Tools and datasets

English

In PANDOWAE several partners work with given tools or datasets. By the use of operational models and datasets there is an intensive collaboration with operational centres.

 The sharing of tools or datasets has proven to be of major benefit for the individual PIs working in PANDOWAE. Some partners have worked with the same models, others have exchanged diagnostic packages or carried out model runs / diagnostic calculations for the weather systems studied by another partner. The collaboration with operational centres has been furthered by the use of operational models and datasets:

 

COSMO: The Consortium for Small-Scale Modelling (COSMO) model is a non-hydrostatic limited area model based on the Lokal-Modell (LM) (Steppeler et al. 2003) originally developed at the DWD and run operationally at DWD with 7 km horizontal resolution (COSMO-EU, formerly LME) and 2.8 km horizontal resolution (COSMO-DE, formerly LMK). A number of other European weather services have contributed to the development of the COSMO system. The COSMO model is installed at several partner institutes (Karlsruhe, Mainz, DLR) and has been used for several years with horizontal resolutions ranging from 40 km to 1 km.

COSMO-LEPS: In the COSMO-LEPS system (Molteni et al. 2001; Tibaldi et al. 2003) the COSMO model is nested in 10-15 members of the ECMWF ensemble prediction system (EPS) that are selected using a clustering algorithm.

GME: The GME (Global Model Europe) is the operational global weather forecast model of the German Weather Service (Majewski et al. 2002). It is hydrostatic and based on an icosahedral grid.

Different products of the ECMWF:

ECMWF operational analyses: The current model version T799L91 and the 4d-var data assimilation scheme provide global analyses every 3 hours with a horizontal resolution of approximately 25 km.

ECMWF IFS Deterministic forecasts: The same model version is used for twice daily 10-day global forecasts, started at 00 and 12 UTC.

ECMWF IFS EPS: the operational ECMWF ensemble prediction system is run at a T399L62 with a control forecast and 51 perturbed members. The initial perturbations are calculated using singular vectors (Molteni et al. 1996; Leutbecher et al. 2007) and a stochastic physics scheme is included (Buizza et al. 1999).

ECMWF IFS Data assimilation system: The ECMWF system used in Phase 1 has a 12 hour window four-dimensional variational (4D-Var) data assimilation system, where the full model resolution (T799) is used for comparing observation and model equivalents and a reduced resolution (T255/T95) for their minimization. For research applications, the ECMWF system can be applied to reproduce the analysis of any given date with a large number of options: incorporating additional observations, ignoring particular observation types or observations in particular regions, reducing the resolution and many others changes.

ECMWF Data Targeting System: was customised at ECMWF for T-PARC and provided the framework by which sensitive area calculations could be requested during T-PARC and the results from 6 different calculations displayed in a common graphical format.

ECMWF ERA40 und ERAinterim: The ERA40 data set was produced with ECMWF model version T159L60 (corresponding to a horizontal resolution of about 100 km) and the 3d-Var data assimilation technique for the time period 1958-2002. It provides a reasonably consistent meteorological data set for this extended period, allowing climatological investigations of various weather phenomena. ERA-interim is the newest reanalysis data set provided by ECMWF, covering 1989 to the present. ERA-interim is available at a slightly higher spatial resolution (T255), a new humidity analysis and a 4D-Var-assimilation scheme were used. These improvements are said to be especially beneficial for the tropical areas.

TIGGE: Ten operational Numerical Weather Prediction centres have agreed to deliver a selection of data from global ensemble forecasts in near real time to the THORPEX Interactive Grand Global Ensemble data base. CMA, ECMWF and NCAR have agreed to become Archive and Distribution centres (Bougeault, 2006). TIGGE data will be available for research purposes with a delay of 48 h after the initial time of the forecast.

ECHAM: The GCM ECHAM is a global climate model which was developed at the Max-Planck-Institut für Meteorologie in Hamburg and Universität Hamburg based on the ECMWF forecast model.

MM5: The fifth-generation Pennsylvania State University - National Center for Atmospheric Research (PSU-NCAR) Mesoscale Model. This is a non hydrostatic mesoscale circulation model involving an Arakawa-Lamb B-staggered grid on sigma surfaces.

Piecewise PV inversion: Potential vorticity inversion code (Davis and Emanuel 1991) has been provided by Dr. Christopher Davis. This code has been modified so it can be used to diagnose COSMO model output as well as removing the balanced fields associated with a PV anomaly from the initial conditions.

EOF/Cluster analysis: This methodology uses a combination of an empirical orthogonal function analysis and a fuzzy clustering applied to the principal components (Harr et al. 2007). Thus ensemble members with similar contributions to the variability patterns are identified through the EOF analysis.

LAGRANTO: This Lagrangian analysis tool (Wernli and Davies 1997) is used to calculate trajectories with wind fields from ECMWF analyses and COSMO simulations. Various quantitites can be calculated along the trajectories and a flexible choice of selection criteria used to link the trajectories to specific flow features.

Quasi-geostrophic (QG) diagnostic: A code to derive the upper and lower level forced quasigeostrophic (QG) vertical velocity fields in ECMWF and COSMO data was derived from code in NDDIAG, a diagnostics package developed and supported by NCAS-CMS (National Centre for Atmospheric Science - Computational Modelling Services).

MAP precipitation climatology (Frei, 2004): The precipitation dataset from the MAP project (Frei and Schär, 1998) contains daily precipitation sums for grid cells from 1971 - 1995. Eddy Kinetic Energy Analysis following Orlanski and Katzfey (1991) is used to calculate fluxes and barotropic / baroclinic generation of eddy kinetic energy.

Eddy Kinetic Energy Analysis following Orlanski and Katzfey (1991) is used to calculate fluxes and barotropic / baroclinic generation of eddy kinetic energy.