Among theories advanced to account for the reddish sky in the background is the artist's memory of the effects of the powerful volcanic eruption of Krakatoa, which deeply tinted sunset skies red in parts of the Western hemisphere for months during 1883 and 1884, about a decade before Munch painted The Scream. This explanation has been disputed by scholars, who note that Munch was an expressive painter and was not primarily interested in literal renderings of what he had seen. Another explanation for the red skies is that they are due to the appearance of nacreous clouds which occur at the latitude of Norway and which look remarkably similar to the skies depicted in The Scream. Alternatively, it has been suggested that the proximity of both a slaughterhouse and a lunatic asylum to the site depicted in the painting may have offered some inspiration. The scene was identified as being the view from a road overlooking Oslo, the Oslofjord and Hovedøya, from the hill of Ekeberg. At the time of painting the work, Munch's manic depressive sister Laura Catherine was a patient at the mental asylum at the foot of Ekeberg.