The screenshot show different operators in VisIt that may be used to transform a cartesian grid to spherical grid. One issue that may come up with such transformation is that the grid does not wrap around. There are two options to overcome this issue
1a) Use "Dual Mesh" operator to transform the spherical grid to cell centered
1b) The plots will not be interpolated, and one can specify centering to "Nodal" in corresponding plots
2) Use "Index Select" to wrap the spherical grid.
The screenshots with these options are include here.