Winterline or winter line is the term used to describe the false horizon that is formed at

dusk Dusk occurs at the darkest stage of twilight, or at the very end of astronomical twilight after sunset and just before nightfall.''The Random House College Dictionary'', "dusk". At predusk, during early to intermediate stages of twilight, enoug ...

and is visible from certain mountainous parts of the world. The reason for its formation is not clear, but it has been reported that "experts" believe it occurs due to

refraction In physics, refraction is the redirection of a wave as it passes from one transmission medium, medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commo ...

of light when the dust particles, moisture, and smog, rising from the plains below, meet the cooler mountain air, and a 'second horizon' is formed. It is visible from many places throughout the

Himalayas The Himalayas, or Himalaya ( ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the Earth's highest peaks, including the highest, Mount Everest. More than list of h ...

and is very prominent from

Mizoram Mizoram is a states and union territories of India, state in northeastern India, with Aizawl as its Capital city, capital and largest city. It shares 722-kilometres (449 miles) of international borders with Bangladesh to the west, and Myanmar t ...

, and

Mussoorie Mussoorie () is a hill station and a municipal board, in Dehradun city in the Dehradun district of the Indian state of Uttarakhand. It is about from the state capital of Dehradun and north of the national capital of New Delhi. The hil ...

and Hilly regions of Uttarakhand and Nahan, Himachal Pradesh in India between October and February, and the local

Winterline Carnival is named after the phenomenon. Apart from India, winterline occurs in the

Swiss Alps The Alps, Alpine region of Switzerland, conventionally referred to as the Swiss Alps, represents a major natural feature of the country and is, along with the Swiss Plateau and the Swiss portion of the Jura Mountains, one of its three main Physica ...

Gallery

File:Winterline view from Serkawn, Lunglei, Mizoram, India.jpg, Winterline as visible from

File:Winterline sunset view from Serkawn, Lunglei, Mizoram.jpg, Winterline Sunset view from Serkawn,

Lunglei Lunglei (, locally ), formerly rendered Lungleh, is the second-largest town in Mizoram, Northeast India, northeastern India, situated in the south-central part of the state. The town served as the capital of British rule in the Lushai Hills, Br ...

. File:Winterline with Lunglei town foreground Mizoram.jpg, Winterline view with

in frame. File:Winterline Above Dehradun Valley (5291469786).jpg, Winterline above the

Doon Valley The Doon Valley is an unusually wide, long valley within the Sivalik Hills and the Lesser Himalayas, in the Indian states of Uttarakhand, Himachal Pradesh and Haryana. Within the valley lies the city of Dehradun, the winter capital of Uttar ...

File:Winterline Above Mussoorie (5290869225).jpg, Winterline as visible from

File:Winterline.jpg, Winterline as visible from

Landour Landour, a small cantonment town contiguous with Mussoorie, is about from the city of Dehradun in Dehradun district in the northern state of Uttarakhand in India. The twin towns of Mussoorie and Landour, together, are a well-known British Raj-e ...

near Mussoorie File:Winterline Above Mussoorie (5290871907).jpg, Winterline and the

hill station A hill station is a touristic town located at a higher elevation than the nearby plain or valley. The English term was originally used mostly in Western imperialism in Asia, colonial Asia, but also in Africa (albeit rarely), for towns founded by ...

Mussoorie in the foreground

References

{{reflist Geography of Uttarakhand Meteorological phenomena Atmospheric thermodynamics Atmospheric circulation Mussoorie Geography of Dehradun