vcRefMagnitudeF = 5.0, Defines the reference vector magnitude. Use this to adjust the size of the vectors. gsn_csm_vector_scalar_map_ce is the plot interface that draws a vector plot over a scalar contour plot. vcMinDistanceF = 0.017, Thins the vectors vcRefAnnoOrthogonalPosF = -1.0, Moves the reference vector up. infoTimeStamp is a utility for creating a time stamp at the bottom of the figure. The arguments are the workstation, the size of the text, and the right string. The left string is automatically generated and includes the time and date of the plots creation. gsn_csm_pres_hgt_vector is the plot template that draws vectors over a pressure height plot. Note that vcMapDirection must be set to False in order for the vectors to be pointing in the right direction. In V6.2.0, this resource will be set to False by default for the gsn_csm_pres_hgt_vector function. There is another example of this template: example 7 in the pressure/height vs latitude applications page. To turn off vector clipping, set the resource vpClipOn to False. This resources was added in version a034. Polymarkers are added to each plot using gsn_add_polymarker so you can see locations of the vector coordinates. The mask area specifier names are part of the predefined group names available in the 'MediumRes' map database. Source.