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- type of visualisation (e.g. geographical map, cross section, vertical profile, tephigram)
- parameters specific to that plot type (e.g. geographical area, cross section line, min/max axes values)
- plot position within the page (several plots can share a page)
- how to overlay different data in the same plot (e.g. icon drop rules, data overlay control)
- plot decoration (e.g. draw a frame around the plot)
Without a View specification, Metview would not plot anything. If you do not provide a View, then Metview will use a sensible default View. For instance, when you have previously visualised visualise a GRIB icon by just clicking the icon and selecting option Visualise. A a Display Window was is automatically generated showing a default Geographical View containing a global map in a Cylindrical projection.
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- more than one globe's worth of area in a Cylindrical projection.
- data overlay control: 5 infra-red bands (Meteosat-7, Meteosat-10, GOES-13, GOES-15, MTSAT-2) and a temperature field.
- coastlines attributes (e.g. line colour, lat/long increments,...).
Eight View specifications are currently available:
| Name | Usage (Used for plotting or Plotting specification for) |
|---|---|
| Geographical View | geographic-based data plots (default View) |
| Cartesian View | plots that are not to be displayed on a map |
| Cross Section View | cross section plots |
| Vertical Profile View | vertical profile plots |
| Average View | average (zonal or meridional) cross-section plots |
| Annotation View | text boxes |
| Hovmøller View | Hovmøller diagram plots |
| Thermo View | thermodynamic diagram plots |
The Geographical View 
This is the default View for plotting geographic-based data. This View was discussed previously in A Quick Tour of Metview. in Customising Your Plot.
The Cartesian View 
This view is for plots that are not on a map, and will be covered in another session: Graph Plotting in Metview.
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The Cross Section View icon is a plotting specification for cross section plots along a given arbitrary transect line.
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Create a new Cross Section View icon
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, Visualise it and drop the t_fc24.grib icon into the resulting Display Window.
A default cross section along the Equator is generated. This is an alternative way to view your data - instead of a geographical plot for instance.
Inspect the GRIB icon (right-click on it and choose examine) to see the type of input data this View requires - it should be gridded data (rather than spherical harmonics) and it should contain fields at multiple vertical levels.
If the data is given in model levels and you want the orography and the vertical axis of the plot in pressure levels, rather than model levels, then a Logarithm of Surface Pressure field must also be provided.
To customise the transect line (coordinates along which the cross-section is calculated), do the following: Edit the Cross Section View icon
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and either click on the Geography Tool button to bring up an editor (or type the coordinates by hand).
Save/OK the changes and re-visualise the data with this new cross section.
Note that you can still drag any valid Contouring icons you may have into the Display Window when visualising a cross section. For instance, apply the given shade icon. You may want to customise it and try different configurations.
Inspect the GRIB icon (right-click on it and choose examine) to see the type of input data this View requires - it should be gridded data (rather than spherical harmonics) and it should contain fields at multiple vertical levels. This view accepts data stored in either pressure levels or model levels (optionally supply a Logarithm of Surface Pressure field to transform model levels to pressure levels).
The Vertical Profile View 
The Vertical Profile View icon is a computation/plotting specification for vertical profile plotsprofiles.
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Create a new Vertical Profile View icon
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, Visualise it and drop the t_fc24.grib icon into the Display Window.
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The result shows a vertical profile at a point (or averaged over an area). Experiment with this icon in a similar way to how you did with the Cross Section View icon.
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To customise the line displayed in this plot, do the following:create a new instance of Graph Plotting and rename it to vdline.
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Edit it, setting the following parameters:
Graph Line Style | Dash |
Graph Line Colour | Black |
Graph Line Thickness | 5 |
Save/OK the changes and drag it into the Display Window.
The Average View 
The Average View icon is a plotting specification for average (zonal or meridional) cross-section plots over an area.
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Create a new Average View icon
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, Visualise it and drop the t_fc24.grib icon into the Display Window.
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A default meridional average over the globe cross-section global area is generated. Examine the horizontal axis - it only contains E/W co-ordinates, because the data values have been averaged along N/S meridional lines
Experiment with this icon in a similar way to how you did with the Cross Section View icon. You can use a Contouring icon, e.g. the shade icon, to style the contours of the plotting.
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The Hovmoeller View icon is a computation/plotting specification for Hovmøller diagram plots diagrams along a specified arbitrary transect line or a rectangular area. The diagram displays a two-dimensional graph with latitude or height as one axis and time as the other.
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Create a new Hovmoeller View icon
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, Visualise it and drop the t_ts.grib icon into the Display Window.
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A default diagram derived from a transect line along the Equator is generated.
Examine the GRIB icon to see the sort of input data this View requires,
Three types of Hovmøller diagrams can be produced:
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Experiment with this icon by testing the above types and investigating other input parameters. Please note that type Vertical Hovm requires the following input GRIB data: t_ts_nlevels.grib. Examine and compare this GRIB data with the previous one. As previously, you can use a Contouring icon to style the contours of the plotting.
This view requires data at different time steps. Examine the GRIB icons to see the fields used for these examples.
The Thermo View 
The Thermo View icon is a plotting specification for Thermodynamic diagram plots from a suitable GRIB or BUFR data source. In such a diagram, temperature, humidity (represented by the dew point) and wind values are displayed with respect to pressure.
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- create a new instance of this icon and rename it to vdwind.
- Edit it, setting the following parameters:
Wind Field Type | Flags |
Wind Flag Colour | Coral |
| Wind Flag Length | 1.3 |
Wind Flag Thickness | 2 |
- Save/OK the changes and drag it into the Display Window.
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