Early risers on the coast this morning might have caught a glimpse of a rare sight on the horizon: the silhouette of Cap Corse in Corsica, around 100 nautical miles away.
Residents in towns and cities right along the Côte d’Azur and Liguria have taken to social media to share images of the Ile de Beauté as seen from the south of France.
Météo France forecaster Georges Knopf, who is based in Nice, has explained the phenomenon to local press, saying: “In the winter, the air is often drier and therefore purer. Thanks a dry, warm, down-slope [foehn] wind that occurs on the downwind side of a mountain range], northwesterly winds pass over the mountains.”
The silhouette of Corsica, as it was seen this morning, is in fact a mirage. As Knopf explains, the winds continue over the sea, warm up and become more humid. Thus the mountains are reflected, thanks to atmospheric refraction, in the lower levels of air. It's an effect that allows us to see beyond the 'curve of the earth'.
While true sights of Corsica can usually only been seen from high altitudes on the Côte d’Azur, residents on the coastline are only able to see the reflected mountains when the conditions described above are perfect.
It's certainly unusual to wake up to a view of other land on the horizon, but Knopf says the event is much more likely on clear, cold winter mornings... An excuse to wake up a little earlier for a morning coffee!