by canopia » Mon Sep 23, 2019 4:28 pm
Thank you Mark. I had photographed this image from the rooftop of our apartment building in Bursa, Turkey; located at 40° 11' N, 29° 4' E. -There are already inevitable messages about the duration between sunrise and sunset being longer than 12 hours on equinox days. This is further complicated by horizon profiles; like at my location.
For the December solstice, the Sun should normally rise at 07:23 local time (GMT+2) and after a short 9 hours 18 minutes of day, it would set at 16:41. But due south and southeast of Bursa lies Uludağ, a mountain rising 2.5 km and blocking a considerable sky. So, when I took the first picture when the Sun appeared from behind Uludag, it was 08:11. The sunset was also earlier because of hills due southwest, at 16:03. So, the shortest day of the year was even shorter for Bursa; 7 hours 52 minutes at my location.
On the March equinox day, the sun would rise at 06:07 (GMT+2) and set at 18:16. Because of the clouds, I could take the first picture 3 minutes after the actual sunrise (at 06:14) which was somewhat dimmed by haze; at 06:17. Sunset was less eventful and much easier, at 18:09. That was the equinox, with an actual daylight of 11 hours 55 minutes instead of a not-so-equal day of 12 hours and 9 minutes, those 9 minutes resulting from atmospheric effects and Sun's angular size.
On the June solstice day, sunrise and sunset were predicted to occur at 05:34 and 20:36 daylight time (GMT+3), resulting a longest day of 15 hours and 2 minutes. But the actual sunrise was at 05:53, when the Sun appeared from behind Avdan Dağı, a smaller mountain due northeast rising about 1000 meters. Actual sunset was just a couple minutes earlier, at 20:34; making our longest day 14 hours 41 minutes long.
Tunç Tezel
http://www.twanight.org
MarkBour wrote: ↑Mon Sep 23, 2019 3:32 pm
I love images like today's APOD! It looks like summer solstice at that location was about 15 hours of daylight, the equinox 12, and the winter solstice about 8 hours of daylight. The location of the camera is a great location for solar panels ... no significant blockage!
Chris Peterson wrote: ↑Mon Sep 23, 2019 4:16 am
Oh, oh... how long until the regular (and rather lame) complaint that day and night aren't equal on the equinox? Counting down...
Ok, refraction / the edge of the disk versus center of disk / exact moment of equinox, yada yada yada ?
Happy to oblige.
Thank you Mark. I had photographed this image from the rooftop of our apartment building in Bursa, Turkey; located at 40° 11' N, 29° 4' E. -There are already inevitable messages about the duration between sunrise and sunset being longer than 12 hours on equinox days. This is further complicated by horizon profiles; like at my location.
For the December solstice, the Sun should normally rise at 07:23 local time (GMT+2) and after a short 9 hours 18 minutes of day, it would set at 16:41. But due south and southeast of Bursa lies Uludağ, a mountain rising 2.5 km and blocking a considerable sky. So, when I took the first picture when the Sun appeared from behind Uludag, it was 08:11. The sunset was also earlier because of hills due southwest, at 16:03. So, the shortest day of the year was even shorter for Bursa; 7 hours 52 minutes at my location.
On the March equinox day, the sun would rise at 06:07 (GMT+2) and set at 18:16. Because of the clouds, I could take the first picture 3 minutes after the actual sunrise (at 06:14) which was somewhat dimmed by haze; at 06:17. Sunset was less eventful and much easier, at 18:09. That was the equinox, with an actual daylight of 11 hours 55 minutes instead of a not-so-equal day of 12 hours and 9 minutes, those 9 minutes resulting from atmospheric effects and Sun's angular size.
On the June solstice day, sunrise and sunset were predicted to occur at 05:34 and 20:36 daylight time (GMT+3), resulting a longest day of 15 hours and 2 minutes. But the actual sunrise was at 05:53, when the Sun appeared from behind Avdan Dağı, a smaller mountain due northeast rising about 1000 meters. Actual sunset was just a couple minutes earlier, at 20:34; making our longest day 14 hours 41 minutes long.
Tunç Tezel
[url]http://www.twanight.org[/url]
[quote=MarkBour post_id=295490 time=1569252759 user_id=141361]
I love images like today's APOD! It looks like summer solstice at that location was about 15 hours of daylight, the equinox 12, and the winter solstice about 8 hours of daylight. The location of the camera is a great location for solar panels ... no significant blockage!
[quote="Chris Peterson" post_id=295477 time=1569212219 user_id=117706]
Oh, oh... how long until the regular (and rather lame) complaint that day and night aren't equal on the equinox? Counting down...
[/quote]
Ok, refraction / the edge of the disk versus center of disk / exact moment of equinox, yada yada yada ?
Happy to oblige.
[/quote]