Author Topic: Fall Equinox, 22 Sept 2016  (Read 1120 times)

Felix

  • Gale
  • ****
  • Posts: 406
  • Station Details: Davis Wireless Vantage Pro-2 Plus with FARS, Leaf & Soil Moisture/Temp Sta + WeatherLink IP. Two prototype Sharx 3905 HD wide-angle webcams and one production model 3905, all using EvoCam v5.0. WeatherCat 3.03, macOS 10.14.2 Build 18C54 (Mojave).
Fall Equinox, 22 Sept 2016
« on: September 21, 2016, 11:35:59 AM »
The Autumnal Equinox (Latin: Equal Night) occurs Thursday, 10:21:07 a.m. at my station's latitude when the sun moves into the southern hemisphere for the next six months.


But I won't actually have equal portions of daytime and nighttime until Sunday, the 25th.


Bonus points for you X-Air if you can explain that without putting us to sleep.   [computer]

xairbusdriver

  • Storm
  • *****
  • Posts: 2199
    • EW7115 (E7115)
    • KTNGERMA20
    • Mid-South Weather
  • Station Details: Davis VP2 wireless + remote Anemometer/2014 Mac min - 10.13.4/WC 3.0
Re: Fall Equinox, 22 Sept 2016
« Reply #1 on: September 21, 2016, 06:47:33 PM »
According to <Wikipedia> ('cause I didn't really know the answer [blush], the problem is that the definition uses the center of the Sun. Since the Sun is actually a rather large disk, part of it becomes visible and starts lighting a spot on the Earth before the center can be seen. Likewise, while it is 'setting' its disk is still visible even after the center reaches the horizon. Therefore, the Sun's light makes the 'day' longer than the 'night'.

Then, there is the refraction of the Sun's light caused by the Earth's atmosphere. This extends the light even longer by a few seconds.

Thanks for asking, I never thought much about these facts. Even when flying into the rising Sun at O-Dark-Thirty (Hardly ever a pleasant experience!).

This whole problem could be fixed by moving the Earth a few hundred lightyears away from the Sun. Where's that <Congressman> who was concerned about Guam capsizing when you need him? [goofy]

Felix

  • Gale
  • ****
  • Posts: 406
  • Station Details: Davis Wireless Vantage Pro-2 Plus with FARS, Leaf & Soil Moisture/Temp Sta + WeatherLink IP. Two prototype Sharx 3905 HD wide-angle webcams and one production model 3905, all using EvoCam v5.0. WeatherCat 3.03, macOS 10.14.2 Build 18C54 (Mojave).
Re: Fall Equinox, 22 Sept 2016
« Reply #2 on: September 21, 2016, 08:04:47 PM »
Even when flying into the rising Sun at O-Dark-Thirty (Hardly ever a pleasant experience!).


Absolutely correct! When I was a young fighter pup, I was convinced the squadron schedulers had it in for me. Firstly, it seemed I was always in the first flight launch (O-Dark-Thirty in the morning) and secondly, the first tanker rendezvous was invariably on a track right into the rising sun. How could that happen every time unless by design?


Years later, when I was a Squadron/CC, it seemingly happened then too. At least I was lead by then but didn't want to tell the schedulers to knock that off and appear to be getting preferential treatment.


But by the time I was a Wing/DO, I said screw it, I'm not going to routinely do this anymore. My exec put out the word to the Squadron/CCs to schedule me for 'decent' takeoff times when flying proficiency trainers.

wurzelmac

  • Storm
  • *****
  • Posts: 1173
    • ITIROLPR2
    • Wetterstation Prägraten am Großvenediger
  • Station Details: Davis Vantage PRO2 Plus (24h fan aspirated, wireless) with UV/Solar | Weather Envoy Data Logger | Mac mini Mid 2011 2,7 GHz Intel Core i7 with 12 GB of RAM | 2x Canon EOS 1100D | macOS 10.13.6 HighSierra
Re: Fall Equinox, 22 Sept 2016
« Reply #3 on: October 29, 2016, 06:20:39 PM »
Just want to add some pictures to autumn 2016. Enjoy (or not).   ;)







Taken today. Family hiking.  ;D

Reinhard


xairbusdriver

  • Storm
  • *****
  • Posts: 2199
    • EW7115 (E7115)
    • KTNGERMA20
    • Mid-South Weather
  • Station Details: Davis VP2 wireless + remote Anemometer/2014 Mac min - 10.13.4/WC 3.0
Re: Fall Equinox, 22 Sept 2016
« Reply #4 on: October 29, 2016, 07:26:41 PM »
Always amazing to see how tenacious life can be! Continental plates build up, gravity, water and plants convert and wear down! "Who is man..."?

elagache

  • Global Moderator
  • Storm
  • *****
  • Posts: 5002
    • DW3835
    • KCAORIND10
    • Canebas Weather
  • Station Details: Davis Vantage Pro-2, MacBook Pro (Early 2011), macOS 10.13.6, WeatherCat 3
Thanks for sharing! (Re: Fall Equinox, 22 Sept 2016)
« Reply #5 on: October 29, 2016, 11:14:35 PM »
Dear Reinhard, X-Air, and WeatherCat adventurers,

Just want to add some pictures to autumn 2016. Enjoy (or not).   ;)

Thanks for sharing - indeed beautiful!  I sure wish I had time to explore country like that once more . . . .

Cheers, Edouard