Snow Upon the Desert is a romantic novel set in Cairo, and the first novel Agatha Christie wrote. She sent it to several publishers under the pseudonym Monosyllaba, but it was rejected and subsequently never published.
A character in Death on the Nile, Salome Otterbourne, is a novelist who’s writing romance novels. One of her books is called Snow on the Desert's Face. The title might be inspired by Christie’s own book.