Visualization tools c FreVast Team Feb/2017

Visualization tools for meteorological data

This handout shortly introduces beginners to the different tools for the visualization of meteoro- logical binary data. Most of the Freva plugins already create figures that are helpful for the first interpretation of the analyzed data. However, for a user specific analysis (e.g. comparison of two simulations), A) you need to know the content of the binary data, B) it needs to be modified and C) visualized.

Figure 1: Flowchart for the process of creating a figure from meteorological binary data. The categories A, B, C and D are being used below to classify the capabilities of the listed processing and visualization tools.

Often meteorological data will be in Network Common Data Form (NetCDF; .nc) or Gridded Binary files (GRIB; .grb). You may convert the data to another format (e.g. GRIB to NetCDF; with cdo -f nc copy file.grb file.nc), but be advised, that a conversion is always accompanied with a loss of metadata. The tools listed below, are able to deal with those two and - in a lot of cases - also other data formats. A more comprehensive collection of freely available and licensed software to display and manipulate NetCDF files is listed here: http://www.unidata.ucar.edu/software/netcdf/ software.html.

tool installed CIP free/open source script based GUI description

1 Information (A) ncdump -h   A text representation of the NetCDF data (shows variables, dimensions, metadata, history) Fhttps://www.unidata.ucar.edu/software/netcdf/netcdf-4/ newdocs/netcdf/ncdump.html cdo sinfo   Shows spatial & temporal coordinates & dimensions cdo showvar   Shows variables name cdo showdate   Shows dates cdo griddes   Shows grid description; More info on CDO reference card: Fhttps://code.zmaw.de/projects/cdo/embedded/cdo_refcard.pdf

2 Quick View (A, C) ncview    A graphical browser for NetCDF files Fhttp://meteora.ucsd.edu/~pierce/ncview_home_page.html

1 Visualization tools c FreVast Team Feb/2017

3 Data Processing (A, B) CDO   Climate Data Operators for GRIB- & NetCDF-files, de- signed for, but not limited to, climate & Numerical Weather Prediction (NWP) model data (type: cdo) Fhttps://code.zmaw.de/projects/cdo/wiki/tutorial Fhttps://code.zmaw.de/projects/cdo/embedded/cdo.pdf NCO   NetCDF Operators - a toolkit to manipulate & analyze geo- physical data stored in netCDF-accessible formats (type e.g. ncrename,...); NCO reference card: Fhttp://nco.sourceforge.net/nco_rfr_crd.pdf Fhttp://nco.sourceforge.net/

4 Data Processing & Visualization (A, B, C, D) R    Open source software for statistical computing & graphics (type: Rscript) Fhttps://www.r-project.org/ Rstudio    An integrated development environment (IDE) for R (type: rstudio) Fhttps://www.rstudio.com NCL    NCAR Command Language - analysis & visualization of at- mospheric sciences’ data; website provides lots of examples (type: ncl) Fhttp://www.ncl.ucar.edu/index.shtml Python    Open source programming language for data analysis (type: python) Fhttps://www.python.org/ GrADS    Grid Analysis and Display System - interactive desktop tool for the analysis & display of earth science data (type: grads) Fhttp://cola.gmu.edu/grads/gadoc/tutorial.html XGrads   GUI for the visualization of gridded data with GrADS (type: module load xgrads; xgrads; click on Help) PlotEngine    Command line tool to produce figures (type: plot engine) FAQs: plot engine --faq Gnuplot    A command line driven graphing utility (type: gnuplot) Fhttp://www.gnuplot.info/ Ferret    A visualization & analysis environment designed to meet the needs of oceanographers & meteorologists (type: ferret) Fhttp://ferret.wrc.noaa.gov/Ferret/ GNU Octave    Scientific Programming Language, drop-in compatible with many Matlab scripts (type: octave) Fhttps://www.gnu.org/software/octave/ Matlab  $   Matrix Laboratory - statistical computing & graphics for engineering & scientific problems (type: ) Fhttps://de.mathworks.com/products/matlab/features.html IDL  $   Interactive Data Language - analysis & visualization of data for scientists & engineers (type: idl) Fhttp://www.harrisgeospatial.com/ProductsandSolutions/ GeospatialProducts/IDL.aspx GDL   An open source incremental compiler compatible with IDL Fhttp://gnudatalanguage.sourceforge.net/

5 Image Post-Processing (C, D) convert   command line software to edit & convert images Fhttps://www.imagemagick.org/script/index.php

c FreVast Team

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