Two main ideas shaped the investigation of this dataset -- how the variables change as the altitude is increased, and the possible relationships between one or more variables.
The motivation for the first is that analysing the variables on the ground, while directly relevant to everyday experience, may not provide the whole story. As such, it is hoped that investigating the variables at higher altitudes may provide extra insights into the weather, specifically that at ground level.
The motivation for the second is that all three of the variables in the dataset are ultimately determined from one physical entity: the gaseous atmosphere. As such, it would be expected that meteorological phenomenon, for example, low pressure zones or cold fronts, would be manifest in more than one of the variables. As such, visualising more than one variable simultaneously might make these phenomenon easier to see and interpret.