Change your preferences here.
Deals damage and has a 10% chance to lower the target's Attack by one stage.
Aurora Beam's measly 10% chance to lower the opponent's Attack hardly justifies the drop in power from Ice Beam. Aurora Beam should never be seriously considered for a moveslot on a competitive Pokemon.
Ice Beam is a more powerful option with a chance to freeze the target.
Blizzard is a much more powerful but less accurate option with a chance to freeze the target.