TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 DEF

A halo phenomenon consisting of a coloured arc, red on its upper margin; it extends for about 90° parallel to the horizon and lies about 46° below the Sun [or Moon].  2, record 1, English, - circumhorizontal%20arc

Record number: 1, Textual support number: 1 OBS

It is produced by the refraction of light through the 90° prisms of ice crystals, having entered through the vertical sides and passing out through the horizontal bases. Normally, the crystals are large, oriented, hexagonal plates. The circumhorizontal arc is the low sky counterpart of circumzenithal arc. The circumhorizontal arc is low in the sky when the sun is high (above 58° elevation); the circumzenithal arc is high in the sky when the sun is low (below 32° elevation). The most colorful circumhorizontal arcs occur when the refraction is close to the minimum angle of deviation, and this corresponds to a solar elevation angle of about 68°. In the midlatitudes, the sun only climbs to that elevation for a few hours mid day around the summer solstice.  3, record 1, English, - circumhorizontal%20arc

Record 1,  Textual support,  French

Record number: 1, Textual support number: 1 DEF

Phénomène de halo consistant en un arc coloré, rouge à son extrémité supérieure; il s'étend sur environ 90° parallèlement à l'horizon, à 46° au-dessous du Soleil.  2, record 1, French, - arc%20circumhorizontal

Record number: 1, Textual support number: 1 CONT

Quand le Soleil est assez haut dans le ciel (de 32° à 90° de hauteur de l'horizon) un arc circumhorizontal peut être visible sous le Soleil près de l'horizon lors de passage de cirrus. Ces arcs ont la forme inverse à l'arc circumzénithal, sont assez grands et sont produits par les cristaux plats. Ces arcs sont parmi les moins visibles. [...] Plus on est en basse latitude plus on a la chance de [les] voir [...] Ils ne peuvent pas être visibles quand on monte au-delà de 55° de latitude [...] Vers le nord de la France ou en Allemagne à 50° de latitude, l'arc circumhorizontal n'est visible qu'une fois en été [...] C'est un des [...] arcs à ne pas être visible partout sur Terre.  3, record 1, French, - arc%20circumhorizontal

Record 1,  Textual support,  Spanish

Record number: 1, Textual support number: 1 DEF

Halo que consta de un arco coloreado con el rojo en su lado superior. Este arco se extiende alrededor de 90° paralelo al horizonte en una altura de aproximadamente 46° por debajo del Sol.  1, record 1, Spanish, - arco%20circumhorizontal

Record 2,  Textual support,  English

Record number: 2, Textual support number: 1 DEF

Halo phenomenon produced by reflection of sunlight on ice crystals in certain clouds.  2, record 2, English, - undersun

Record number: 2, Textual support number: 1 OBS

It appears vertically below the Sun in the form of a brilliant white spot, similar to the image of the Sun on a calm water surface. It is necessary to look downward to see the phenomenon which is, therefore, only observed from an aircraft or from a high elevation.  2, record 2, English, - undersun

Record 2,  Textual support,  French

Record number: 2, Textual support number: 1 DEF

Phénomène de halo engendré par la réflexion de la lumière solaire sur les cristaux de glace de certains nuages.  2, record 2, French, - pseudoh%C3%A9lie

Record number: 2, Textual support number: 1 OBS

Il apparaît à la verticale et au-dessous du Soleil sous forme d'une tache blanche et brillante semblable à l'image du Soleil sur une étendue d'eau calme. Pour le voir, on doit regarder vers le bas; ce phénomène ne peut, par conséquent, être observé que d'un aéronef ou d'un lieu élevé.  2, record 2, French, - pseudoh%C3%A9lie

Record 2,  Textual support,  Spanish

Record number: 2, Textual support number: 1 DEF

Fenómeno de la familia de los halos producido por la reflexión de la luz solar en los cristales de hielo de ciertas nubes.  1, record 2, Spanish, - pseudohelio

Record number: 2, Textual support number: 1 OBS

Aparece en la vertical por debajo del Sol como una mancha brillante y blanca, semejante a la imagen del Sol en una superficie de agua en calma. Es necesario mirar hacia abajo para ver el pseudohelio; por lo tanto, este fenómeno sólo puede observarse desde aeronaves o lugares altos.  1, record 2, Spanish, - pseudohelio

Record 3,  Textual support,  English

Record number: 3, Textual support number: 1 CONT

The above photo shows a halo phenomenon known as the upper tangent arc. When cirrus clouds contain columnar ice crystals aligned so that their axes are all in a horizontal direction, this type of arc may be produced. A characteristic of this arc-shaped patch of light is that it's directly above the Sun(it bends upward away from the Sun), and it's approximately 22 degrees away from the Sun itself-about 2 fists held at arms length.  1, record 3, English, - upper%20tangent%20arc

Record number: 3, Textual support number: 2 CONT

The 22° halo is most common, but other halo forms are sometimes seen. The tangent arcs to the 22° halo can appear if the sun’s declination is less than 32°. One is called the lower tangent arc to the 22° halo, and the other is the upper tangent arc to the 22° halo. The shape of these tangent haloes depends upon the sun’s declination. If the sun is close to the horizon, the two upper arcs angle sharply away from the 22° halo. As the sun rises higher in the sky, the tangent arcs move toward the 22° halo. When the sun’s declination reaches 32°above the horizon, the lower and upper tangent arcs make contact, and the resulting ring is called the circumscribed halo. It touches the 22° halo above and beneath the sun. When the sun is just above 32°the circumscribed halo resembles a double oval. As the sun rises higher it becomes increasingly circular and draws nearer to the 22° halo. When the sun’s declination exceeds 70°, the circumscribed arc nearly coincides with the 22° halo.  2, record 3, English, - upper%20tangent%20arc

Record 3,  Textual support,  French

Record number: 3, Textual support number: 1 CONT

Un peu au-dessus ou au-dessous de l'astre lumineux [soleil], à la distance de 22 degrés, on peut fréquemment voir des arcs supérieurs et inférieurs tangents au petit anneau. En fait, on observe plus souvent les arcs supérieurs; ils ont souvent de belles couleurs. [...] Sur l'image suivante, on voit un arc tangent supérieur.  2, record 3, French, - arc%20tangent%20sup%C3%A9rieur

Record 3,  Textual support,  Spanish

Record 4,  Textual support,  English

Record number: 4, Textual support number: 1 DEF

Interference pattern produced within the geometrical shadow thrown by an obstacle, due to the bending (by an amount which varies with wavelength) of light waves by the obstacle.  2, record 4, English, - diffraction%20phenomenon

Record number: 4, Textual support number: 1 CONT

... a halo is a refraction/dispersion phenomenon while a glory is a diffraction phenomenon.  3, record 4, English, - diffraction%20phenomenon

Record number: 4, Textual support number: 1 OBS

The most important diffraction phenomena are the aureole, Bishop’s ring, corona and glory.  2, record 4, English, - diffraction%20phenomenon

Record 4,  Textual support,  French

Record number: 4, Textual support number: 1 DEF

Diagramme d'interférences produit dans l'ombre géométrique créée par un obstacle, due à la déflexion (variable selon la longueur d'onde) des ondes lumineuses par l'obstacle.  2, record 4, French, - ph%C3%A9nom%C3%A8ne%20de%20diffraction

Record number: 4, Textual support number: 1 OBS

Les phénomènes de diffraction les plus importants sont : l'auréole, l'anneau de Bishop, la couronne et la gloire.  2, record 4, French, - ph%C3%A9nom%C3%A8ne%20de%20diffraction

Record 4,  Textual support,  Spanish

Record number: 4, Textual support number: 1 DEF

Figura de interferencia producida dentro de la sombra geométrica de un obstáculo por la curvatura, que depende de la longitud de onda de las ondas luminosas que inciden sobre dicho obstáculo.  1, record 4, Spanish, - fen%C3%B3meno%20de%20difracci%C3%B3n

Record number: 4, Textual support number: 1 OBS

Los fenómenos de difracción más importantes son: la aureola, el anillo de Bishop, la corona y la gloria.  1, record 4, Spanish, - fen%C3%B3meno%20de%20difracci%C3%B3n

Record 5,  Textual support,  English

Record number: 5, Textual support number: 1 DEF

Colored circle or circles around lights (...) seen by patients with glaucoma or with punctate lens opacities.  1, record 5, English, - halo%20symptom

Record 5,  Textual support,  French

Record number: 5, Textual support number: 1 DEF

(...) cercles brillants, souvent colorés (violet), que le sujet perçoit en regardant une source lumineuse.  1, record 5, French, - halos%20color%C3%A9s

Record number: 5, Textual support number: 1 CONT

Les halos colorés peuvent être la première manifestation d'un glaucome aigu.  1, record 5, French, - halos%20color%C3%A9s

Record 5,  Textual support,  Spanish