Question: The title of this Swedish-French crime television series in English refers to a natural phenomenon where the sun remains visible for what?

Passages:
A solar term is any of 24 points in traditional East Asian lunisolar calendars that matches a particular astronomical event or signifies some natural phenomenon.  The points are spaced 15° apart along the ecliptic and are used by lunisolar calendars to stay synchronized with the seasons, which is crucial for agrarian societies.  The solar terms are also used to calculate intercalary months in East Asian calendars; which month is repeated depends on the position of the sun at the time. A sunbreak is a natural phenomenon in which sunlight obscured over a relatively large area penetrates the obscuring material in a localized space.  The typical example is of sunlight shining through a hole in cloud cover.  A sunbreak piercing clouds normally produces a visible shaft of light reflected by atmospheric dust, called a sunbeam.  Another form of sunbreak occurs when sunlight passes into an area otherwise shadowed by surrounding large buildings through a gap temporarily aligned with the position of the sun. Oregon Field Guide is a weekly television program produced by Oregon Public Broadcasting focusing on recreation, the outdoors, and environmental issues in the state of Oregon.  The show has become part of the Oregon zeitgeist.  Steve Amen is the show's host and executive producer.  Named for the field guides used to identify plants, animals, and natural phenomenon, the wide-ranging series covers Oregon natural history, outdoor recreation, conservation, agriculture, rural life, and other local subjects.  Produced with deep narratives rather than short segments, 13 half-hour and one full-hour episodes are shown per year. The midnight sun is a natural phenomenon that occurs in the summer months in places north of the Arctic Circle or south of the Antarctic Circle, when the sun remains visible at the local midnight.  Around the summer solstice (approximately 21 June in the Northern Hemisphere and 22 December in the Southern Hemisphere) the sun is visible for the full 24 hours, given fair weather.  The number of days per year with potential midnight sun increases the closer towards either pole one goes.  Although approximately defined by the polar circles, in practice the midnight sun can be seen as much as 55 miles (90 km) outside the polar circle, as described below, and the exact latitudes of the farthest reaches of midnight sun depend on topography and vary slightly year-to-year. Sombrero (Spanish for "hat", means "shadower") in English refers to a type of wide-brimmed hat from Mexico, used to shield from the sun.  It usually has a high pointed crown, an extra-wide brim (broad enough to cast a shadow over the head, neck and shoulders of the wearer, and slightly upturned at the edge), and a chin string to hold it in place.  In Spanish, sombrero refers to any wide-brimmed hat. Instagram Pier (officially Western District Public Cargo Working Area ) is a pier located on the waterfront of Sai Wan.  Many residents of Sai Wan often go there for wandering, resting, walking their dogs and fishing.  Recently (since at least 2010), it has become a popular place for witnessing sunsets and shooting photos.  The picturesque surrounding area seen from the pier has taken on the nickname -"Mirror of the Sky", since many photographs are taken of the reflective shoreline there.  The name refers to the natural phenomenon of reflections seen on the unusually thick layer of water remaining on the ground after rainfall.  The water clearly reflects the sky and shadows of people and objects standing on the horizon.  Sunsets often add a stunning effect to this "Mirror of the sky” phenomenon. Horsetail Fall, located in Yosemite National Park in California, is a seasonal waterfall that flows in the winter and early spring.  The fall occurs on the east side of El Capitan.  If Horsetail Fall is flowing in February and the weather conditions are just right, the setting sun illuminates the waterfall, making it glow orange and red.  This natural phenomenon is often referred to as the "Firefall", a name that pays homage to the manmade Firefall that once took place in Yosemite. The Law of Gravity refers to the natural phenomenon known as "gravitation". Případy 1.  oddělení ("Cases of the 1st Department" in English) is a Czech crime television series.  The series is based on real criminal cases investigated by Czech Police.  People involved in screenwrighting of the series include Jan Malinda (journalist MF Dnes) a Josef Mareš (chief investigator oat the real 1st department).  The series was selected the best Czech crime television series in last decade.  Main characters are based on real life investigators and other people.  The cases reflect some of the most famous real criminal cases of the modern Czech Republic. Midnattssol (French: "Jour polaire" , English: Midnight sun ) is a Swedish-French crime television series from 2016.  It started airing on SVT on 23 October 2016.

Supporting sentences:
The midnight sun is a natural phenomenon that occurs in the summer months in places north of the Arctic Circle or south of the Antarctic Circle, when the sun remains visible at the local midnight.  Around the summer solstice (approximately 21 June in the Northern Hemisphere and 22 December in the Southern Hemisphere) the sun is visible for the full 24 hours, given fair weather.