Today's Feature Sun Pillars

Last updated on September 16, 2023

Today's Feature Sun Pillars: A Delicate and Subtle Atmospheric Phenomenon

Sun pillars, also known as light pillars, are a captivating atmospheric optical phenomenon that occurs during sunset. These mesmerizing vertical shafts of light can be observed slowly creeping along the horizon, always positioned directly above the hidden sun. While some sun pillars are more pronounced and easily visible, it is often the delicate and subtle ones that offer the most exquisite display.

What appears to be a vertical beam of light is actually the result of countless ice crystals reflecting sunlight towards the observer's eye. These ice crystals, ranging from flat plates to column-like structures, are typically found in high-altitude clouds. In exceptionally cold weather conditions, they can even manifest as "diamond dust" near the Earth's surface.

To witness the enchanting sight of sun pillars, one should look towards the horizon after sunset. These optical phenomena can persist for up to an hour, gradually shifting their position along with the setting sun. The precise alignment between the sun, ice crystals, and the observer's vantage point creates an awe-inspiring visual spectacle.

Here are some fascinating details about sun pillars that further illuminate their captivating nature:

1. Formation: Sun pillars form when sunlight interacts with horizontally oriented ice crystals suspended in the atmosphere. As light passes through these ice crystals, it undergoes a process called refraction, bending the light rays and causing them to scatter vertically.

2. Ice Crystal Shape: The shape and orientation of the ice crystals play a crucial role in determining the appearance of sun pillars. Flat, plate-like crystals tend to produce distinct pillar-like shapes, while columnar crystals may result in more elongated or distorted pillars.

3. Atmospheric Conditions: Sun pillars are more likely to occur in regions experiencing very cold temperatures, where ice crystals can form and remain suspended in the air. Additionally, high-altitude clouds, such as cirrus clouds, often harbor the necessary ice crystals for sun pillar formation.

4. Colors: Sun pillars can exhibit a range of colors, including vibrant shades of red, orange, yellow, and even purple. These colors arise from the scattering of sunlight by the ice crystals, with shorter wavelengths being scattered more than longer ones.

5. Pillar Height: The height of sun pillars can vary depending on the altitude at which the ice crystals are located. In some cases, these pillars can extend several degrees above the horizon, creating a striking vertical presence in the sky.

6. Variations: While the classic sun pillar appears as a vertical beam of light, variations of this phenomenon can also occur. For example, multiple pillars may form simultaneously, creating a mesmerizing display of parallel shafts of light stretching across the horizon.

7. Photographing Sun Pillars: Capturing the beauty of sun pillars in photographs requires patience and careful observation. Adjusting camera settings to capture the subtle details of the phenomenon, such as using a longer exposure time, can enhance the visibility and vibrancy of the pillars.

8. Scientific Importance: Sun pillars are not only visually stunning but also hold scientific significance. Studying these optical phenomena helps researchers gain insights into atmospheric conditions, such as ice crystal distribution and composition, which contribute to our understanding of weather patterns and climate dynamics.

9. Similar Phenomena: Sun pillars are part of a broader family of atmospheric optical phenomena known as halos. Other members of this family include sun dogs, circumzenithal arcs, and lunar halos. These related phenomena are all formed by the interaction of sunlight with ice crystals or water droplets in the atmosphere.

10. Global Occurrence: Sun pillars can be observed in various parts of the world, provided the necessary atmospheric conditions are met. Regions with cold climates and frequent high-altitude cloud cover offer more opportunities for witnessing these captivating displays of light.

The delicate beauty of sun pillars serves as a reminder of the remarkable interactions between sunlight, ice crystals, and our atmosphere. Whether observed in person or captured through photography, these optical phenomena continue to captivate and inspire awe in all who witness them.

Sunset Pillar

Imaged at Ronse, Belgium by Michel Vandeputte.

Look for pillars after sunset. Sometimes they can be seen for up to an hour slowly creeping along the horizon and always exactly above the hidden sun. The delicate and subtle ones are often the finest.

They look like vertical shafts of light but they are actually the glints of untold millions of ice crystals reflecting the sun towards the eye. The crystals, flat plates and sometimes columns, are here in high clouds. In very cold weather they can be 'diamond dust' near ground level.

Image ©Michel Vandeputte, shown with permission.

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!