Digging for Halos

Last updated on September 16, 2023

Digging for Halos: A Mesmerizing Atmospheric Phenomenon

Have you ever witnessed a mesmerizing display of light pillars piercing the night sky? These ethereal columns of light, known as halos, can be a breathtaking sight to behold. In this article, we will delve into the captivating world of halos, exploring their origins, characteristics, and the fascinating science behind them.

The Enigmatic Beauty of Halo Hunting

Picture yourself in the frosty landscapes of Finland, surrounded by temperatures as low as -24°C. It is here that two intrepid halo hunters, Jari Luomanen and Marko Riikonen, embarked on a quest to capture the elusive beauty of halos. Armed with their cameras and a keen eye for atmospheric optics, they set out to document this ethereal phenomenon.

Pillars of Light: Illusions in the Sky

As Jari and Marko observed, the pillars of light that compose a halo are not tangible structures reaching towards the heavens. Instead, they are optical illusions created by the reflection of ground lights off countless ice crystals suspended in the air. These ice crystals, situated approximately halfway between the light source and the camera, act as tiny mirrors, bending and dispersing the light to form the vertical columns we perceive as halos.

The Intricacies of Halo Formation

Halos come in various forms and can manifest themselves in different ways depending on atmospheric conditions and the type of ice crystals present. The crystal swarm responsible for these captivating displays often consists of plate-shaped ice crystals. This is evident from the absence of column crystal arcs near the light sources themselves.

The Dance of Light: Stratified Crystal Layers

One intriguing aspect observed by Jari and Marko was the stratification of the crystal swarm into distinct layers. These layers manifested as discontinuous shafts of light, adding a touch of complexity to the already enchanting spectacle. The intensity of the pillars was staggering at times, with the colors faithfully reflecting the original light source on the ground. It is worth noting that different types of bulbs can produce varying hues in the resulting halos.

Exploring the Science Behind Halos

To truly appreciate the magic of halos, it is essential to understand the scientific principles at play. The formation of halos relies on two key factors: the presence of ice crystals suspended in the atmosphere and the angle at which light interacts with these crystals. When light passes through or reflects off these ice crystals, it undergoes refraction, dispersion, and reflection, leading to the creation of the intricate patterns we observe as halos.

The Diversity of Halo Types

Halos come in a wide array of shapes and sizes, each with its own unique characteristics. Some of the most common types include:

• Circumhorizontal Arcs: These arcs, also known as fire rainbows, form when sunlight passes through ice crystals in high-altitude cirrus clouds, resulting in a stunning display of vibrant colors.
• Circumscribed Halos: These halos appear as bright rings encircling the sun or moon. They are caused by the refraction and reflection of light within hexagonal ice crystals.
• Supralateral Arcs: These arcs, which resemble inverted rainbows, occur when light is refracted and reflected within plate-shaped ice crystals.
• Tangent Arcs: These arcs are characterized by their close proximity to a halo's main circle. They are formed when light is refracted and reflected within horizontally oriented ice crystals.

Capturing the Magic: Photographing Halos

Thanks to the dedication and expertise of halo hunters like Jari Luomanen and Marko Riikonen, we are able to witness and appreciate the enchanting beauty of halos captured through photography. Through their lens, we gain a deeper understanding of the intricate details and nuances present in these celestial phenomena.

The Quest Continues: Unraveling Halo Mysteries

While much is known about halos, there is still much to discover and unravel about these captivating atmospheric optics phenomena. Scientists and enthusiasts alike continue to explore the complexities of halo formation, seeking to uncover the secrets behind their mesmerizing displays.

Embrace the Wonder of Halos

Next time you find yourself gazing at the night sky or marveling at the vibrant hues of a halo, take a moment to appreciate the intricate dance of light and ice crystals occurring above. Halos remind us of the beauty and complexity of our natural world, inviting us to explore and understand the mysteries that lie just beyond our reach.

Digging for Halos, Finland

Imaged by Jari Luomanen (site) and Marko Riikonen (site) during a halo hunting session in temperatures of -24C on the night of January 2/3. Local lights are each topped by an intense and incredibly narrow coloured light pillar. Images �Jari Luomanen & Marko Riikonen as marked.

Marko: "We had been driving around in the industrial area of Tampere for some while and Jari suggested we take a little break somewhere. For the location I suggested the place with excavators that we had driven past a couple of times. In case the crystal swarm intensifies we could get nice photos there. And that's what happened."

Jari: "The pillars were possibly the sharpest that I have observed. At times they exhibited staggering intensity. Furthermore, the crystal swarm was stratified into various layers and these manifested themselves as discontinuous shafts of light. Note that the pillars faithfully reflect the colour of the original light source on the ground: various bulbs give different colours."

The pillars of light are of course an illusion. In reality there are no upward shafts of light. Instead they are the reflections of the ground lights by millions of ice crystals roughly half-way between the light and the camera. The crystals making this display were plates as evidenced by the absence of column crystal arcs near the lights themselves.

More of Marko's and Jari's images.

Note: this article has been automatically converted from the old site and may not appear as intended. You can find the original article here.

Reference Atmospheric Optics

If you use any of the definitions, information, or data presented on Atmospheric Optics, please copy the link or reference below to properly credit us as the reference source. Thank you!