My first instinct is to say the first syllable as AIR. But if I had to attempt it out loud in front of an
Ariana, without knowing how it was pronounced, I think I'd deliberately guess AHR.
I'd pronounce
Ariana as -AHna, and I pretty much always say -
ANna for any names that end with -anna. I can get used to names pronounced whichever way, though. It's not that confusing - if you actually know a person with the name, you just say and spell it like tell you to. For example,
Diana is pronounced like
Dianna, but
Leanna and
Liana are probably different. No biggie.
I don't know if I count them as the same name or not.