Required only for time-averaged data. The average period represented in the source variable before taking the average. The begin and end values of the time period used to create the averaged data using the same time units and base as in the units attribute. Type is double. The portion of a time unit actually used.
Level coordinate variable.
Level is used for the vertical or 'Z' dimension in a variable. If the level is not one of these, an arbitrary name may be chosen. If the level does not use one of these, the units should follow the Unidata udunits standard , where possible. Type is float. Type is float.