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PALM group (Head: Siegfried Raasch)


PALM group

Our main research tool is the parallelized Large-Eddy Simulation (LES) Model PALM, the original version of which was developed from 1997-1999 at our institute. This model is optimized for use on massively parallel computers, and it is therefore very well suited for simulations with an extremely large number of grid points. The current supercomputer of the North German Supercomputing Center "Norddeutscher Verbund für Hoch- und Höchstleistungsrechnen" (HLRN), an SGI-ICE machine with 12000 cores, allows calculations with up to 40963 grid points.

Further information on PALM is available using the PALM quick links below.

Our research focusses on the analysis of micro- and mesoscale turbulent boundary layers. Other key parts of our work include numerical improvements of PALM, in particular parallelized numerical schemes, and the development of software systems that are able to effectively visualize the extremely large data amount that is typical of parallelized models.

The photo shows our research group (as of August 2009) in front of some of the nodes of the new HLRN-II SGI Altix computer.
From left to right: Naoki Ikegaya, Gahyun Goh, Carolin Weinreis, Jungwha Lee, Jens Kampmeyer, Theres Franke (Front)  Siegfried Raasch (Head), Rieke Heinze, Björn Witha, Björn Maronga, Marcus Letzel, Micha Gryschka, Yvonne Breitenbach (Back)
(Photo: G. Gaus)


Contents of this page:

PALM quick links:

Contact details


Leibniz University of Hannover
Institute of Meteorology and Climatology
PALM group
Herrenhäuser Str. 2
30419 Hannover







Franke, Theres



 Fricke, Jens


Gryschka, Micha



Heinze, Rieke

4413 F225

Kampmeyer, Jens

 Kanani, Farah

3232 F233
 Knigge, Christoph

2680 F221

Maronga, Björn

2680 F221

Raasch, Siegfried (Head)



 Sühring, Matthias

4413 F225
 Voß, Linda

3232 F233

Weinreis, Carolin



Witha, Björn





*Phone number +49 511 762-Ext.

Former members and visitors (function)


 Breitenbach, Yvonne (Diploma student)

Hamann, Ulrich (Diploma student)

Harbusch, Guido (Diploma student)

Herold, Marcus (Diploma student)

 Ikegaya, Naoki (visiting student)

Inagaki, Dr. Atsushi (visiting student)

Jang, Mi-jin (visiting student)

Jansen, Dr. Heiko (researcher)

Kang, In-Soo (visiting student)

Krane, Martina (Diploma student)

 Letzel, Dr. Marcus (researcher)

 Lin Cai Feng, Sarah (visiting student)

Lotz, Johannes (visiting student)

Noh, Prof. Dr. Yign (visiting researcher)

Rautenhaus, Marc (student)

Rottmann, Tobias (student)

Schröter, Dr. Michael (researcher)

Steinfeld, Dr. Gerald (researcher)

Uhlenbrock, Dr. Jörg (researcher)

Weinbrecht, Dr. Sonja (researcher)

Zhang, Jin (visiting student)

Current research projects
short description, in chronological order sorted by starting date:

Short description of future research topics:

Previous research projects
short summary, in chronological order sorted by starting date


Reviewed publications (under participation) of the PALM group since 1997 in chronological order:

Foken, T., M. Mauder, C. Liebethal, F. Wimmer, F. Beyrich, J.-P. Leps, S. Raasch, H. A. R. DeBruin, W. M. L. Meijninger and J. Bange, 2010: Energy balance closure for the LITFASS-2003 experiment, Theor. Appl. Clim.101, 149-160, doi:10.1007/s00704-009-0216-8.

Noh, Y.,  G. Goh,  S. Raasch and M. Gryschka, 2009: Formation of a diurnal thermocline in the ocean mixed layer simulated by LES, J. Phys. Oceanogr., 39, 1244-1257.

Markkanen, T., G. Steinfeld, N. Kljun, S. Raasch and T. Foken, 2009: Comparison of conventional Lagrangian stochastic footprint models against LES driven footprint estimates, Atmos. Chem. Phys., 9, 5575-5586,

Gryschka, M., C. Drüe, D. Etling and S. Raasch, 2008: On the influence of sea-ice inhomogeneities onto roll convection in cold-air outbreaks, Geophys. Res. Lett., 35, L23804, doi:10.1029/2008GL035845.

Gryschka, M.,  B. Witha and D. Etling, 2008: Scale Analysis of Convective Clouds,  Meteorol. Z., 17, 785-791.

Steinfeld, G., S. Raasch and T. Markkanen, 2008: Footprints in homogeneously and heterogeneously driven boundary layers derived from a Lagrangian stochastic particle model embedded into large-eddy simulation, Boundary-Layer Meteorol., 129, 225-248.

Letzel, M.O., M. Krane and S. Raasch, 2008: High resolution urban large-eddy simulation studies from street canyon to neighbourhood scale, Atmos. Env., 42, 8770-8784, doi:10.1016/j.atmosenv.2008.08.001.

Lüpkes C., V. Gryanik, B. Witha, M. Gryschka, S. Raasch and T. Gollnik, 2008: Modeling convection over arctic leads with LES and a non-eddy-resolving microscale model, J. Geophys. Res., 113, C09028, doi:10.1029/2007JC004099

Letzel, M. O., G. Gaus, S. Raasch, N. Jensen and M. Kanda, 2008: Turbulent flow around high-rise office buildings in downtown Tokyo. Dynamic Visualization in Science

Steinfeld, G., M. O. Letzel, S. Raasch, M. Kanda and A. Inagaki, 2007: Spatial representativeness of single tower measurements and the imbalance problem with EC fluxes - results of an LES study, Boundary-Layer Meteorol., 123, 77-98. doi:10.1007/s10546-006-9133-x

Bange, J., P. Zittel, T. Spieß, J. Uhlenbrock and F. Beyrich, 2006: A New Method for the Determination of Area-Averaged Turbulent Surface Fluxes from Low-Level Flights Using Inverse Models. Boundary-Layer Meteorol., 119, 527-561.

Noh, Y., Kang, I.S., Herold, M. and S. Raasch, 2006: Large Eddy Simulation of Particle Settling in the Ocean Mixed Layer. Phys. of Fluids, 18, 085109.

Beare, R.J, M.A.J. Cortes, J. Cuxart, I. Esau, C. Golaz, A.A.M. Holtslag, M. Khairoutdinov, B. Kosovic, D. Lewellen, T. Lund, J. Lundquist, A. Mccabe, M.K. Macvean, A. Moene, Y. Noh, G. Poulos, S. Raasch and P. Sullivan, 2006: An Intercomparison of Large-Eddy Simulations of the Stable Boundary Layer. Boundary-Layer Meteorol., 118, 247-272.

Mengelkamp, H.-T., F. Beyrich, G. Heinemann, F. Ament, J. Bange, F. Berger, J. Bösenberg, T. Foken, B. Hennemuth, C. Heret, S. Huneke, K.-P. Johnsen, M. Kerschgens, W. Kohsiek, J.-P. Leps, C. Liebethal, H. Lohse, M. Mauder, W. Meijninger, S. Raasch, C. Simmer, T. Spieß, A. Tittebrand, J. Uhlenbrock and P. Zittel, 2006: Evaporation Over a Heterogeneous Land Surface: The EVA-GRIPS Project. Bull. Amer. Meteor., Soc., 87, 775-786.

Inagaki, A., M.O. Letzel, S. Raasch and M. Kanda, 2006: Impact of surface heterogeneity on energy imbalance: a study using LES. J. Meteor. Soc. Japan, 84, 187-198. doi:10.2151/jmsj.84.187

Gryanik, V., J. Hartmann, S. Raasch and M. Schröter, 2005: A Refinement of the Millionshchikov Quasi-Normality Hypothesis for Convective Boundary Layer Turbulence. J. Atmos. Sci., 62, 2632-2638.

Gryschka, M. and S. Raasch, 2005: Roll Convection During a Cold Air Outbreak: A Large Eddy Simulation with Stationary Model Domain. Geophys. Res. Lett., 32, L14805, doi:10.1029/2005GL022872.

Raabe, A., K. Arnold, A. Ziemann, F. Beyrich, J.-P. Leps, J. Bange, P. Zittel, T. Spiess, T. Foken, M. Göckede, M. Schröter and S. Raasch, 2005: STINHO - Structure of Turbulent Transport Under Inhomogeneous Surface Conditions - Part 1: The Micro-a Scale Field Experiment. Meteorol. Z., 14, 315-327.

Schröter, M., S. Raasch and H. Jansen, 2005: New Results on the Cell Broadening Problem during Cold Air Outbreaks from High Resolution Large-Eddy Simulations. J. Atmos. Sci., 62, 2023-2032.

Kanda, M., A. Inagaki, M.O. Letzel, S. Raasch and T. Watanabe, 2004: LES Study of the Energy Imbalance Problem with Eddy Covariance Fluxes. Boundary-Layer Meteorol., 110, 381-404. doi:10.1023/B:BOUN.0000007225.45548.7a

Kim, H.-J., Y. Noh and S. Raasch, 2004: Interaction between wind and temperature fields under the heterogeneous heat flux in the planetary boundary layer. Boundary-Layer Meteorol., 111, 225-246.

Min, H.S. and Y. Noh, 2004: Influence of the Surface Heating on Langmuir Circulation. J. Phys. Oceanogr., 34, 2630-2641.

Noh, Y., H.S. Min and S. Raasch, 2004: Large Eddy Simulation of the Ocean Mixed Layer: the Effects of Wave Breaking and Langmuir Circulation. J. Phys. Oceanogr., 34, 720-735.

Weinbrecht, S., S. Raasch, A. Ziemann, K. Arnold and A. Raabe, 2004: Comparison of Large-Eddy Simulation data with spatially averaged measurements obtained by Acoustic Tomography - presuppositions and first results. Boundary-Layer Meteorol., 111, 441-465.

Etling, D. and S. Weinbrecht, 2004: Organized structures in the atmospheric boundary layer. In: Shallow Flows (G. Jirka, W. Uijttewal, Eds.), Balkema, London, 157-162.

Inagaki, A., M. Kanda, M.O. Letzel and S. Raasch, 2003: LES Study of the Energy Imbalance Problem for Heterogeneous Surface (in Japanese). Annual J. Hydraulic Eng., JSCE, 47, 37-42.

Letzel, M.O. and S. Raasch, 2003: Large-Eddy Simulation of Thermally Induced Oscillations in the Convective Boundary Layer. J. Atmos. Sci., 60, 2328-2341. doi:10.1175/1520-0469(2003)060<2328:LESOTI>2.0.CO;2

Noh, Y., W.-G. Cheon, S.-Y. Hong and S. Raasch, 2003: Improvement of the K-Profile Model for the Planetary Boundary Layer based on Large Eddy Simulation Data. Boundary-Layer Meteorol., 107, 401-427.

Noh, Y., W.-G. Cheon and S. Raasch, 2003: The Role of Preconditioning in the Evolution of Open-Ocean Deep Convection. J. Phys. Oceanogr., 33, 1145-1166.  (selected among "Papers of note" in the Bull. Amer. Meteor. Soc., 84, 574-575, in May 2003)

Etling, D., G. Harbusch and B. Brümmer, 2002: Large-Eddy Simulation of an off-ice airflow during BASIS. Boreal Env. Res., 7, 225-228.

Kanda, M., M.O. Letzel, A. Inagaki and S. Raasch, 2002: Investigation on Spatial Representativeness of Point Measurements - Implication for Imbalance Problem (in Japanese). Annual J. Hydraulic Eng., JSCE, 46, 97-102.  (awarded the Best Paper Price of the 46th "Suiko" Conference (Water Civil Engineering) in Nagoya, Japan, by the Japan Society of Civil Engineers on 12 March 2002)

Kanda, M., T. Watanabe, M.O. Letzel and S. Raasch, 2002: LES Study on the Energy Imbalance Problem with Eddy Covariance Fluxes. I. Analysis for Convective Boundary Layers (in Japanese).  J. Japan Soc. Hydro. Water Res., 15, 243-252.

Letzel, M.O. and S. Raasch, 2002: Large-Eddy Simulation of Thermally Induced Oscillations in the Convective Boundary Layer. Annual J. Hydraulic Eng., JSCE, 46, 67-72.

Olbrich, S., H. Pralle and S. Raasch, 2001: Using streaming and parallelization techniques for 3D visualization in a high-performance computing and networking environment. Lecture Notes in Computer Science2110, 231-240.

Raasch, S. and G. Harbusch, 2001: An Analysis of Secondary Circulations and their Effects Caused by Small-Scale Surface Inhomogeneities Using Large-Eddy Simulation. Boundary-Layer Meteorol., 101, 31-59.

Raasch, S. and M. Schröter, 2001: A Large-Eddy Simulation Model performing on Massively Parallel Computers. Meteorol. Z., 10, 363-372.

Weinbrecht, S. and S. Raasch, 2001: High Resolution Simulations of the Turbulent Flow in the Vicinity of an Arctic Lead. J. Geophys. Res., 106 C11, 27035-27046.

Schröter, M., J. Bange and S. Raasch, 2000: Simulated Airborne Flux Measurements in a LES Generated Convective Boundary Layer. Boundary-Layer Meteorol., 95, 437-456.

Raasch, S. and D. Etling, 1998: Modeling Deep Ocean Convection: Large Eddy Simulation in Comparison with Laboratory Experiments. J. Phys. Oceanogr., 28, 1786-1802.

Hartmann, J., C. Kottmeier and S. Raasch, 1997: Roll Vortices and Boundary-Layer Development During a Cold Air Outbreak. Boundary-Layer Meteorol., 84, 45-65.

Recent work submitted for publication:

Letzel, M.O., C. Helmke, E. Ng, X. An and S. Raasch, 2010: LES study on pedestrian level ventilation in Hong Kong. Building and Environment, submitted.

Noh, Y., G. Goh and S. Raasch, 2010: Examination of the Mixed Layer Deepening Process during Convection Using LES. J. Phys. Oceanogr., accepted.

Markkanen, T., G. Steinfeld, N. Kljun, S. Raasch and T. Foken, 2010: A numerical case study on footprint model performance under inhomogeneous flow conditions. Meteorol. Z., accepted.

Selected conference abstracts:

Last update: 26 May, 2010     Please email suggestions or comments concerning this page to Siegfried Raasch (see members).