around the antisolar point.
An amazingly bright and rare display seen by Virginia meteorologist
Jacob Klee on a flight from Cincinnati to Richmond Virginia during
the afternoon of 12th November 2000.
The camera points downwards. The horizon is hidden by the cirrus haze
in the topmost quarter of the image.
The antisolar point, the point diametrically opposite the sun,
is at the bright diamond with the aircraft's shadow in its centre.
The horizontal halo passing through the antisolar point is a bright
The diagonal cross is a combination of diffuse arcs from horizontal
column crystals and an antisolar arc from Parry oriented columns.
The arcs are labeled in the simulation below.
for the solar elevation of 13.5° estimated from the flight times and
fits to the photograph. The imaged area is within the blue rectangle.
The Parry antisolar arc extends upwards from the antisolar point to
form the two outermost parts of the diagonal cross.
The subhorizon arcs in the antisolar region are much narrower than
their above horizon counterparts and remain narrow even when the crystal
tilts are quite large.
The simulation used 70% singly oriented column crystals, 15% Parry
oriented columns and 15% horizontal plates. The columns had c/a ratios
of 1-3 and tilts from 0.5 to 5°.