PhD project at Max-Planck Institute for Astrophysics, Garching
- 1993 -- 2000: Diploma in Physics, Technical University Munich
Efficient methods to account for cloud top inclination and cloud overlap in synthetic visible satellite images,
Metrics for the evaluation of warm convective cloud fields in a large eddy simulation with Meteosat images,
A fast radiative transfer method for the simulation of visible satellite imagery,
Journal of Quantitative Spectroscopy and Radiative Transfer, Vol. 175, p.54–67, may 2016.
[ link ]
Goal-oriented adaptivity for idealised tropical cyclones: A binary interaction scenario,
Meteorologische Zeitschrift, Vol. 24, No. 3, p.269–292 2015.
Simulation of tropical-cyclone-like vortices in shallow-water ICON-hex using goal-oriented r-adaptivity,
Theoretical and Computational Fluid Dynamics, Vol. 28, No. 1, p.107–128 2014.
Singular Vectors for Barotropic, Hurricane-Like Vortices in Horizontal Shear: Structure and Perturbation Growth Mechanisms,
Journal of the Atmospheric Sciences, Vol. 71, No. 3, p.1002–1020 2014.
Mesoscale cyclogenesis over the western north Pacific Ocean during TPARC,
Tellus Series a-Dynamic Meteorology and Oceanography, Vol. 65 2013.
The Resonant Interaction of a Tropical Cyclone and a Tropopause Front in a Barotropic Model. Part I: Zonally Oriented Front,
Journal of the Atmospheric Sciences, Vol. 68, No. 3, p.405–419 2011.
The Resonant Interaction of a Tropical Cyclone and a Tropopause Front in a Barotropic Model. Part II: Frontal Waves,
Journal of the Atmospheric Sciences, Vol. 68, No. 3, p.420–429, mar 2011.
[ link ]
Interactive Indoor Thermal Comfort Evaluation,
High Performance Computing in Science and Engineering, Garch/Munich 2007, p.421–430 2009.
Multidimensional supernova simulations with approximative neutrino transport - II. Convection and the advective-acoustic cycle in the supernova core,
Astronomy \& Astrophysics, Vol. 477, No. 3, p.931–952 2008.
Instability of a stalled accretion shock: Evidence for the advective-acoustic cycle,
Astrophysical Journal, Vol. 654, No. 2, p.1006–1021 2007.
Nucleosynthesis-relevant conditions in neutrino-driven supernova outflows - I. Spherically symmetric hydrodynamic simulations,
Astronomy \& Astrophysics, Vol. 467, No. 3, p.1227–1248 2007.
Multidimensional supernova simulations with approximative neutrino transport - I. Neutron star kicks and the anisotropy of neutrino-driven explosions in two spatial dimensions,
Astronomy \& Astrophysics, Vol. 457, No. 3, p.963–U101 2006.
Neutrino-driven convection versus advection in core-collapse supernovae,
Astrophysical Journal, Vol. 652, No. 2, p.1436–1450 2006.
Non-spherical core collapse supernovae - II. The late-time evolution of globally anisotropic neutrino-driven explosions and their implications for SN 1987 A,
Astronomy \& Astrophysics, Vol. 453, No. 2, p.661–U17 2006.
Neutrino-driven supernovae: An accretion instability in a nuclear physics controlled environment,
Nuclear Physics a, Vol. 758, p.19C–26C 2005.
Supernova Asymmetries and pulsar kicks - Views on controversial issues,
in: Fate of the Most Massive Stars, Proceedings, Vol. 332, p.363–373 2005.
Neutrino signatures of supernova forward and reverse shock propagation,
Journal of Cosmology and Astroparticle Physics, No. 9 2004.
Pulsar recoil by large-scale anisotropies in supernova explosions,
Physical Review Letters, Vol. 92, No. 1 2004.
Does the plasma composition affect the long-term evolution of relativistic jets?,
Monthly Notices of the Royal Astronomical Society, Vol. 331, No. 3, p.615–634 2002.
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