http://citycyclingedinburgh.info/bbpress/ CityCyclingEdinburgh Forum » Topic: Sunrises and sunsets en Sun, 31 May 2026 14:04:44 +0000 http://citycyclingedinburgh.info/bbpress/topic.php?id=19224#post-294177 Thu, 25 Oct 2018 16:10:49 +0000 acsimpson 294177@http://citycyclingedinburgh.info/bbpress/ <p>Heavy pollution can create some very red sunsets. The best I saw was in Santiago from a hill just above the smog level. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19224#post-294161 Thu, 25 Oct 2018 14:32:51 +0000 bill 294161@http://citycyclingedinburgh.info/bbpress/ <p>Really enjoyed reading this thread (almost as much as the snail one) :D </p> <p>Not as pretty as the BBC ones but here are my photos of the sunrise/sunset from the last couple of days.</p> <p><a href="https://flic.kr/p/QgkPwj"><img src="https://farm2.staticflickr.com/1918/31678739298_6a0f9ff4da_n.jpg"></a><a href="https://flic.kr/p/QgkPwj">IMG_20181019_074832941</a> by <a href="https://www.flickr.com/photos/147968794@N07/">Bill Harriman</a>, on Flickr</p> <p><a href="https://flic.kr/p/2cpcDwn"><img src="https://farm2.staticflickr.com/1933/45551168861_80df334102_n.jpg"></a><a href="https://flic.kr/p/2cpcDwn">IMG_20181024_180139222_2</a> by <a href="https://www.flickr.com/photos/147968794@N07/">Bill Harriman</a>, on Flickr </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19224#post-294155 Thu, 25 Oct 2018 13:50:48 +0000 paddyirish 294155@http://citycyclingedinburgh.info/bbpress/ <p>Excellent - knew I'd get a mix of informative and "tangential" responses. Great work!</p> <p><a href="https://www.bbc.co.uk/news/uk-45973366">The BBC has picked up on the last few days worth</a> </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19224#post-294153 Thu, 25 Oct 2018 13:24:30 +0000 dougal 294153@http://citycyclingedinburgh.info/bbpress/ <p>So, the smoke from disposing of all those burgundy passports. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19224#post-294152 Thu, 25 Oct 2018 12:44:44 +0000 I were right about that saddle 294152@http://citycyclingedinburgh.info/bbpress/ <p><em>The smoke from bonfires of corpses of cows killed after BSE outbreaks would have had noticeable local effects on sunsets</em></p> <p>CCE gold. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19224#post-294147 Thu, 25 Oct 2018 12:17:56 +0000 wingpig 294147@http://citycyclingedinburgh.info/bbpress/ <p>The smoke from bonfires of corpses of cows killed after BSE outbreaks would have had noticeable local effects on sunsets, so the badger cull might be very slightly responsible if they're burning them with lots of moist green wood and leaves. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19224#post-294145 Thu, 25 Oct 2018 12:05:35 +0000 steveo 294145@http://citycyclingedinburgh.info/bbpress/ <p>Interesting cloud formations make better sunsets. Interesting clouds are usually due to changeable weather, which we have in spades at this time of year.</p> <p>Or brexit if you prefer :) </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19224#post-294144 Thu, 25 Oct 2018 12:02:04 +0000 wingpig 294144@http://citycyclingedinburgh.info/bbpress/ <p>The length of time it takes for the sun to go from wholly visible to wholly occluded by the horizon varies with the distance from the equator combined with the seasonal variation caused by the earth's axial tilt. A sunrise/sunset calendar will show this variation throughout the year. In summary: if the sun is directly overhead at noon, sunrises and sunsets are over more quickly than they would be if the sun was not directly overhead at noon. In slightly more detail: the apparent angular velocity of the sun doesn't change much, so a sun with apparent motion perpendicular to the horizon will move from before it to beyond it more quickly than a sun with an oblique path, which has to cover greater overall apparent distance to achieve the same vertical component (its own apparent height).</p> <p>The momentary appearance of a sunset at any time is entirely down to atmospheric conditions - particles, thermoclines and whether or not there are any clouds to be illuminated by the affected light. These can vary seasonally. Changing weather patterns could result in relative local differences in atmospheric pressure, humidity, particles, temperature gradients etc. but these can only affect the appearance of a sunrise or sunset if they happen to end up in the right place to divert photons from the atmosphere into your eyes at any given time. </p> http://citycyclingedinburgh.info/bbpress/topic.php?id=19224#post-294134 Thu, 25 Oct 2018 11:00:27 +0000 paddyirish 294134@http://citycyclingedinburgh.info/bbpress/ <p>One for the scientists (amateur or professional) of CCE</p> <p>September/October has always been a good time for good sunrises and sunsets, especially as they occur around commute time, but this year's seem to be better than I remember.</p> <p>Is this down to chance, or something more sinister like pollution/global warming? Or Brexit?:-) </p>