The Elemental Nova Skill of the Mage Class is not affected by any sources of area scaling, including its own 100% scaling in the tree.
Here you can see the nova with barely any scaling vs. over 200% area scaling. The first screenshot shows me being a little closer and hitting with the initial nova range, thus applying ailments. The second screen shows the area scaling visually increasing the range but not increasing the actual hit range, thus not hitting and not applying any ailments.