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Sun path, sometimes also called day arc, refers to the daily (sunrise to sunset) and seasonal arc-like path that the Sun appears to follow across the sky as the Earth rotates and orbits the Sun. The Sun's path affects the length of daytime experienced and amount of daylight received along a certain latitude during a given season.
Given the different Sun incidence in different positions in the orbit, it is necessary to define a standard point of the orbit of the planet, to define the planet position in the orbit at each moment of the year w.r.t such point; this point is called with several names: vernal equinox, spring equinox, March equinox, all equivalent, and named considering northern hemisphere seasons.
The mean calendar year of such a calendar approximates the sidereal year. Leaping from one lunation to another, but one Sidereal year is the period between two occurrences of the sun, as measured by the stars' solar calendar, which is derived from the Earth's orbit around the sun every 28 years. [3]
For example, with an axial tilt is 23°, and at a latitude of 45°, then the summer's peak sun angle is 68° (giving sin(68°) = 93% insolation at the surface), while winter's least sun angle is 22° (giving sin(22°) = 37% insolation at the surface). Thus, the greater the axial tilt, the stronger the seasons' variations at a given latitude. [4]
The sun enters and leaves each zodiacal constellation slightly later each year at the rate of about 1 day every 72 years. For more information, see precession of the equinoxes . On the Tropical Circles, the Sun is directly overhead only once per year, on the corresponding solstice.
A season is a division of the year [1] based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's tilted orbit around the Sun.
Articles relating to seasons, divisions of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth , seasons are the result of Earth's orbit around the Sun and Earth's axial tilt relative to the ecliptic plane.
A study of temperature records over the past 300 years [1] suggests that the seasonal year is governed by the anomalistic year rather than the tropical year. This suggestion is surprising because the seasons have been thought to be governed by the tilt of the Earth's axis (see Effect of sun angle on climate). The two types of years differ by a ...