Standard Chartered Weather Photographer of the Year 2023: From dusk to dawn
by Kirsty McCabe, FRMetS
If you are wondering what time of day is best to take weather photographs you can’t go far wrong with the hour or so after sunrise, or the hour before sunset. Known as the golden hour, this magical light makes for some beautiful photographs.
The rising or setting sun can also highlight the clouds in the sky, as you can see with these spectacular Mammatus clouds.
These are associated with large cumulonimbus clouds and are more visible when the sun is low in the sky. The bulges at the base of the cloud are formed by turbulence within the cloud.
As for the sky itself, it can take on wonderful hues from fiery reds to the deepest purples at dawn and dusk. But why does the sky change colour?
It’s all thanks to a combination of factors; the colours in sunlight, the angle at which the sun’s rays travel through our atmosphere, the size of atmospheric molecules and particles, and not forgetting the way our eyes perceive colour.
When the sun’s light reaches our atmosphere, it bumps into tiny molecules of nitrogen and oxygen, which scatter or deflect the light. The amount of scattering depends on the wavelength of the light — an effect known as Rayleigh scattering.
The shorter wavelengths, the violets and blues, are scattered most strongly so more of the blue light is scattered towards our eyes than the other colours. Since you see the blue light from everywhere overhead, the sky looks blue. In case you’re wondering why the sky isn’t purple, that’s down to biology and the fact that our eyes, specifically the cones or colour receptors in our retina, are more sensitive to blue than violet.
But why does the sky take on glorious hues of yellow, orange, pink and red as the sun rises or sets? This is also due to Rayleigh scattering. At dusk and dawn, the sun is very low in the sky, so the sunlight we see has travelled through a much thicker amount of atmosphere. This increased distance causes more of the blue portion of the sun’s rays to scatter away from our eyes, leaving relatively more of the yellow, orange and red light for us to see.
In contrast to what you might think, dust and air pollution do not make a sunset more dramatic. The most vibrant sunrises and sunsets actually occur in winter thanks to a combination of lower humidity, lack of air pollution and better clouds.
The image below is a mock mirage sunset, where the sun is distorted and appears to be sliced horizontally. This can occur when there are one or more shallow layers in the atmosphere with a temperature difference between each layer, known as temperature inversions. The sunlight is refracted more as it travels through colder layers than warmer ones distorting how it appears.
This photograph also captures an inferior mirage where the distant buildings in Southend appear to be elevated above their normal position. An inferior mirage is also an optical phenomenon due to a temperature inversion.
Standard Chartered Weather Photographer of the Year shortlist
The public vote for the 2023 Standard Chartered Weather Photographer of the Year competition is now open! Now in its eighth year, the competition is a window to the vastly different climates experienced across the world and provides an international platform to highlight global weather events.
The 2023 competition showcases some of the world’s most striking weather phenomena, alongside images that narrate compelling stories about the impacts of climate change. Highlights include rare red sprite lightning, dramatic tornadoes and cloud formations, ice-covered landscapes, flood-filled streets, dry riverbeds and deadly forest fires. The shortlisted images, from photographers across 94 countries, emphasise the beauty and fragility of our weather and the urgency to limit further global warming while adapting to the changes we are already experiencing.
The Society now invites you to vote for your favourite photograph from a shortlist of the competition's finest entries. The winners of the 2023 Standard Chartered Weather Photographer of the Year competition will be announced on Thursday 5 October, after the public vote closes on 24 September.