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Positions, we can exactly pin point the sun’s location at 9 a.m. As the sun’s path moves up and down through the seasons, the sun’s position at 9 a.m. Understanding the sun’s motion relative to a site is an important aspect of a good permaculture design, as various elements like plants, animals and solar devices depend on sun for their functionality.
Charting The Sun’s Motion In Relation To Your Home And Permaculture Site
SunCalc is a little app that shows sun movement and sunlight phases during the given day at the given location. Based on realistic 3D data and the time-dependent position of the Sun in the sky. As the earth continues its orbit around the sun, it reaches a point where its tilt is sideways to the sun. This is called as the Autumnal Equinox, where both the day and the night are of equal length with 12 hours each.
Permaculture and traditional buildings : the case for ecological restoration
Now, the sun’s path is lower in the sky, causing the northern hemisphere to receive less light and heat. The shortest day in this period is called the Winter Solstice. The summers are hotter because, the sun’s path is higher in the sky. This makes the days longer and it makes the summer sun more intense. To understand it more clearly, let’s do a simple demonstration using a flash light.
The four seasons
The first measurement is the sun’s direction on a compass. A straight line drawn from the sun to the horizon intersects a specific degree on a compass. This angle is a measure of the sun’s azimuth or elevation. The second measurement is the sun’s altitude or vertical angle. The combination of azimuth and altitude describes a specific spot on the sky dome. Now we can see where the sun would be shaded during the year.
Using these two measurements of solar azimuth and solar elevation, a chart can be drawn which will show how the sun’s position changes throughout the year. This chart is called the sun path chart and it shows how the sun’s path looks like from the earth’s surface. During summer, the North Pole is tilted towards the sun. As a consequence, the sun’s path is higher in the sky, causing the northern hemisphere to receive more light and heat.
Understanding Direction Based on the Sun - Geography Realm
Understanding Direction Based on the Sun.
Posted: Tue, 12 Jul 2022 07:00:00 GMT [source]
In a darkened room, switch on the flash light on a surface, at a direct 90° degree angle. Now, slowly reduce the angle to make it less direct. You will now observe that the size of the lit area has increased, but the intensity or brightness of it has reduced. What it implies is that, direct 90° degree angle provides more intense light than the inclined one. Higher it is in the sky, the more direct and intense the sunlight would be. Accurate timezones, sunrise and sunset for any location worldwide.
It shows what we would see, if we look towards the South Pole from this location. The y-axis represents the altitude or solar elevation, measured from 0° degrees on the horizon to 90° degrees directly overhead. The x-axis represents the sun’s direction on the compass, the solar azimuth.
Charting the sun’s location at any time in a day
But to actually chart the boundaries of a solar window for a real geographic location, one needs to know, how to measure the sun’s position in the sky. To pin-point the sun’s position on the sky dome, we need to make two measurements. Continuing further in its orbital path around the sun, the earth reaches the other side of the sun, with the northern hemisphere tilted farthest away from the sun.
The intersection of the sun’s altitude and azimuth on the graph shows the sun’s position in the sky. With the help of these two arc lines, we can chart the sun’s position at any time in a day, during the year, at a given location on the earth’s surface. On December 21st, 9.00 a.m., the sun has risen in the east and is low in the southern sky. On June 21st, at the same time of the day, it is higher in the sky. If we draw a line on the sky dome between these two 9 a.m.
As an example of how to make use of this chart, notice the lowest sun path, the path for Dec 21st. On this day, the sun would be shaded by a tree which stands between 135° and 150° degrees on the compass. You can see sun positions at sunrise, specified time and sunset.
This solar window is very important because, it is between 9.00 a.m. To harness the maximum possible energy at a given geographic location, the solar window should be clear and not be shaded by trees or any other obstacle between 9.00 a.m. It is for this reason that, before installing any solar device, one should analyze the installation site’s solar window and make sure that, there aren’t any shading obstacles.
The thin orange curve is the current sun trajectory, and the yellow area around is the variation of sun trajectories during the year. The closer a point is to the center, the higher is the sun above the horizon. The colors on the time slider above show sunlight coverage during the day.
Other elements of a permaculture design like solar panels are also needed to be placed thoughtfully to obtain maximum exposure to the sun to harvest as much energy as possible. Even animals can derive benefits from thoughtful solar designs, as they too like to have winter warmth and summer shade. Beehives, chickens, fish ponds and livestock, all appreciate sunshine in winter and shade in summer. The chart can be overlaid with the locations of shading obstacles like trees or buildings. Further, one can overlay the sun’s paths of the shortest and longest day of the year. On top of that, the position lines of the hours of the day can also be graphed.
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