Last month I wrote about Bill Beaty’s “Leaping Sundogs”, with a couple of fascinating videos recording the dancing streamers of light.

Now, new hi-def videos have just been published on Youtube. User “abrigatti” wrote:

“I was pool side in my apartment in Singapore, when I saw something weird in the skies. As I looked over head I saw some weird cloud shoots of light and puff as the clouds seemed to reform sporadically. I could see that a storm cloud was building, but the light and visual show was intriguing me. So I grabbed my iPhone and recorded this.”

Recorded on August 14th, abrigatti also posted a second video:

Beaty had already updated his page with new speculations, and meanwhile, I also received comments from fellows Martin Shough and Wim Van Utrecht.

Shough notes that Beaty’s suggestion of ice crystals re-alignment due to electrical storms was considered during a 1999 conference on sprites, as it seems the phenomenon may have been observed by satellites! And there’s more…

From chapter 10 of FMA Research, Fort Collins, Colorado:

“Some US satellites carry transient radiometric sensors capable of recording atmospheric visible-light flashes such as lightning and bright meteors (Tagliaferri, 1994). On 18 September, 1999, within a span of about 30 minutes, a sequence of seven visible-light flash events were detected by non-imaging transient radiometers aboard two geostationary satellites. Associated with three of these events were distinct shifts in the level of total background light from the earth received at each satellite. A consistent pattern, in which the satellite to the west of the event recorded an increase while the one to the east recorded a decrease, was observed. Changes in background level did not occur abruptly, but took place over a span of approximately one-half second, with onsets preceding the flashes by a quarter-second or less. Since these anomalous observations were not understood and were apparently associated with lightning from a mesoscale convective system (MCS), we held a DOE workshop on the topic in Albuquerque on 16 November 1999 to explore possible explanations. We considered a number of possible explanations but settled on a single viable explanation based on known physical properties of changes in solar reflectivity due to re-alignment of ice crystals as a result of the charge dynamics associated with large positive lightning events.

…

"During the discussion of these possibilities, it was suggested (by Mark Stanley, NMT), as mentioned in V.3.3 above, that the nature of the reflectivity of clouds can change as a result of the alignment of ice crystals. The alignment (or randomization) of the crystals is easily influenced by changes in electric and magnetic fields. In fact, this observation has been demonstrated many times under laboratory conditions. We coupled this information with the following observations to arrive at what we believe to be the most probable explanation of the satellite observations.”

Not only that, Utrecht also found on William Corliss’ treasure trove some references to the phenomenon recorded in decades past:

“In "Lightning, Auroras,…" there’s a Chapter called "Crown Flash" which is described as "The brightening of a thunderhead crown followed by the appearance of aurora-like streamers emanating into the clear atmosphere. Crown flash seems to be synchronized with lightning strokes from the cloud base to the ground" (although the latter synchronicity is not really that evident from the three examples CORLISS cites). I quote: [X1. July 2, 1970, Ann Arbor, Michigan. While observing a thundercloud. "At and just above the peak of the storm cell the cloud mass seemed to be undergoing sudden changes in brightness lasting for several seconds at a time…. The phenomenon continued to occur repeatedly at intervals of 30-60 s during the next 15 or 20 min, providing the basis for the following description. The sudden brightening effect began

concurrently with lightning strokes in the main cloud mass, but continued after the lightning flash was over. It had the appearance of a ripple-like upward and outward spread of radiance from the region just west of the peak of the cumulus cloud, resembling somewhat a fan-like display of aurora borealis. It lasted a substantial fraction of a second with each lightning stroke. On one or two occasions it had the appearance of a bright ring moving rapidly outward and upward above the cumulus peak. On these occasions it was clearly observed to extend beyond the cloud and into the blue sky. A linear shadow, apparently cast by one of the cumulus masses, appared to shift its position suddenly up or down with each occurence of the event."

X2. August 18, 1950. St. Albans, England. "At 12.25 GMT a cumulo-nimbus of moderate size was passing about four miles to the south, and giving rumbles of thunder about once every minute. While observing the cloud my attention was drawn to a bright streamer, apparently of cloud, projecting northwards from the anvil top for a distance of five degrees. As I watched, the streamer suddenly ‘exploded’ into a rapidly widening circle of light, fading as it did so. Immediately afterwards the streamer started to reform in the same place as before, only to repeat its ‘disappearing’ act again after a minute or so, presumably whenever an electrical discharge took place. On some occasions the streamer shifted violently to one side, changing its form greatly, but always returning to one spot. The spectacle lasted for half an hour, becoming fainter as the cloud moved away eastward."

X3. April 30, 1885. Denison, Texas. A glowing region repeatedly travels along the tops of thunderclouds that were arranged in a long bank.

References

R1. Gall, John C., jun., and Graves, Maurice E.; "Possible Newly Recognized Meteorological Phenomenon Called Crown Flash," Nature, 229:185, 1971. (X1)

R2. Hale, R.B.; "Unusual Lightning," Weather, 5:394, 1950. (X2)

R3. "Electrical Phenomena," Monthly Weather Review, 13:103, 1885. (X3)] In "Rare Halos, Mirages…" there’s a Chapter that may be of interest too. It’s called "Jumping and Moving Halos". Sounds promising, but all entries here relate to moon halos, except this one (which reminds of what can be seen in the "big leap" video on Bill BEATY’s site): [X3. April 30, 1977. Manitoba, Canada.

"…at 1358 Central Standard Time plus an hour of daylight saving time I was attempting to observe the sun. Conditions were very violent with evidence of cross currents in cumulonimbus between the cumulus itself and the glaciated upper portions. As conditions deteriorated I looked up to ascertain what my chances of further solar observations might be. The cumulonimbus were moving from west to east and the glaciated tops from north to south. In the glaciated sheet a weakly coloured halo was visible. Using a home-made theodolite I undertook a routine measurement of the angular radius of the halo. To my surprise the value was 15 degrees from the sun to the inner edge of the halo with about a half degree spread of the spectrum, blue to the outside and red to the inside. I checked the instrument and made a second measurement, having doubted my first. This confirmed my first observation but, still not sure, I attempted a third measurement. Whilst making this I saw the halo jump to a radius of 22 degrees. The jump was over a period of

seconds only. The 15-degree halo faded quickly and a 22-degree halo replaced it."]

The reference for this entry is:

[R3. Wadsworth, D.J.; "Solar Halo of 15 Degrees—30 April 1977," Weather, 33:113, 1978. (X3)]”

I think the most relevant reference is the 1971 letter to Nature (X1,R1) by Gall and Graves, from University of Michigan, which seems to be exactly what these recent Youtube videos record. And if they are, well, they’ve got a name: Crown Flash.

[With many thanks to Bill Beaty, Martin Shough and Wim Van Utrecht. Sadly, William R. Corliss passed away last month]

Popularity: 4% [?]

Posted in Fortean