Sometimes a simulation data file can have a number of important dimensions that do not have coordinate variables, i.e., corresponding float, double, or integer variables with the same names.

For example, in the EAMxx-MAM4xx_ne4pg2_202508.nc data file in this folder, dimensions ext_cnt, num_gas_aerosol_constituents, and num_phys_constituents do not have coordinate variables.

Currently (until 2.1.1), these dimensions do not have their sliders in our UI, and they also don't show up in the drop-down menu in the animation control panel. Could we address this issue? I guess we should let the slider labels say something like "Index value: [index value]".

Thanks! @jourdain and @danlipsa