QUESTION: I am attempting to export the top of a plume from EVS to an ESRI grid in order to ascertain point elevations.  What is the best way to do this or does one of the example projects have this to review?

First, we do not export ESRI Grid files.

Second, a plume, or rather the subset of a volume based on all values above some threshold for an analyte, will not generally result in a single contiguous volume.  Therefore, you cannot assume that there will be a single TOP surface to this subset.

If you use plume_shell, which gives you the external surface of the volumetric subset and pass that to slope_aspect_splitter, you can use the default Subset Expression:

Slope < 89.9

to give you the upward facing surface.  This is akin to the top half of a sphere (assuming your plume was a sphere).  The output of slope_aspect_splitter can be exported as a shapefile with write_vector_gis and I assume that it could be converted to an ESRI Grid within ArcGIS, however, please be reminded that it is likely there may be multiple objects (surfaces) at some X-Y locations as discussed in the second paragraph.