Double Rainbows and anti crepuscular rays

Double rainbows and anticrepuscular rays are rare atmospheric phenomena that invite us into a different way of seeing. When they appear together, they create a moment of celestial symmetry. Arcs of refracted light meeting bands of shadow cast in the opposite direction. These skybound events are fleeting and often unnoticed. However when we witness them, they feel like standing in the presence of something ancient and enchanted.

A double rainbow occurs when sunlight is reflected twice inside raindrops, forming two concentric arcs in the sky. Anticrepuscular rays, on the other hand, are bands of light and shadow that appear to converge at the point opposite the sun. Often appearing just after sunrise or before sunset.

Together, they offer a visual dialogue

Light meeting light, shadows pointing back to their source. Reminding us that the sky is not static, but alive with motion, story and transformation.

These rare alignments are the kind of liminal moments that inspire my work as a visual storyteller. Not just because of their beauty, but because of what they stir in us. A double rainbow doesn’t explain itself. Anticrepuscular rays don’t ask for attention. But when we look up and notice, we remember the world is still full of wonder.

Double rainbow

A double rainbow occurs when sunlight is refracted, dispersed, and reflected inside water droplets in the atmosphere. This creates two distinct arcs of colour. The primary rainbow is the brighter and more vivid of the two. Displaying the familiar spectrum of colours from red on the outer edge to violet on the inner edge. The secondary rainbow, which appears outside the primary rainbow is fainter. It’s colours reversed, with red on the inner edge and violet on the outer edge. This phenomenon is caused by a double reflection of sunlight inside the water droplets, resulting in the secondary arc.

Key features of a double rainbow include:

• Primary Rainbow: Bright and vivid, with red on the outer edge and violet on the inner edge.
• Secondary Rainbow: Fainter, with reversed colors, appearing outside the primary rainbow.
• Alexander’s Band: The darker area of sky between the two rainbows, named after Alexander of Aphrodisias, who first described it in the 2nd century.

Anticrepuscular rays

Anticrepuscular rays are a rarer phenomenon that occurs when crepuscular rays (the familiar “God rays” or sunbeams) appear to converge on the opposite horizon from the sun. These rays are caused by the scattering of sunlight by clouds or atmospheric particles, creating parallel beams of light that seem to radiate from the sun. Due to perspective, these rays appear to converge at a point on the horizon directly opposite the sun, known as the antisolar point.

Key features of anticrepuscular rays include:

• Appearance: Parallel beams of light that seem to converge at a point opposite the sun, often creating a dramatic visual effect.
• Timing: Best observed during sunrise or sunset when the sun is low on the horizon, enhancing the contrast between the rays and the surrounding sky.
• Illusion: The convergence of the rays is an optical illusion created by perspective, similar to how parallel train tracks appear to meet in the distance.

Observing the phenomena together

The simultaneous occurrence of a double rainbow and anticrepuscular rays is a rare and enchanting sight. To observe these phenomena together, specific atmospheric conditions must be met.

rain and sunlight

For a double rainbow to form, there must be sunlight shining through raindrops at a low angle. Typically during or after a rain shower.

scattering particles

For anticrepuscular rays, there must be atmospheric particles or clouds to scatter the sunlight. In doing so, these create the parallel beams of light.

perspective

The observer must be positioned in a way that allows viewing of both the double rainbow in the direction of the sun and the anticrepuscular rays on the opposite horizon.

When these conditions align, the result is a breathtaking combination of vivid rainbows and ethereal rays of light converging on the horizon, offering a moment of natural wonder that few get to experience.

Double rainbows and anticrepuscular rays are two awe-inspiring atmospheric phenomena that can occasionally be observed together. A double rainbow consists of two concentric arcs with reversed colors, caused by the refraction and reflection of sunlight in water droplets. Anticrepuscular rays are parallel beams of light that appear to converge at a point opposite the sun, created by the scattering of sunlight by clouds or particles. Observing these phenomena together requires specific atmospheric conditions, resulting in a rare and magical display of nature’s beauty.

Explore more about my love for meteorology, here.