Calculates the vertical component of the curl (ie, vorticity) at each grid
point using finite differencing on the grids provided. It is assumed that
uexpr gives the U Wind component, and that
vexpr provides the V Wind component.
The alghorithm used for the finite difference calculation is described as an Example for the
The function assumes an X-Y varying dimension environment, and will not operate unless that is the case. The
definecommand can be used in conjunction with the
hcurlfunction to create 3 or 4 dimensional fields of vorticity, from which vertical cross-sections could be displayed.
The boundaries of the grid are set to missing.
The radius of the earth used in the calculation is in meters; thus the units of the wind expressions provided would normally be m/s.
To display the vorticity:
If you want to display a vertical cross section of vorticity, you first need to calculate it over a 3-Dimensional region:
set lon 0 360
set lat -90 90
set lev 1000 100
define vort = hcurl(u,v)
set lon -90