This icon is a plotting specification for average (zonal or meridional) cross-section plots. It specifies the averaging area and the axis details as well as the plot positioning in the plot frame of the display window / paper sheet and the overlay of different data units in the same plot.
It allows to obtain an average cross-section plot directly from a suitable (multi-level) data unit without resorting to the use of the Average Data application icon. It is used for visualisation purpose only since the computed output values (e.g. the netCDF file) are not available to the user.
It allows to create an average cross section plot from either a suitable (multi-level) data unit or a Average Data application icon. If a data unit is selected the computed output values ((e.g. the netCDF file) are only used internally and are not available to the user. This option is preferred when the main purpose is visualisation only. If a Average Data application is selected a consistency check is performed between both set of input parameters.
Further details on the role and usage of View icons in the visualisation process, please see Views.
The macro language equivalent is maverageview().
The Cross Section View Editor
Bottom Level
Specifies the lower limit of the cross section, as a pressure level (hPa) or model level (η levels).
Top Level
Specifies the upper limit of the cross section, as a pressure level (hPa) or model level (η levels).
Vertical Scaling
Specifies the type of vertical axis - Linear or Logarithmic.
Interpolate Values
Specifies whether to interpolate vertically the cross-section values into a regular set of interpolated vertical levels. Choosing not to interpolate returns a cross section data matrix with values at the original levels.
Note - if you need to use the cross section data in calculations further down the stream you should not interpolate.
Line
Specifies the coordinates of a transect line along which the cross-section is calculated. Enter coordinates (lat/long) of a line separated by a "/" (easternmost lat and long, westernmost lat and long). Alternatively, use the coordinate assist button.
Note that it is possible to define a line through either pole by describing the line’s coordinates as follows. First, when specifying the latitudes of the two points, imagine that the latitude values go above 90 when you cross the North Pole and below -90 when you cross the South Pole. Next, if you wish a straight line, ensure that the two longitude values are the same as each other. An example demonstrates this. Say you wanted to defined a straight-line cross-section from 60S/25E to 60S/155W. This would be specified as -60/25/-120/25. The fact that one of the latitude values is below -90 indicates to Metview that a cross-section going through the South Pole is desired. Once this has been established, the fact that the two longitude values are identical tells Metview to use a straight line through the pole. If this is the intent, then only one unique longitude value is required, as the other one can be deduced. Giving Metview two different longitude values will cause a cross-section consisting of two curves to be produced.
Wind Parallel
Setting this option to On will produce a cross section plot of the projection of the wind onto the cross section plane (going from a 3D wind field to a 2D wind field projection). This is plotted using wind arrows. Valid values are On/Off.
Wind Perpendicular
Setting this option to On will produce a cross section plot showing the projection of the horizontal wind components onto the direction perpendicular to the cross section plane. The result is a one-dimensional quantity and is plotted with contour lines. Also produced is another cross section plot of the W component of the wind. Valid values are On/Off.
Wind Intensity
Setting this option to On will produce a cross section plot of the scalar wind intensity, plotted with contour lines. If one of the previous two parameters is On, then the intensity is that of the specified projection. Also produced is another cross section plot of the W component of the wind. Valid values are On/Off.
Lnsp Param
Specifies the parameter number of the Lnsp data, if you are using non-ECMWF data - ECMWF uses specific parameter numbers different from the WMO ones. Enter whichever parameter number is appropriate for your data.
U Wind Param
Specifies the parameter number of the U wind component data, if you are using non-ECMWF data - ECMWF uses specific parameter numbers different from the WMO ones. Enter whichever parameter number is appropriate for your data.
V Wind Param
Specifies the parameter number of the V wind component data, if you are using non-ECMWF data - ECMWF uses specific parameter numbers different from the WMO ones. Enter whichever parameter number is appropriate for your data.
W Wind Param
Specifies the parameter number of the W wind component data, if you are using non-ECMWF data - ECMWF uses specific parameter numbers different from the WMO ones. Enter whichever parameter number is appropriate for your data.
Horizontal Axis
Specifies the plotting attributes of the horizontal axis. An Axis Plotting icon can be dropped here.
Vertical Axis
Specifies the plotting attributes of the vertical axis. An Axis Plotting icon can be dropped here.
Common View Parameters ????
supply custom axis definitions