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If a sunset is defined as the tip of the sun touching the horizon when would it be defined in the mountains? If the sunsets at 8:24 pm in Salt Lake city does that mean the tip touches the mountain or is still going down?
Rebecca H.
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Sunset times are definitely different depending on where you are. Clearly the time of sunset is different if one person is in Salt Lake or say, somewhere like Wendover (west of Salt Lake).
From the US Naval Observatory the sunrise and set is defined as "Sunrise and sunset conventionally refer to the times when the upper edge of the disk of the Sun is on the horizon, considered unobstructed relative to the location of interest. Atmospheric conditions are assumed to be average, and the location is in a level region on the Earth's surface."
Using this definition, it's the upper edge of the sun we're concerned with. Also in the definition it says that's it's 'relative' to location. So the view must be unobstructed. So if you can see the very top of the disk, then there's your sunset time.
Sunset times can be slightly different in towns that are close to eachother. For example:
May 16th sunset times
Salt Lake at 8:39 pm Park City at 8:37 pm Wendover at 8:48 pm Alta at 8:37 pm Richfield at 8:35 pm Tooele at 8:40 pm
The time you observe the sunset might be a little different depending on your view or obstruction. The times listed for Salt Lake should be relatively close to other places along the Wasatch Front, so hopefully it's not too far off from where you are trying to pinpoint.
Your question asks specifically if the sun is still going down, yes it is, we just can't see any more of it. The earth is rotating all the time, so our view of the sun is constantly changing. The sunset time is the last view of the top of sun's disk, it's still 'moving' relative to us though.
Answered by KSL Meteorologist Dina Freedman.
