Why does the sun rise in the northeast?

[JohnGalt]

Another way to think of this is to picture a globe in the sunshine (with the 23-degree tilt) and the shadow between day and night. On the days of the spring or fall equinox, neither pole is pointing towards the sun, and the shadow line (the terminator) passes both through the north and south poles at the same time. This causes the terminator to run north and south, and since the sun rises and sets perpendicular to that line, it rises/sets rises or sets directly to the east or west for everyone on the planet (poles excluded). This also means there are 12 hours between sunrise and sunset (equinox - equal nights), and sunrise is at 6:00 AM and sets at 6:00 PM (local standard time) for everyone.

As we move from spring to summer, the earth tilts more and more to the north (for the northern hemisphere). In the summer, the sun will still be directly to the east at 6:00 AM and west at 6:00 PM, but above the horizon, and the sun rises earlier because of the tilt. The tilt makes the sun rise to the northeast when the sun rises before 6:00 AM.

After the first day of fall, because the sun rises after 6:00 AM it will no longer be visible to the east (it’s below the horizon at that time); it rises to the south of east. On the first day of winter, the tilt is at its maximum away from the sun. If you try, you can “feel” the tilt between the different seasons.

[Learjeff]

@jtur88

Imagine that you are at the North Pole. The summer sun never sets at all. It just circles around you, close to the horizon. Now start walking south (really fast). The further south you go, the closer the sun dips toward the north horizon. When you reach the Arctic Circle, the midnight dip of the sun will touch the horizon, due north of where you are. Keep going south, and the sun will dip lower and lower below the horizon, still always to the north. As long as the number of hours of daylight are longer than the number of hours of darkness, those sunrises and sunsets will remain to the north of your east-west line, because the sun is still just circling around you, like it did at the North Pole, but you have sunsets and sunrises because it dips down below the North Pole.

Thanks. That explanation made it perfectly clear to me.

@USCDiver

It never occurred to me that the perpetual southern sun at noon would actually cross to NE/NW at sunrise and sunset!

Me neither! Ignorance fought.

When reading the discussion about the moon, I mused that I had a better-than-average intuitive understanding of the heavens and how they appear from Earth, and why, but also that I knew I didn’t have it all quite right, and that there were many with a far better grasp. This thread gave an example, while also improving my mental model.

I remember reading Michener’s Alaska, envisioning the scene where Arctic Native Americans (Athabascans? Inuit?) were having their annual celebration for the first sunrise of the year. My mental image abruptly collapsed when the text said “they saw the sun rise in the EAST …” Here I had them all facing south, and the time at noon. What was I thinking? [I still sometimes wonder whether Michener got it wrong, or some foolish editor “corrected” the text.]

[CC]

If you don’t live someplace where you can observe this phenomenon directly, then it’s harder to buy. But for anyone who has a view of sunrise or sunset, the facts speak for themselves. No replacing direct observation as a great way to learn about stuff.

[Nars_Glinley]

@jtur88

Imagine that you are at the North Pole. The summer sun never sets at all. It just circles around you, close to the horizon. Now start walking south (really fast). The further south you go, the closer the sun dips toward the north horizon. When you reach the Arctic Circle, the midnight dip of the sun will touch the horizon, due north of where you are. Keep going south, and the sun will dip lower and lower below the horizon, still always to the north. As long as the number of hours of daylight are longer than the number of hours of darkness, those sunrises and sunsets will remain to the north of your east-west line, because the sun is still just circling around you, like it did at the North Pole, but you have sunsets and sunrises because it dips down below the North Pole.

This was a very helpful illustration. It seems counterintuitive to me that the farther north you go, the farther north that the sun will rise. So in the UK in the summer, the sun starts well northeast at sunrise and then makes a much bigger arc across the sky (compared to the US anyway) to get to the Tropic of Cancer and then races back north for sunset. Interesting.

Thanks for all of the replies.

[hibernicus]

Where I live, the sun rises almost exactly north-east in midsummer and almost exactly south-east in midwinter.

Is there any simple, intuitive way to understand the direction where the sun appears at sunrise? For example, something like:
“The initial bearing on a great circle to the location on the earth where the sun is overhead”?

If it’s not that simple, I won’t be a bit surprised.

[USCDiver]

@CC

If you don’t live someplace where you can observe this phenomenon directly, then it’s harder to buy. But for anyone who has a view of sunrise or sunset, the facts speak for themselves. No replacing direct observation as a great way to learn about stuff.

The crazy thing is I lived way up in a high-rise dorm facing west for my entire Freshman year in college and even noted that the location of sunset changed as I had been taught. But I never knew exactly which direction was due west and so I never challenged my own misunderstanding of the phenomenon!