Michael Schneider’s Alpine Halo Photographs and Their Annotated Arcs

Sometimes the most memorable sight on a mountain is above the mountains. In late November 2019, Michael Schneider photographed an elaborate display of rings and bright arcs around the Sun near Arosa, Switzerland. The result looks wonderfully improbable, yet the ingredients were light and tiny ice crystals.

The photographs are a lovely reminder to leave a little space for the unexpected. A ski outing provided the setting; a pause to look at the sky provided the story.

Michael Schneider's November 2019 observation

In his account of the event, Schneider places the scene on the Hörnligrat above Arosa. He was waiting to meet a friend and experimenting with a new smartphone camera as the sunlight changed. His post dates from December 2019, with later updates following the photograph’s wider circulation.

Schneider's account makes the circumstances unusually clear: he was on the Hörnligrat late in November, waiting for a skiing companion while sunshine emerged through the remaining cloud and mist. The camera was a smartphone, but the opportunity came from the weather and the decision to look up. Those ordinary details give an extraordinary photograph a recognisable human setting. ^[1]

How ice crystals shape the light

Halos form when light interacts with ice crystals in the atmosphere. Crystal shape and orientation influence the pattern we see. A familiar example is the 22-degree halo, a ring whose radius is an angle in the sky—not a distance you could measure in kilometres from the observer.

Different effects can appear together, which is why an annotated image may contain several names. The Atmospheric Optics halo collection is useful for comparing forms rather than calling every bright arc a rainbow. Rainbows and ice halos arise from different optical circumstances.

Read the ring, arcs and surrounding landscape

Begin with the horizon. Then follow the visible curves, noting which features form a complete ring and which appear as separate arcs or bright spots. A wider view often makes the arrangement easier to understand than a tightly cropped photograph of the brightest patch.

Keep ordinary sun safety in mind: do not stare at the Sun, and do not point an optical viewfinder or binoculars at it. You can enjoy the surrounding sky while using a building or another solid object to block the solar disc from view.

Enjoy Arosa without depending on a rare display

You can plan a mountain day, but you cannot reserve the necessary crystals, light and viewing angle. Choose Arosa for the activities and scenery you would enjoy anyway. Treat an unusual sky as an extra, rather than the only measure of a successful outing.

Winter photographs become even more rewarding when their context is clear. Our look back at Newfoundland’s 2020 blizzard explores another spectacular set of images and the everyday circumstances behind them.

The Halo Display, Annotated

An annotation by Mark McCaughrean helped viewers distinguish the overlapping forms in Schneider's image, using Atmospheric Optics material as a reference. Keep the unmarked photograph and the annotated version together when studying the display. One preserves the experience of seeing the sky; the other gives names and structure to features that might otherwise merge into a single complicated pattern.

The account identifies a supralateral arc as well as the familiar 22-degree halo. Comparing those labels with the curves is more useful than simply counting circles: some features are partial arcs, and the whole arrangement depends on the observer's view of light passing through differently oriented crystals. Start with the clearest ring, then follow one additional feature at a time. That slower reading turns the photograph from an impressive backdrop into something you can examine, without implying that a phone or a trip to the same mountain will reproduce the display.