The visualization software Met.3D can be used for interactive visual exploration of meteorological phenomena in ERA5. This page provides a short guide towards using Met.3D for interactive 3D visual analysis of ERA5 data.
Introduction
The ERA5 reanalysis dataset (ECMWF Reanalysis 5th Generation) reanalysis data is the most recent , global weather dataset reanalysis data covering the time-period from 1950 until today. The data is obtained by combining a numerical weather prediction model with empirical observations (4DVar data assimilation in CY41R2 of ECMWFs IFS). It contains estimates of atmospheric variables, such as air temperature, pressure, and wind, as well as surface variables such as rainfall and soil moisture. The meteorological variables are available with hourly temporal resolution on a global data grid with approximate horizontal resolution of 31km and 137 vertical model levels.
- For more information about ERA5, please see the ECMWFs documentation
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Met.3D can be used for interactive visual exploration of meteorological phenomena in ERA5. Available methods used for this visual data exploration study Examples of available visualization methods include:
- sliding of horizontal and vertical cross-sections through 3D data-cubes
- computation of 3-D isosurfaces with interactive variation of isovalues
- direct volume rendering of clouds using raycasting
- flow visualization via wind barbs and trajectories.
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Step by step procedure
The following steps are performed as part of this study.necessary for analysing ERA5 data with Met.3D.
- ERA5 data acquisition
- Pre-processing of ERA5 data to a regular grid (Met.3D currently requires data on regular grids)Obtain ERA5 data on regular lat-lon grid
- Visual exploration of ERA5 using the features graphical user interface of Met.3D
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ERA5 data
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acquisition
ERA5 data is freely available for download.
- For a detailed description on how to download ERA5 data, please see: https://confluence.ecmwf.int/display/CKB/How+to+download+ERA5.
- Alternatively, the ERA5 data is also available at the German Climate Computing Center (DKRZ). For details, please see: https://www.dkrz.de/up/services/data-management/projects-and-cooperations/era
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2 Pre-processing of ERA5
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to a regular grid
Met.3D requires gridded meteorological (simulation) data on a regular lat-lon regularly spaced grid.
- The
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- data handling section of this documentation provides an overview about the
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- supported data and file types.
- If you download ERA5 data on a regular grid, as provided by the ECMWFS download options, you should be able to directly load the data into Met.3D without any other processing, and start your interactive visual data exploration.
- If the data is on a Gaussian or Spectral grid, you need to interpolate the data to a regular grid before you can analyse it using Met.3D.
The Climate Data Operators (CDO) provide a convenient way to interpolate ERA5 data onto a regular grid.
- For a detailed documentation of CDO, please see: https://code.mpimet.mpg.de/projects/cdo/.
The stereographic conversion section provides for example, code snippet The remapping section of this documentation outlines the procedure for the conversion of regular grid to a stereographic grid, which was performed in this study.
---> Minimal example CDO gridfile regular lat-lon grid (cylindrical proj): /MM/project.notes/mcao.configfiles/ERA5_postprocessing/CDOGridFiles_RegLL/gridLatLon_forCaseStudies.txt
---> Minimal example CDO gridfile for data in a polar stereographic projection: MM/project.notes/mcao.configfiles/ERA5_postprocessing/CDOGridFiles_StereographicProj/gridPolarStereo_forCaseStudies.txt
---> Minimal example CDO command for interpolation from Gaussian / Spherical grid to regular lat-lon: MM/project.notes/mcao.configfiles/SI_HelperTools
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spectral or gaussian grids to regular lat lon grids.
The stereographic conversion section of this documentation outlines the procedure for the conversion of a regular grid to a stereographic grid.
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Visual exploration of ERA5 using the features of Met.3D
Results
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Start your 3D interactive visual data analysis. The getting started section summarizes first steps.