I just wanted to write to tell you that I did observe this phenomenon that your case example describes. I saw it earlier than when the photo was taken when the lights were still circular and "fuzzy" or "hazy" in appearance. They did have a greenish tint to them to the naked eye. Your ice crystal explanation sounds plausible, but why is it that this has not been observed before or since? The runway lights are on all night, and I am sure that the conditions to produce this effect happen often. I did not attempt to take any photos, my small camera would not have produced any quality photos for study.
Keep looking up!
[Mrs. DUTTON is the spouse of an active duty Air Force member who worked at Ramstein Air Base at the time of the incident. She observed the lights right outside their place of residence, which was in base housing, approximately 1-2 miles from the flightline/runway. In a second mail, dated December 19, Mrs. DUTTON specified that the lights were almost directly above her and appeared as "seven greenish orbs in a straight line". Although she was thinking about reflections, Mrs. DUTTON thought it strange that she could not see any clouds in the sky to reflect from.]
Our reply :
We are very grateful to Mrs. DUTTON for sharing with us her personal observation.
The reason why reflections have not been observed at Ramstein AB before could be twofold:
Not only are we dealing with a rare phenomenon (what you need is billions of ice crystals oscillating in a horizontal plane with clean, flat sides large enough to reflect the light), there is also the fact that people almost never look up at a point in the sky high above them. Actually, the best chance for someone to spot a reflection of these runway lights would be many miles away from the base and with the reflective cloud layer positioned somewhere halfway in between the point of observation and the lights. In those conditions, the mirrored images will appear as a series of parallel streaks close to the horizon, much easier to detect than when they are located near the zenith. Also, an observer many miles away from the base, would not be apt to link the light pillars to the runway lights since these would be invisible to him at that distance. In short, the runway lights may have caused similar reflections on other occasions but may not have been identified as such.
As for the apparent absence of clouds, this is fairly typical for light pillar displays. It is one of the reasons why the pillars are often attributed to a non-meteorological cause. The ice-crystal clouds that produce the mirrored images are almost always transparent, which is also illustrated by the fact that stars are visible in most of the light pillar photos we collected.