Last updated: 23 Feb 2021
The Cosmo model used to be the operational and research & development softare of the Cosmo consortium until 2022, when Icon became the new recommended and supported one. This page gives a short account of the Cosmo-model operational use until then.
The first operational application of the COSMO-Model has been at DWD, where the model became operational on 1 December 1999. By that time it was still called LM, for Local Model. This first application was on a domain covering Middle Europe with a size of 325x325x32 grid points and a resolution of 0.0625 degree (about 7 km). This resolution is nowadays used by all partners of the Consortium for Small-Scale Modelling, except for DWD and MeteoSwiss. At DWD this application has been replaced by a nest of the global model ICON (called ICON-EU) in December 2016. MeteoSwiss switched to a full ensemble prediction system at higher resolutions in 2020.
In 2003 work started for developing and implementing a version of the COSMO-Model which is capable of running with very high resolutions reaching to the convection resolving scale of 1-3 km. The main work for that was the development of the Runge-Kutta dynamical core. The boundary conditions for these high-resolution runs are derived from forecasts of the coarser grid COSMO applications. Since April 2007, the COSMO-DE has been running at DWD with a resolution of 2.8 km. Other centers implemented applications with similar resolutions in the following years.
The next step in the further development of NWP applications has been the introduction of convection permitting ensemble systems to represent uncertainties in the forecast process. Based on the very-high resolution application, DWD developed its COSMO-DE-EPS, which runs operationally since May 2012.
Even before convection permitting ensembles were developed, ARPAE-SIMC installed the COSMO-LEPS (Limited Area Ensemble Prediction System) based on the COSMO-Model with 7 km resolution and ECMWF ensemble forecasts at the ECMWF computing centre. 16 operational model runs are performed (7 km grid spacing, 40 levels forecast range of 132 hours) starting at 12 UTC on initial and boundary conditions from 16 representative members of an ECMWF-EPS superensemble.
From 2010 on, several national weather services, which were using a former hydrostatic model HRM from DWD, migrated to the COSMO-Model. They can use the COSMO-Model for a yearly license fee of 20.000€. For countries which belong to the lower-middle-income economies in the World Bank list, the license fee is waived.
Boundary conditions for operational runs with moderate resolutions were derived from the forecasts of the global. IFS data from ECMWF could be used for boundary conditions. The forecasts from the moderate resolution applications can then be used to derive boundary conditions for higher resolution applications.
Also initial conditions could be derived from interpolated global analyses. When doing this it is possible to smooth the initial fields using the digital filtering scheme of Lynch et al. (1997).
A better choice for producing initial conditions for the COSMO-Model was to run a data assimilation system. At DWD a comprehensive assimilation system for the model has been installed, comprising the analysis for atmospheric fields, a sea surface temperature (SST) analysis and a snow depth analysis. For the 7 km application COSMO-EU also a soil moisture analysis according to Hess (2001) had been implemented. But this is not used for the higher resolution application COSMO-DE.
From the beginning of the COSMO-Model the assimilation of the atmospheric fields has been done by the Nudging technique. But since several years an ensemble based approach has been developed in the COSMO Priority Project KENDA (km based ensemble data assimilation). And since April 2017 DWD uses the KENDA based assimilation system.
The following table1, gives a brief overview on the configurations and the major specifications of the operational coarse grid systems in the COSMO centres. Through the links in the headings you can get a more detailed description of the different configurations including a detailed NAMELIST setting of the applications.
Please note that DWD and MeteoSwiss do not run a 7 km application any more.
Table2 again gives a brief overview on the major specifications of the very high resolution setups.
In Table 3 the major specifications of the ensemble systems are provided. Here are listed the Perturbed Parameters (pdf) with their values.
ARPAE−SIMC | HNMS | IMWM-NRI | NMA | Roshydromet | ITAF-Met | LEPS | |
---|---|---|---|---|---|---|---|
Domain Size (grid points) |
1083 x 559 | 1001 x 601 | 415 x 460 | 201 x 177 | 2000 x 1000 | 1083 x 559 | 511 x 415 |
Hor. Grid Spacing (degree/km) |
0.045 / 5 | 0.04 / 4 | 0.0625 / 7 | 0.0625 / 7 | 0.06 / 6.6 | 0.045 / 5 | 0.0625 / 7 |
Number of Layers | 45 | 80 | 40 | 40 | 40 | 45 | 40 |
Time Step (sec) | 45 | 30 | 60 | 66 | 40 | 45 | 66 |
Forecast Range (h) | 72 | 72 | 84 | 78 | 120,78, 120,78 | 72 | 132 |
Initial Time of Model Runs (UTC) | 00, 12 | 00, 12 | 00, 06, 12, 18 | 00, 06, 12, 18 | 00, 06, 12, 18 | 00, 06, 12, 18 | 00, 12 |
Lateral Boundary Conditions | IFS | IFS | ICON | ICON | ICON | IFS | IFS-ENS members |
LBC Update Frequency (h) | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
Initial State | CNMCA-LETKF | IFS | DAC/ICON | ICON | ICON | CNMCA-LETKF | IFS-ENS members |
External Analysis | SST, SNOW COVER MASK | None | None | SYNOP | None | SST, SNOW COVER MASK | soil-fields from ICON-EU |
Cosmo Version | 5.05 | 5.04e | 5.01 | 5.03 | 5.05 | 5.06 | 5.03 |
Hardware | Lenovo Broadwell Intel Cluster | Cray XC30 | Intel&HP based cluster | IBMcluster | Cray XC40-LC | Hybrid CPU/GPU cluster (CPU Intel, GPU NVIDIA) |
Cray XC (at ECMWF) |
No. of Processors used | 704 (22 nodes) | 1260 (35 nodes) | 140 | 56(of 112) | 1946 (of 35136) | 576 (24 nodes) | 720 tasks (on 20 nodes) |
DWD | IMWM-NRI | ITAF-Met | NMA | Roshydromet | IMS | ARPAE−SIMC | |
---|---|---|---|---|---|---|---|
Domain Size (grid points) |
651 x 716 | 380 x 405 | 576 x 701 | 361 x 291 | 1200 x 1400 | 561 x 401 | 576 x 701 |
Hor. Grid Spacing (degree/km) | 0.02 / 2.2 | 0.025 / 2.8 | 0.02 / 2.2 | 0.025 / 2.8 | 0.02 / 2.2 | 0.025 / 2.8 | 0.02 / 2.2 |
Number of Layers | 65 | 50 | 65 | 50 | 50 | 50 | 65 |
Time Step (sec) | 20 | 20 | 20 | 25 | 20 | 20,25 | 20 |
Forecast Range (h) | 27 | 48 | 30, 48 | 48 | 24h | 48 | |
Initial Time of Model Runs (UTC) |
00, 03, 06, 09, 12, 15, 18, 21 |
00, 06, 12, 18 | 00, 06, 12, 18 | 00, 06, 12, 18 | 00, 06, 12, 18 | 00, 12 hourly when rainy |
00, 03, 06, 09, 12, 15, 18, 21 UTC |
Lateral Boundary Conditions | ICON-EU | COSMO-PL7 | COSMO-ME | COSMO-Ro2 | COSMO-Ru6ENA | IFS | COSMO-5km |
LBC Update Frequency (h) | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
Initial State | KENDA + LHN | COSMO-PL7 | KENDA-LETKF | SYNOP/Radar | COSMO-Ru6ENA+ +Nudging+LHN | FS+Nudging+LHN | KENDA-LETKF |
External Analysis | SST, Snow Depth | None | SST | None | None | SST | SST |
Cosmo Version | 5.05b_1 | 5.01 | 5.06 | 4.18 | 5.05 | 5.05 | 5.05 |
Hardware | Cray XC40 | Intel&HP based cluster | Hybrid CPU/GPU cluster (CPU Intel, GPU NVIDIA) |
IBM cluster | Cray XC40-LC | SGI Altix | Lenovo Broadwell Intel Cluster |
No. of Cores used | 43x54+6 = 2328 (of 29952) | 160 | 576 (on 24 nodes) | 90 (of 144) | 2880 (of 35136) | 576 (of 1408) | 256 (8 nodes) |
ICON-D2-EPS (DWD) |
COSMO-1E (MeteoSwiss) | COSMO-2E (MeteoSwiss) |
TLE-MVE (IMWM-NRI) |
COSMO-2I-EPS (Arpae-SIMC, pre-ope) |
COSMO-ME-EPS (ITAF-Met) |
COSMO-IT-EPS (ITAF-Met) |
COSMO-LEPS (Arpae-SIMC) | |
---|---|---|---|---|---|---|---|---|
Domain Size (grid points) |
R19B07 542040 cells |
1170x786 | 582x390 | 380x405 | 576x701 | 779x401 | 576x701 | 511x415 |
Number of members | 20 | 11 | 21 | 21 | 20 | 40 | 20 | 20 |
Hor. Grid Spacing (degree/km) | ~2.1 km | 0.01/1.1 | 0.02/2.2 | 0.025/2.8 | 0.02/2.2 | 0.0625/7 | 0.02/2.2 | 0.0625/7 |
Number of Layers | 65 | 80 | 60 | 50 | 65 | 45 | 65 | 40 |
Time Step (s) | 20 | 10 | 20 | 20 | 18 | 60 | 20 | 66 |
Forecast Range (h) | 27 (45 for 03 UTC run) | 33 (45 for 03 UTC run) | 120 | 48 | 51 | 72 | 48 | 132 |
Initial Time of Model Runs (UTC) |
00, 03, 06, 09, 12, 15, 18, 21 |
00, 03, 06, 09, 12, 15, 18, 21 |
00, 06, 12, 18 | 00, 06, 12, 18 | 21 | 00, 12 | 00, 12 | 00, 12 |
Lateral Boundary Conditions | ICON-EU-EPS | ECMWF HRES and ENS | ECMWF ENS | COSMO-PL7 (Time-Lagged) | COSMO-ME-EPS | IFS-ENS | COSMO-ME-EPS | IFS-ENS (time-lagged + cluster analysis) |
LBC update freq (h) | 1 | 1 | 3 | 1 | 3 | 3 | 3 | 3 |
Initial state | KENDA (+LHN) | KENDA 1.1km (+LHN) | KENDA 1.1 km, upscaled to 2.2 km (+LHN) | COSMO-PL7 (Time-Lagged) | KENDA (+LHN) | CNMCA-LETKF | KENDA | IFS-ENS (time-lagged + cluster analysis) + soil from ICON-EU |
External analysis | SST, snow height | SST (ECMWF HRES and ENS), snow depth | SST (ECMWF ENS), snow depth | None | None | None | None | None |
Physics perturbation | Parameter perturbation (randomized draw from selection of predefined perturbed values) |
SPPT | SPPT | c_soil | None | SPPT | None | Parameter perturbation (randomized draw from selection of predefined perturbed values) |
COSMO version | - | 5.07+ (GPU/SP) | 5.07+ (GPU/SP) | 5.01 | 5.05 | 5.05b 5.0+ (GPU) |
5.0+ (GPU) | 5.03 in single precision |
hardware | Cray CS-Storm | Cray CS-Storm | Intel & HP based cluster | Lenovo Broadwell Intel cluster | ECMWF Cray HP |
HP | ECMWF Cray | |
No. of core used | 14+8 GPUs per member | 6+4 GPUs per member | 240 per member | 192 core per member | 432 every 4 members 24+4 GPUs per member |
24+8 GPUs per member | 720 |