What About Saana'a?

On last Tuesday's Nightly News, a map of Yemen identified the capital city as "Sanaa". A moment later, a caption below Richard Engel indicated that he was reporting from "Sana'a". The following day, Engel interviewed a man who was identified on screen as the director of the "Saana Institute for Arabic Language". So which is it--Sanaa, Sana'a or Saana? I'll give the Nightly News producers a moment in case they want to call a lifeline. Perhaps the producers just need to calm down a bit and switch to decaf. I'd recommend Sanka'a.