Here is listed all known halos. The word "known" means here that halos has been documented by photographs. So all of these halos does exist in
nature. Common halos are marked by using bold text.
List of common (frequently observed) halos
- 22° halo
- (22°) parhelia
- (22°) tangent arcs
- upper tangent arc
- lower tangent arc
- circumscribed halo
- 46° plate arcs
- circumzenith arc
- circumhorizon arc
- 46° halo
- 46° column arcs
- (46°) infralateral arcs
- (46°) supralateral arc
- parhelic circle
- sun pillar
- subsun
Here you can find rules, which define
list of common halos.
All halos by origin
Probably the easiest way to learn halos is to learn how they form.
There is several halos which has more than one name used in literature.
Origin of halos also tells you halo families. If you see parhelia, you
have good possibility to see circumzenithal arc, since they form from
the same orientation and ice crystal.
Halos from randomly oriented ice crystals
Halos from (single) oriented columns
- sun pillar
- (22°) tangent arcs
- upper tangent arc
- lower tangent arc
- circumscribed halo
- parhelic circle
- 46° column arcs
- (46°) supralateral arc
- (46°) infralateral arcs
- Wegener arc (=Wegener anthelic arc)
- Greenler arcs (= diffuse arcs / diffuse anthelic arcs)
- diffuse anthelic arcs A
- diffuse anthelic arcs B
- anthelion (for historical reasons anthelion is counted as an individual halo)
- Tricker arc (= Tricker anthelic arc)
- subheliac arc
Halos from oriented plates
- sun pillar
- (22°) parhelia
- 46° plate arcs
- circumzenith arc
- circumhorizon arc
- parhelic circle
- subsun
- 120° parhelia
- Liljequist parhelia
- subparhelia
- subparhelic circle
- Liljequist subparhelia
- superparhelia (artificial light source halo)
- "upper subsun pillar" (artificial light source halo)
Plate arcs from multiple scattering (= halos from plate
oriented ice crystals)
Multiple scattering means that after leaving an ice crystal ray path
will hit other ice crystals before entering into observers eyes.
Halos from Lowitz-oriented plates
- Lowitz arcs
- lower Lowitz arc (A Lowitz)
- upper Lowitz arc (B Lowitz)
- circular Lowitz arc (C Lowitz)
- Reflected Lowitz arcs (sub-Lowitz arcs)
- reflected Lowitz arcs A
- reflected Lowitz arcs B
- reflected Lowitz arcs C
- 120° Lowitz arcs (=120° parhelic arcs)
- 120° Lowitz arc A ("rising")
- 120° Lowitz arc B ("diving")
- 46° Lowitz arcs (= 46° contact arcs)
- 46° upmost Lowitz arcs or "Galle arc"
- 46° upper surpalateral Lowitz arcs
Halos from Parry oriented columns
- (22°) Parry arcs
- (upper suncave) Parry arc
- upper sunvex Parry arc
- lower suncave Parry arc
- lower sunvex Parry arc
- 46° Parry arcs
- circumzenith arc (= 46° symmetrical Parry arc)1
- upper Tape arcs (= 46° Parry supralateral arcs)
- lower Tape arcs (= 46° Parry infralateral arcs)
- Hastings arc (= Hastings anthelic arc)
- Tricker arc (= Tricker anthelic arc) 2
- heliac arc
- subheliac arc
- subantheliac arc (= antisolar arc)
1) Some common halos (circumzenith arc, parhelic circle and
subsun) can also be produced by Parry oriented columns, but their Parry variations are rare and usually
superimposed by the same halos from plate orientation. Convincing identification for Parry variations of
these halos is usually impossible to obtain and they are not listed
here. However, circumzenith arc is listed, since it is acompanied by
additional arcs only possible from Parry orientation.
2) Tricker arc is formed also by single
oriented columns.
Circular odd radius halos (=halos from randomly oriented
pyramid ice crystals)
All halos and arcs associated with halos, which are produced by
pyramid ice crystals are usually called as odd radius halos.
- 9° halo (= van Buijsen's halo)
- 18° halo (= Rankin's halo)
- 20° halo (= Burney's halo)
- 23° halo (= Barkow's halo)
- 24° halo (= Dutheil's halo)
- 35° halo (= Feuillée's halo)
Odd radius plate arcs (= halos from oriented pyramidal plate ice crystals)
- 9° parhelia (= 9° plate arcs)
- 9° lower parhelion (= 9° lower plate arc)
- 9° upper parhelion (= 9° upper plate arc)
- 18° parhelia (= 18° plate arcs)
- 20° parhelia (= 20° plate arcs)
- 20° lower parhelion (= 20° lower plate arc)
- 20° upper parhelion (= 20° upper plate arc)
- 23° parhelia (= 23° plate arcs)
- 23° lower parhelion (= 23° lower plate arc)
- 23° upper parhelion (= 23° upper plate arc)
- 24° parhelia (= 24° plate arcs)
- 24° lower parhelia (= 24° lower plate arcs)
- 24° upper parhelia (= 24° upper plate arcs)
- 35° parhelia (= 35° plate arcs)
- 35° lower parhelia (= 35° lower plate arcs)
- 35° upper parhelia (= 35° upper plate arcs)
- odd radius heliac arc (= pyramidal heliac arc)
Odd radius column arcs (= halos from column oriented pyramidal ice crystals)
- 9° tangent arcs (= 9° column arcs)
- 9° lower tangent arcs (= 9° lower column arcs)
- 9° upper tangent arcs (= 9° upper column arcs)
- 18° tangent arcs (= 18° column arcs)
- 18° upper tangent arcs (= 18° upper column arcs)
- 20° tangent arcs (= 20° column arcs)
- 24° tangent arcs (= 24° column arcs)
- 24° upper tangent arcs (= 24° upper column arcs)
- 35° tangent arcs (= 35° column arcs)
- 35° upper tangent arcs (= 35° upper column arcs)
Here I have used name tangent arcs, because they are rising from similar ice crystal orientations than 22° tangent arcs and are usually seen with them.
There should be 23° tangent arcs too, but they are not photographed
yet.
Odd radius Parry arcs (= halos from Parry oriented pyramidal ice crystals)
All halos from Parry oriented pyramidal column ice crystals are
theoretical, since there is no known observations of them - yet.
Halos without confirmed explanations
There is many halos which origin is not yet known for sure. Here I
have divide these in three categories.
Elliptical halos (from untypical ice crystals)
- elliptical halos
- 1x ellipse
- 2x ellipses
- 3x ellipses
- 4x ellipses
- Bottlinger's rings
- 1x Bottlinger's ring
- 2x Bottlinger's rings
I have divide these according to number of different sized halos in
the same display. So 1x means
1 ellipse, 2x means two ellipses etc.
"Untypical" here means that these can not be explained
with normal hexagonal ice crystals or with pyramid ice crystal which
pyramidal ends have commonly used 56.142° apex angle, e.g. with
{101-1} crystallographic faces. There is no widely accepted theory of origin of elliptical halos.
Lascar display halos (= halos from cubic ice crystals?)
- 19° arcs
- 19° lateral arcs
- 19° lower arc
- 19° upper arc
- 28° halo
- Lascar arcs (28° arcs)
- upper tangent Lascar arc A
- lower tangent Lascar arc
- supralateral Lascar arcs
- infralateral Lascar arcs
- 28° parhelia
A cubic ice crystals has been suggested to explain a display photographed in Chile 1997. This explanation is not fully
confirmed and it has some weaknesses, but it seems to be the best explanation found so
far. This display was an unique and similar display is never described in halo literature.
One thing seems quite obvious: a typical hexagonal ice crystal does not
produce these observed and photographed halos.
28° halo has been often called as "Scheiner's halo", but
because it is not clear what Scheiner really saw, I do not use that
name here.
Unexplained halos
- Moilanen arc (= M-arc)
- 5° halo (= 6° halo)
- 12° halo
- Parhelia flares
All of these has been photographed, but the correct explanations
are still missing.
For Moilanen arc orientation of ice crystal wedge is
known, but the actual shape of the ice crystal is not known.
For 5° and 12° halos (both were photographed at the same display
at the South Pole 10-11. Dec 1998) there is a couple of quite promising theories, which are not fully
matching.
Parhelia flares are very similar than Lowitz arcs or reflected
Lowitz arcs, but photographs of parhelic flares can not be explain
with them.
Special effects of halos
- parhelia legs (usually missidentified as Lowitz arcs)
- blue spot on parhelic circle (behind 120° parhelia)
- 120° parhelic pillar
- intersection of 22° halo on ground (artificial light source halos
only)
These are effects on halos and they are not individual halo forms.
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