This blog
http://teochiewkia2010.blogspot.co.uk/2010_03_01_archive.htmlhas an article containing a list of Penang Eurasian surnames, including Aeria. As all the other names on the list are European, so Aeria is likely to be (perhaps you already know this). It may have been altered in transition from one language to another. Maybe an Iberian origin, Spanish or Portuguese.
(All guesswork)