The NetCDF CF reader#

Note

This document is part of a series teaching how to Create a multi-variable image / animation from a coupled ice sheet - climate simulation

You can use the NetCDF CF reader to load data on regular (and distorted) grids.

Issues:

  • The reader cannot handle negative time information (will give an error along the lines of “start + count exceeds dimension bounds”).

  • The reader cannot display distorted grids in the plane (e.g. most ocean models)

  • The reader cannot handle a 2D field that has a depth axis (use cdo -setzaxis,surface INFILE OUTFILE or ncwa -a NAME_OF_DEPTH_DIMENSION INFILE OUTFILE to prepare files; affects a lot of MPI-OM output).

  • Ocean models tend to give positive values for depth. That requires a couple switches in the reader, see Load NEMO 3D data with the netCDF CF reader.

  • For MPI-OM velocities, first use cdo -mrotuvb to get data to North/South East/West orientation, and interpolate u and v onto the cell centers.

  • Nemo grids cause weird hick-ups.

  • One file with many time steps tends to be a lot faster than many files with one timestep each.

Open a file with the standard NetCDF Reader#

Use File->Open or the top-left icon (see The Paraview main screen), chose the desired file and select NetCDF Reader when prompted.

../../../../../../_images/chose-reader.png

For a spherical projection use Spherical Coordinates and (for most cases) use Replace Fill Value With Nan

../../../../../../_images/spherical-nans.png

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