Sun Degrees Above Horizon

The Sun's Altitude: Understanding Degrees Above the Horizon

The sun's position in the sky, specifically its angular height above the horizon, plays a crucial role in numerous aspects of our lives, from the amount of solar energy received to the length of daylight hours and even the accuracy of navigation. This article aims to demystify the concept of "sun degrees above the horizon" (also known as solar altitude), explaining its calculation, significance, and practical applications.

1. Defining Solar Altitude

Solar altitude, measured in degrees, represents the vertical angle between the sun's center and the horizon. Zero degrees signifies the sun on the horizon (sunrise or sunset), while 90 degrees indicates the sun directly overhead (solar noon at the equator on the equinoxes). Values between 0 and 90 degrees reflect the sun's position at any other time during the day. The higher the solar altitude, the more intense the solar radiation reaching the earth's surface.

2. Factors Influencing Solar Altitude

Several factors determine the sun's altitude at a given location and time:

Latitude: Locations closer to the equator generally experience higher solar altitudes than those at higher latitudes. This is because the sun's rays strike the Earth more directly near the equator. For instance, a location at 0° latitude (on the equator) will have a maximum solar altitude of 90° at solar noon during the equinoxes.

Time of Day: Solar altitude changes throughout the day, reaching its maximum at solar noon (not necessarily 12:00 PM local time) and decreasing towards sunrise and sunset. The exact time of solar noon varies depending on the time of year and longitude.

Time of Year: The Earth's axial tilt (23.5°) causes variations in solar altitude throughout the year. During summer solstice, the sun's altitude is higher in the northern hemisphere, resulting in longer days and increased solar radiation. Conversely, during winter solstice, the altitude is lower, leading to shorter days and less intense solar radiation.

Longitude: Longitude affects the timing of solar noon but has a minimal direct impact on the maximum solar altitude on a given day.

3. Calculating Solar Altitude

While precise calculation involves complex astronomical formulas considering the Earth's elliptical orbit and atmospheric refraction, a simplified approximation can be obtained using the following formula:

sin(altitude) = sin(latitude) sin(declination) + cos(latitude) cos(declination) cos(hour angle)

Where:

altitude: The sun's altitude in degrees.
latitude: The observer's latitude in degrees.
declination: The sun's declination (its angular distance north or south of the celestial equator) which varies throughout the year. This value can be obtained from astronomical tables or online calculators.
hour angle: The angular distance of the sun east or west of the local meridian (the line passing through the north and south celestial poles and the observer's zenith). It's approximately 15 degrees per hour from solar noon.

4. Applications of Solar Altitude

Understanding solar altitude has various practical applications:

Solar Energy: The angle of the sun directly impacts the efficiency of solar panels. Optimizing panel orientation to maximize solar altitude throughout the day increases energy generation.

Architecture and Design: Building design considers solar altitude to minimize heat gain in summer and maximize it in winter, improving energy efficiency and occupant comfort.

Agriculture: Farmers utilize knowledge of solar altitude to optimize crop planting and irrigation schedules, ensuring optimal sunlight exposure for better yields.

Navigation: Historically, sailors used the sun's altitude to determine their latitude. Modern navigation systems still utilize solar data, although indirectly.

Photography: Photographers consider solar altitude to determine the best time for taking pictures, considering factors like shadow length and light quality.

Example: Let's consider a location at 40°N latitude on the summer solstice (declination ≈ 23.5°). At solar noon (hour angle = 0°), the approximate solar altitude would be:

sin(altitude) = sin(40°) sin(23.5°) + cos(40°) cos(23.5°) cos(0°) ≈ 0.91

Altitude ≈ arcsin(0.91) ≈ 65.5°

This indicates a high solar altitude, resulting in intense sunlight.

5. Conclusion

Solar altitude is a fundamental concept with far-reaching implications across various disciplines. Understanding how latitude, time, and the Earth's axial tilt influence this crucial factor allows for better planning and optimization in areas ranging from renewable energy to architecture and agriculture. Accurate prediction and utilization of solar altitude contribute to increased efficiency and sustainability.

FAQs

1. Q: How does atmospheric refraction affect solar altitude? A: Atmospheric refraction bends sunlight as it passes through the atmosphere, making the sun appear slightly higher than its actual geometric position, particularly near the horizon.

2. Q: Can I easily calculate solar altitude using a smartphone app? A: Yes, many weather and astronomy apps provide real-time solar altitude information based on your location and time.

3. Q: What is the difference between solar altitude and solar azimuth? A: Solar altitude is the vertical angle, while solar azimuth is the horizontal angle (direction) of the sun relative to north.

4. Q: How does cloud cover affect solar altitude's practical impact? A: Cloud cover significantly reduces the amount of solar radiation reaching the Earth's surface, regardless of solar altitude.

5. Q: Is solar noon always at 12:00 PM local time? A: No, solar noon varies slightly depending on the time of year and the observer's longitude due to the Earth's axial tilt and its orbit.

Search Results:

How To Calculate The Sun's Altitude - Sciencing 8 Dec 2020 · 71.14 degrees above the horizon. This is about 80 percent of the way from the horizon to the zenith. Six months later, on December 22 or 23, the autumnal equinox has …

SunCalc - sunrise, sunset, shadow length, solar eclipse, sun … The thin yellow-colored curve shows the trajectory of the sun, the yellow deposit shows the variation of the path of the sun throughout the year. The closer a point in the center, the higher …

Sun path - Wikipedia At the time of the summer or winter solstices, the Sun is 23.44° degrees above or below the horizon, respectively, irrespective of time of day. Whilst the Sun is up (during summer months) …

Sun position at a given date. Azimuth and elevation table. Calculation of azimuth and elevation of the sun above the horizon for a given position and time. Table with one hour increments.

Calculate Sun Position - Rechneronline When the height above horizon is negative, the Sun is below the horizon, it is night. The direction is shown in degrees and as an abbreviation, with N for North, S for South, E for East and W for …

Sun Positions - axel tanner - axltnnr.io 14 May 2022 · Tracing the elevation of the sun above the horizon (vertical -90 to 90 degrees above the horizon) throughout the year 2022 (horizontal January to December) - the horizontal …

NOAA Solar Position Calculator - National Oceanic and … Results are given in the following units: Equation of Time in minutes of time; Solar Declination in degrees, with positive to the north; Azimuth in degrees clockwise from north; Elevation in …

Sun Angle Calculator The elevation (α \boldsymbol{\alpha} α) measures the Sun's height relative to the horizon line. It ranges from -90° to 90°. The positive values denote the Sun is above the horizon, while …

Sun Position Calculator - A.Tools It quantifies how high the Sun appears in the sky from an observer's point of view. When the Sun is on the horizon, the elevation angle is 0 degrees; when it is directly overhead (at the zenith), …

Declination and maximum altitude of the Sun above the horizon … This online calculator calculates the declination of the Sun on a given date and the maximum altitude above the horizon on that day for a given latitude.

Climate and Average Weather Year Round in Tabriz Iran Solar elevation and azimuth over the course of the year 2025. The black lines are lines of constant solar elevation (the angle of the sun above the horizon, in degrees). The background …

Solar energy potential according to climatic and geometrical … 1 Jun 2019 · Measuring altitude and azimuth is essential in analyzing the sun's path. The angular distance above the horizon is altitude that measured to the horizon perpendicularly. The …

Sun Altitude Calculator - Calculator Doc 2 Feb 2025 · The sun altitude calculator is a useful tool for determining how high the sun appears in the sky based on location and solar declination. Whether for astronomy, solar energy, or …

The Sun's altitude above the horizon in Tabriz (East Azerbaijan ... 24 Jan 2025 · The angular altitude of the Sun above the horizon in Tabriz (East Azerbaijan Province, Iran). The direction of sunrise and sunset, the altitude of the Sun at solar noon …

Azimuth and solar elevation angle - Online calculators The negative altitude above the horizon corresponds to the dark time of the day - the Sun is "under" the horizon. The intersection with the horizon in the morning occurs at the 90 degrees …

Calculation of sun’s position in the sky for each location on the … Polar coordinates are based on a circle where the solar elevation is read on the various concentric circles, from 0° to 90° degrees, the azimuth is the angle going around the circle from 0° to …

Sun position at a given date. Azimuth and elevation table. Calculation of azimuth and elevation of the sun above the horizon for a given position and time. Table with one hour increments.

Tabrīz : Sun direction, dawn sunrise sunset dusk and more Dawn — A time that marks the beginning of the twilight before sunrise. It is recognized by the presence of weak sunlight, while the sun itself is still below the horizon. Sunrise — The …

Declination and maximum altitude of the Sun above the horizon … This online calculator calculates the declination of the Sun on a given date and the maximum altitude above the horizon on that day for a given latitude

Sun Degrees Above Horizon

The Sun's Altitude: Understanding Degrees Above the Horizon

1. Defining Solar Altitude

2. Factors Influencing Solar Altitude

3. Calculating Solar Altitude

4. Applications of Solar Altitude

5. Conclusion

FAQs

Links:

Converter Tool

Conversion Result:

Formatted Text:

Search Results: