When the sun is about to rise over a ridge that’s pretty high and there are diffuse clouds a little higher and closer than the ridge, and if it all comes together just so, the sun will cast a silhouette of the ridge line against the clouds. Sometimes the silhouetted peaks lie behind the first ridge, in which case the sun is projecting an image of something that would be invisible otherwise.
It’s not a particularly rare phenomenon, but you need to pay attention or you might miss it. Here are a few Himalayan examples from my photo archive. I suppose mountain ranges in other parts of the world might show this phenomenon too. Does anyone have any examples?
Kangchenjunga Conservation Area, Eastern Nepal. Here you can see the spire that’s casting the shadow. May 2014.Thak Khola, Jomsom District, Nepal. Here, where the Kali Gandaki River passes between the mountain masses of Dhaulagiri and Annapurna, morning sun casts a silhouette of the Annapurna range on low stratus clouds. July 2001.Olangchung Gola, Taplejung District, Nepal. The sky was clear this fine spring morning, so I’m not sure what is going on. Maybe the silhouette of invisible peaks is being cast by light refraction. May 2014.Upper Barun Valley, Sankuwasabha District, Nepal. Peaks silhouetted onto these clouds define Nepal’s border with China. May 2017.This one is the sun coming up behind limestone pinnacles that tower over the right bank of Tiger Leaping Gorge (虎跳峡) in northern Yunnan Province, China. May 2009.
