What is a word for the length of sky between directly overhead and horizon?

What is a word that is closely defined to "the vertical length of sky between directly overhead and the horizon"?

Example for definition: "The sun shown through the fog in the |between-zenith-horizon|"

It may also be defined as "the range of directions between directly overhead and the horizon."

Example for definition: "The sun shown through the fog in the |between-overhead-horizon| sky"

I would prefer one word.

• Something of a guess - might it be the "vertical azimuth"? Oct 3, 2013 at 14:09
• Could you give an example sentence where you would like to use the word? Given that it's actually a virtual thing (a quarter of a great circle on the celestial sphere, from zenith to horizon) there may not be a word at all. An example sentence would help if it's necessary to come up with a non-technical word or expression. Oct 3, 2013 at 14:14
• @AndrewLeach I edited my question to include examples. Oct 3, 2013 at 14:20
• The sun shone though the fog at an acute angle Oct 3, 2013 at 14:22
• There's not a name for it, you should use "the sun shone through the fog above the horizon" or "the sun shone through the surrounding fog" Oct 3, 2013 at 14:35

You could call that range of angles the first quadrant, using quadrant in one or more of the following senses. I don't know of a more-specific term for altitudes between horizon and zenith.

1. One of the four sections made by dividing an area with two perpendicular lines.
2. (mathematics) The four regions of the Cartesian plane bounded by the x-axis and y-axis.
3. (geometry) One fourth of a circle or disc; a sector with an angle of 90°.

In sense 2, the region where both x and y are positive is quadrant 1; quadrant 2 is counterclockwise from 1; etc.

In the context “The sun shown through the fog in the |between-overhead-horizon| sky”, one might say “The sun shown through the fog in the quadrant of sky before us”.

• The seemingly insignificant "in the" in the sentence thoroughly depicts the fact that the sun shining through the fog is contained within my desired direction: (quadrant of sky before us). Oct 3, 2013 at 14:43

Measuring the length of the arc wouldn't make any sense, as its length would vary depending on the distance of the arc from the observer.

You can speak of the angle of the arc as its altitude or elevation in astronomical terms, usually measured in degrees. So from the horizon to the zenith, your altitude is 90 degrees. The arc itself is a part of a meridian.

In mathematics the term appears to be polar angle, represented by φ.

• Could I say "The sun shown through the fog in the mid-meridian sky?" Or would it translate to that the sun was hidden beneath the horizon? Oct 3, 2013 at 14:24
• @Prague No, I don't think that would be widely understood, even among astronomers. I answered before you had added context to your answer. I'm not familiar with any vernacular term. We speak of a high sun or a sun that is low in the sky, but rarely get more specific; rather than the sun's vertical position, it is the time of day that is usually referenced: The mid-morning sun burned through the fog. Oct 3, 2013 at 14:32

An angle with any degree less than 90 is an acute angle

The sun shone though the fog at an acute angle

What you describe would be a 'chord' (geometry) if we assume a defined altitude to your 'overhead' reference.

A chord of a circle is a geometric line segment whose endpoints both lie on the circle.