Core documentation

Last updated: 29 Apr 2025

1. Non Cosmo-model-only documentation

Here is official documantation that applies both to Cosmo-model and its replacemnt Icon, or Icon-only

title brief notes date download
Icon tutorial Working with the ICON Model by F. Prill, D. Reinert, D. Rieger and G. Zängl Mar 2023 pdf
Boxtracking New scheme for the Seifert-Beheng 2-moment cloud microphysical scheme This document describes the new implementation of the explicit hydrometeor sedimentation in the Seifert-Beheng 2-moment bulk microphysical scheme. The work has been realized by U. Blahak (DWD). Feb 2020 pdf
changes for graupel and hail in the 2-moment microphysics (U. Blahak) Apr 2024 pdf
EMVORADO Efficient Modular VOlume scan RADar Operator The Efficient Modular VOLume RADar forward Operator EMVORADO computes synthetic radar volume scan observations of radial wind (m/s), radar reflectivity (dBZ) and the dual polarization parameters ZDR, RHOHV, KDP, PHIDP and LDR on the basis of the simulated prognostic atmospheric fields of NWP-models for a given set of radar stations.
the previous single-polarization version Jul 2020 pdf
the new single and dual polarization version Feb 2025 pdf

2. Cosmo-model (only) documentation

Part I: Dynamics and Numerics

This part of the documentation provides information on the theoretical and numerical formulation of the model covering both the basic thermodynamics and the particular numerical schemes to solve the model equations.

  • Get Documentation Part I (5.00), November 2013, with DOI (pdf, 1.6 Mb)
  • Get Documentation Part I (5.05), February 2018, with DOI (pdf, 1.8 Mb)
  • Get Documentation Part I (6.00), September 2021, with DOI (pdf, 1.8 Mb)

Part II: Physical Parameterization

This part of the documentation reviews shorly the basic subgrid-scale physical processes and describes in detail the corresponding parameterization schemes.

  • Get Documentation Part II (4.20), September 2011, (without DOI, but often cited in the past) (pdf, 3.9 Mb)
  • Get Documentation Part II (5.00), November 2013, with DOI (pdf, 3.6 Mb)
  • Get Documentation Part II (5.05), February 2018, with DOI (pdf, 3.8 Mb)
  • Get Documentation Part II (6.00), September 2021, with DOI (pdf, 3.8 Mb)

Part III: Data Assimilation

The data assimilation part of the documentation describes the full analysis system of the COSMO-package. It is made-up of four components:

  1. the nudging analysis scheme
  2. the sea-surface temperature analysis
  3. the snow depth analysis
  4. the soil moisture analysis

Part V: Preprocessing (int2lm)

For operational applications, COSMO is nested in the global models GME (until January 2015) and ICON (starting January 2015) of DWD. Initial and boundary conditions are provided by the pre-processing program INT2LM for analyses and forecasts of GME, ICON or the ECMWF global model IFS. A detailed description of how to work with GME, ICON or IFS data is provided.

  • Get Documentation Part V (2.00), November 2013, with DOI (pdf, 0.6 Mb)
  • Get Documentation Part V (2.05), February 2018, with DOI (pdf, 0.8 Mb)
  • Get Documentation Part V (2.08), February 2021, (pdf, 0.9Mb)
  • Get Documentation Part V (3.00), September 2021, with DOI (pdf, 0.9Mb)

Part VI: Model Output and Data Formats for I/O

This part of the documentation provides information about the output of the COSMO-Model. First, there are the output fields (in GRIB or NetCDF). Besides the prognostic variables several diagnostics are computed in the model and can be written (e.g. 2m-temperature, wind gusts, height of snow melt, etc.). Most atmospheric fields can also be interpolated to p- or z-levels. Another type of output are several ASCII output fields, that are also described. This guide also contains the description of the output from data assimilation (nudging).

In addition, the possible output formats GRIB (1/2) and NetCDF are described briefly.

  • Get Documentation Part VI (5.05), February 2018, with DOI (pdf, 1.0Mb)
  • Get Documentation Part VI (6.00), September 2021, with DOI (pdf, 1.0Mb)

Part VII: User's Guide

The user guide of COSMO provides information on code access as well as hardware and software requirements for executing the code. Short tutorials on how to install and run the model are included. The user guide contains a detailed description of all control parameters in the NAMELIST input file. These control parameters allow a flexible set-up of model runs for various applications.

Idealized Simulations

This document describes how to set up idealized simulations with COSMO. This mode is useful for researchers doing process studies, but also for model developers when testing new features. The possibilities range from simple 2D flow-over-idealized-hill simulations, 3D idealized convective cell experiments (e.g., Weisman-Klemp-type), LES-like studies with very high spatial resolution to more complex setups using realistic orography and land use.

For each 'component' of a model run (orography, other external parameters, initial (thermo)-dynamic profiles, surface fluxes, model boundary conditions, artificial convection triggers, etc.) there are different choosable options (like a kit with lots of toys), which can be more or less freely combined via extensive namelist parameters.

The documentation is in a draft stage, but you can already find a complete namelist parameter documentation, and the 'cookbook' (together with many exemplary model runscripts in subdirectory RUNSCRIPTS of the code distribution) should get you started.

Feedback File definition

The Feedback File Definition is a supplementary documentation which describes the format of the NetCDF feedobs or feedback file. This file is produced by the data assimilation part of the COSMO model and can be used for LETKF or verification purposes.

Other

Some other usefull documentation about the Cosmo-model: