Lower Parry arc in Antarctica region

Joe MacGregor observed very rare Lower Parry sunvex arc in Antarctica. Joe say: "The photo was taken about January 19, 2006 somewhere within ~100 km of 79S, 117W. It was taken with a point-and-shoot Canon S230." More photos halos are here. Simulation is made with Halosim by Les Cowley and Michael Schroeder. This Sun display with Lower Parry sunvex arc is probably second case of the World.

Low sun Parry in Helsinki

October is probably the worst halo month in Finland. The last chances for good high cloud displays are gone with September and diamond dust is not swarming in until November. So it was nice to see today a low sun Parry starting to develop in the sky upon returning from grocery store. Grabbed pocket camera and tripod from my room and rushed to nearby parking lot.

The two images are stacked from series of 15 and 16 shots. The time span is two minutes in both stacks.

Earlier I had seen low sun Parry's only on two occasions. These were in high arctic Canada during diamond dust conditions. It took 22 years of observing to get one in high clouds.

Wegener arcs in Czechoslovakia again

Today (9:00 - 11:30 UT) was next nice day. Sky in Holesov showed clear and coloured Wegener arc and other arcs (common halos and upper Parry suncave arc, lower Lowitz arc and infralateral arc).

Display was photographed also by others. Here are the photos by Martin Jankovic from Brno.

[text: Patrik Trncak]

From archives: odd radius column arcs in 2001

I saw this display in Oulu on 17 September 2001. Because the photos have not been around in the internet, I dare to make posting even though the event is not so recent.

The display has all the odd radius column arcs except the 23° arc. Images are stacked from 3-8 individual images. The one on the lower right is also flipped horizontally to get a bit more definition. For the upper left and lower images, simulations of the pyramid column arcs give crystals as in the figure. Also shown is similarly shaped real crystal, photographed during a weak odd radius column arc display at South Pole in 1999.

From pyramid plate crystals there is the 23° plate arc in all photos, and lower 9° and 24° plate arcs in the upper right photo. The display was discussed in more detail in September 2003 number of journal Weather. It also appears in the book "Atmospheric halos and the search for angle x" by Tape and Moilanen.

Lowitz arcs in Czech

Martin Popek observed this display with Lowitz acrs on 16. September. Interesting feature is the lower Lowitz component extension above parhelion. In the simulation there is something like that, but it's very, very ghostly. The main body of the lower component below parhelion looks as if it were just a patch of 22° halo - the extension towards parhelion is missing. Same goes with the upper component. This is quite typical way of Lowitz arcs showing up. Circular component is seen only above parhelion.

I was given sun elevation of 39° for this display but somewhat lower elevation gave a bit better simulation results. This is for 33°. The projection in the simulation is clearly not the same as in camera and this may have caused some of the broblems. Simulation is made with Halosim by Les Cowley and Michael Schroeder.

Be the sun elevation 39° or 33°, it does not change much anything fundamentally. Several question could be raised about this display with lenghty discussions. It seems we still have a long way to understanding Lowitz arcs.

V-shaped Parry and Tape's arc in Germany

On August 31, 2006, clouds moved in destroying all hopes for meteor observations in the night. The halo display in the high clouds close to sunset (1725 UT, Sun elevation approximately 3 deg) observed by Jürgen Rendtel from Marquardt (west of Berlin, 13.0 deg E, 52.5 deg N) included intense V-shaped upper tangent and Parry arcs. Another bright coloured 'spot' of about 3 deg apparent size was found to be part of the supralateral arc and Tape's halo. The image processing by Claudia Hinz using unsharp masking also revealed the convex Parry arc.

Circumscribed halo and pyramid halos in Sardinia

This display was captured by Jan Drahokoupil in Sardinia on 6. September. The 22° halo is surrounded by elliptical circumscribed halo. The small halo around the sun is 9° halo or 9° column arc (or both together). Simulations could give better clue. Later on the display changed and there were also 18° plate arcs.

More photos here.