© Stephen Burt
Stratfield Mortimer, near Reading, England, United Kingdom of Great Britain and Northern Ireland
Latitude: 51° 22' 12'' N
Longitude: 1° 2' 24'' W
18 February 2008 1750 (Local Time)
Camera direction: towards WSW
Image P/S code: P.13.11.1
Image I.D.: 5676
Twilight colours are produced by the refraction, scattering or selective absorption of light rays from the Sun in the atmosphere. They can be observed in clear, cloudless air after sunset or before sunrise.
In the direction of the Sun during twilight, a glow called the purple light is sometimes seen. This appears as a segment of a large luminous disk and extends upwards from the horizon, reaching maximum luminance when the Sun is 3° or 4° below the horizon. It then descends and disappears when the Sun is about 6° below the horizon.
On very rare occasions, the top of the twilight arch may become a very noticeable vivid purple colour, more intense than any purple tinge normally seen at twilight. Such extremely visually striking instances of the purple light seem to be associated with either fine volcanic dust in the atmosphere or the occurrence of polar stratospheric clouds.
Between 17 and 20 February 2008, there were widespread observations in central and western Europe of extraordinary, intense purple twilights. This event has been linked to very low stratospheric temperatures and the formation of polar stratospheric clouds (although no polar stratospheric clouds were actually seen by the observer). The photograph here was taken in evening twilight on the 18th from a location in southern England, UK. The true vividness of the colours is difficult to capture in a photograph, but above the bright twilight arch at the top of the photograph there is a distinct purple colour to the sky.
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This photograph was taken at 1845 UTC near Reading in southern England, UK, 28 minutes after sunset and looking west. The ash cloud from the June 1991 eruption of Mt. Pinatubo in the Philippines produced a number of spectacular sunset skies during the autumn of 1991, including twilight purple light on this and other occasions.
Links in the image description will highlight features on the image. Mouse over the features for more detail.
Twilight colours are produced by the refraction, scattering or selective absorption of light rays from the Sun in the atmosphere. They can be observed in clear, cloudless air after sunset or before sunrise.
In the direction of the Sun during twilight, a glow called the purple light is sometimes seen. This appears as a segment of a large luminous disk and extends upwards from the horizon, reaching maximum luminance when the Sun is 3° or 4° below the horizon. It then descends and disappears when the Sun is about 6° below the horizon.
On very rare occasions, the top of the twilight arch may become a very noticeable vivid purple colour, more intense than any purple tinge normally seen at twilight. Such extremely visually striking instances of the purple light seem to be associated with either fine volcanic dust in the atmosphere or the occurrence of polar stratospheric clouds.
Between 17 and 20 February 2008, there were widespread observations in central and western Europe of extraordinary, intense purple twilights. This event has been linked to very low stratospheric temperatures and the formation of polar stratospheric clouds.
This photograph was taken in evening twilight from a location in southern England, UK. It is difficult to record the true vivid nature of the purple glow in a photograph, but a distinct purple colouration can be seen across the sky in the image. The polar stratospheric clouds likely responsible were not seen by the observer.
Links in the image description will highlight features on the image. Mouse over the features for more detail.
Twilight colours are produced by the refraction, scattering or selective absorption of light rays from the Sun in the atmosphere. They can be observed in clear, cloudless air after sunset or before sunrise.
In the direction of the Sun during twilight, a glow called the purple light is sometimes seen. This appears as a segment of a large luminous disk and extends upwards from the horizon, reaching maximum luminance when the Sun is 3° or 4° below the horizon. It then descends and disappears when the Sun is about 6° below the horizon.
On very rare occasions, the top of the twilight arch may become a very noticeable vivid purple colour, more intense than any purple tinge normally seen at twilight. Such extremely visually striking instances of the purple light seem to be associated with either fine volcanic dust in the atmosphere or the occurrence of polar stratospheric clouds.
In mid-February 2008, there were reports from central and western Europe of extraordinary, intense purple twilights. This event has been linked to very low stratospheric temperatures and the formation of polar stratospheric clouds.
The photograph here was taken in evening twilight from a location in southern England, UK. The true vividness of the colours is difficult to capture in a photograph, but above the bright twilight arch at the top of the photograph there is a distinct purple colour to the sky.
Links in the image description will highlight features on the image. Mouse over the features for more detail.
Twilight colours are produced by the refraction, scattering or selective absorption of light rays from the Sun in the atmosphere. They can be observed in clear, cloudless air after sunset or before sunrise.
In the direction of the Sun during twilight, a glow called the purple light is sometimes seen. This appears as a segment of a large luminous disk and extends upwards from the horizon, reaching maximum luminance when the Sun is 3° or 4° below the horizon. It descends and disappears when the Sun is about 6° below the horizon.
On very rare occasions, the top of the twilight arch may become a very noticeable vivid purple colour, more intense than any purple tinge normally seen at twilight. Such extremely visually striking instances of the purple light seem to be associated with either fine volcanic dust in the atmosphere or the occurrence of polar stratospheric clouds.
Between 17 and 20 February 2008, there were widespread observations in central and western Europe of extraordinary, intense purple twilights. This event has been linked to very low stratospheric temperatures and the formation of polar stratospheric clouds. This photograph of the purple light was taken in the evening on the 17th from a location in England, UK. The true vividness of the colours are difficult to capture in a photograph, but above the bright twilight arch there is a distinct purple colour to the sky.
Links in the image description will highlight features on the image. Mouse over the features for more detail.