Stadium of light: Dramatic double rainbow illuminates football match




Nature provided a stunning backdrop to a football match last night in the form a dramatic double rainbow.



The colourful bow arched over the Keepmoat Stadium yesterday evening, as players from Doncaster Rovers and Tottenham Hotspurs filed onto the pitch.

The players line up for their second round Carling Cup match as a double rainbow arches over the stadium

A rainbow is created by both reflection and refraction. Sunlight shines on raindrops and the light is reflected back towards the observer.



The raindrop also acts as a prism. The light is bent or refracted as it enters the water and splits into the full spectrum of colours from red to indigo.

The colours are so vivid here because the water droplets are between one and two millimetres in size, any smaller and the rainbow appears hazy.



The sky is brighter underneath the bow because raindrops scatter light inside the arc as well. When you consider the time of day this occurred, the darker sky is being accentuated because the sun is about to set, creating a dramatic contrast with the dark clouds above the stadium. The stadium lights also illuminate the sky in relation to where the photograph is being taken from.

Rainbows are highest in the sky when the sun is lowest. This rainbow lit up the sky at a 7.30pm kickoff because summer days are longer.

The optical phenomena are clearest in early morning and late afternoon when the sun is closer to the horizon. This is because they are always centred around an imaginary point directly opposite to the Sun in the sky – the so-called anti-solar point. So the lower the sun is the higher the bow.



Met Office spokesman John Hammond said: 'The smaller the rain drops the clearer the rainbow will be.

'Looking at the weather for South Yorkshire last night, light rain and drizzle falling over the stadium combined with breaks in the cloud allowing the sun to shine through just before it set, provided ideal conditions for the rainbow to form. It’s a case of being in the right place at the right time to see such a clear and colourful rainbow'.



Why you will never seen a rainbow at noon in summer

However, you will never see a rainbow at noon in summer because light leaves raindrops at an angle of 42 degrees as it passes from water to air. This angle is significant because it means rainbows won't form if the sun is higher than 42 degrees up in the sky.



In 1831, the painter John Constable, well-known for depicting stormy skies, noted that rainbows were not visible in England during the middle of the day from April through to August.

To form a secondary bow like the one in the picture, light must bounce twice within a water droplet, leaving at an angle of 51 degrees. The outer bow always appears as a ghostly arch because each time the beam of light is reflected the intensity of the resulting bow is one tenth of the first.

It is also known as a second-ordered rainbow because red is seen on the inside edge rather than the outside.