Height of the Sun in UK.

[Guest]

I have been out with the hound walking this lunchtime. The skies are clear and the Sun is very bright. But at mid day in winter the Sun still appears low. It is deceptively darker than the mid day Sun at the height of Summer. Fantasy I know, but I often have the thought that if you were standing  in a clear sky during Summer and could transport the winter Sun to Summer then the sky would become very much darker instantly.

Below is a link showing the Suns height at  different stages of the year.

 

Sun path - Wikipedia https://en.m.wikipedia.org/wiki/Sun_path#:~:text=Solstice day arcs as viewed,93.44° altitude in summer.

[wulfrun]

Worth looking up the Wikipedia page on "Analemma" too, which shows the sun's position on the same time each day from a fixed location. It's a distorted figure-8.

Edited December 12, 2020 by wulfrun

[Louis D]

1 hour ago, Grumpy Martian said:

It is deceptively darker than the mid day Sun at the height of Summer.

I guess you've rarely trekked across a snow covered field in winter under a noon sun.  It is still blinding bright.  I had wear reflective sunglasses back in the 80s to make it bearable to walk between classes during my college days in the upper Midwest.

[Moonshed]

59 minutes ago, wulfrun said:

Worth looking up the Wikipedia page on "Analemma" too, which shows the sun's position on the same time each day from a fixed location. It's a distorted figure-8.

The analemma always fascinates me, it’s a beautiful way of showing the position of the sun over the course of a year.

Edited December 12, 2020 by Moonshed

[Guest]

2 minutes ago, Louis D said:

I guess you've rarely trekked across a snow covered field in winter under a noon sun.  It is still blinding bright.  I had wear reflective sunglasses back in the 80s to make it bearable to walk between classes during my college days in the upper Midwest.

I agree with you. The sun is bright Winter or Summer. But the actual sky appears darker during a clear day in Winter

[Stu]

Just now, Grumpy Martian said:

I agree with you. The sun is bright Winter or Summer. But the actual sky appears darker during a clear day in Winter

I guess the sunlight is travelling through a lot more atmosphere when down low in the winter which attenuates its brightness a little. That’s why it is so much easier to get sunburned in summer with the sun high in the sky and with much less atmosphere to travel through.

[John]

On the bonus side, the nature of the sunlight in winter here, as it falls across the landscape, can be rather lovely.

I've just come in from a rather nice, if muddy, rural hike having really enjoyed extensive views across to Wales and in the other direction the Mendip Hills and Somerset Levels

The most distant hill is Glastonbury Tor:

 

[Louis D]

46 minutes ago, Stu said:

That’s why it is so much easier to get sunburned in summer with the sun high in the sky and with much less atmosphere to travel through.

We learned the hard way that it is still easy to get sunburned in Texas in the winter.  My niece was visiting in early February one year.  We went for a hike in a state park in an area with little tree cover.  Because it was in the 80s, she just wore a sleeveless top to stay cool.  She got the worst sunburn on the tops of her exposed shoulders.  Lesson learned, we're pretty far south, so even in winter, the sun can still be intense.

[Tiny Clanger]

47 minutes ago, Louis D said:

I guess you've rarely trekked across a snow covered field in winter under a noon sun.  It is still blinding bright.  I had wear reflective sunglasses back in the 80s to make it bearable to walk between classes during my college days in the upper Midwest.

Snow blindness is a well known hazard for winter outdoors folk , especially those at high altitude where more UV gets through the atmosphere. Sort of sunburn of the cornea , unpleasant but I think temporary. Hence alpinist's expensive goggles .

As hazards go, in the UK right now with utter gloomy grey skies and globally  warmed temperatures, it's way down the list of probabilities, but many years ago a walk home on lying snow under a full moon was so memorably, coldly lit that even my somewhat wine addled brain was impressed .

[Ships and Stars]

I used Suncalc for desktop if I want to see accurate solar positions, the twin to the equally handy Mooncalc that I use for planning dark sky trips when the moon is far enough below the horizon for faint DSO chasing.

At my latitude, the sun only rises about 9.5 -9.8 deg above the horizon this time of year, with just under 7 hours of 'daylight', using the term very loosely, so if I actually want to see the sun, I have to climb a small hill south of our house around noon, or get in a boat and go about 2-3 miles offshore and look at the southern horizon. 

The sun won't directly shine on our house again until late January I think, and even then, it will only be for a few minutes.

In the summer on June 21st, the sun here only hits a maximum altitude around 56 degrees but never really drops far below the horizon.

Edited December 12, 2020 by Ships and Stars

[Tiny Clanger]

2 hours ago, Ships and Stars said:

I used Suncalc for desktop if I want to see accurate solar positions, the twin to the equally handy Mooncalc that I use for planning dark sky trips when the moon is far enough below the horizon for faint DSO chasing.

At my latitude, the sun only rises about 9.5 -9.8 deg above the horizon this time of year, with just under 7 hours of 'daylight', using the term very loosely, so if I actually want to see the sun, I have to climb a small hill south of our house around noon, or get in a boat and go about 2-3 miles offshore and look at the southern horizon. 

The sun won't directly shine on our house again until late January I think, and even then, it will only be for a few minutes.

In the summer on June 21st, the sun here only hits a maximum altitude around 56 degrees but never really drops far below the horizon.

It always seems to me a failure of modern life that (apart from Outdoorsy people, farmers and gardeners) so many of us are separated and insulated from the seasons.

That disconnect must account for some of the astonishment people show to things like Neolithic grave passages being aligned to the winter solstice... as if those stone age folk didn't have an intimate connection with , and understanding of, the apparent path of the Sun. Much easier to use an online tool than drag some big rocks around and stand them on end in the correct places though ! 😀

[JamesF]

To be fair it was probably much easier to connect with the paths of the Sun and Moon (and the phase of the latter) before we messed the climate up to the point that we now get six months of permacloud.

James

[niallk]

I particularly noticed this when i got a Lunt LS50DS - and the alt angle on my mount when observing - and how i have to observe from my front garden in winter.

My own effort at a solar graph

[JamesF]

4 hours ago, John said:

I've just come in from a rather nice, if muddy, rural hike having really enjoyed extensive views across to Wales and in the other direction the Mendip Hills and Somerset Levels

Is that the M5 down in the valley, John?  It all looks oddly familiar though I've never seen things from that viewpoint before.

James

[JamesF]

4 minutes ago, niallk said:

My own effort at a solar graph

I'd like to have a go at one myself soon, but given my current lack of gainful employment I'm also every tempted to have a crack at creating an annalemma image.

James

[Louis D]

4 hours ago, Ships and Stars said:

The sun won't directly shine on our house again until late January I think, and even then, it will only be for a few minutes.

Viganella, Italy and Rjukan, Norway both use mirrors on nearby ridges to reflect light into their town squares during the winter since they're also in perpetual shade at that time.  I wonder if you could work up a similar solution. 😉

Edited December 12, 2020 by Louis D

[Guest]

1 hour ago, Louis D said:

Viganella, Italy and Rjukan, Norway both use mirrors on nearby ridges to reflect light into their town squares during the winter since they're also in perpetual shade at that time.  I wonder if you could work up a similar solution. 😉

This is really interesting. I've never heard of this before. This highlights what a good astronomy forum this is.

[Moonshed]

2 hours ago, Louis D said:

Viganella, Italy and Rjukan, Norway both use mirrors on nearby ridges to reflect light into their town squares during the winter since they're also in perpetual shade at that time.  I wonder if you could work up a similar solution. 😉

You might need to invest in some sun glasses, you can have mine if you like as I have no need of them at the moment.

Edited December 12, 2020 by Moonshed

[LukeSkywatcher]

Try living in a bungalow during the winter. I have to have the lights on from the time I wake until I go to bed. The rear of my house faces south and still dark enough to need lights. The front faces north and is darkness during winter.

[LukeSkywatcher]

23 hours ago, Louis D said:

We learned the hard way that it is still easy to get sunburned in Texas in the winter.  My niece was visiting in early February one year.  We went for a hike in a state park in an area with little tree cover.  Because it was in the 80s, she just wore a sleeveless top to stay cool.  She got the worst sunburn on the tops of her exposed shoulders.  Lesson learned, we're pretty far south, so even in winter, the sun can still be intense.

What is 80's Fahrenheit in Celsius?. That about low 20s Celcsius? That's ok for Feb. It's nearly Sping. 

Edit......

80F=26C. Damn that's crazy for Feb. Here in the UK and Ireland, that's a heatwave during Summer.

Edited December 13, 2020 by LukeSkywatcher

[Louis D]

11 hours ago, LukeSkywatcher said:

80F=26C. Damn that's crazy for Feb. Here in the UK and Ireland, that's a heatwave during Summer.

We hit 91F on February 15, 2019.  That's 33C I guess.  Of course, it's a dry heat that time of the year.

It's nice having mostly warm winters, though, to make up for our excessively hot summers.  For instance, we had 90 days above 100F (38C) in 2011.  It was pretty miserable that year.  Y'all would probably melt if that happened in Ireland.

[Tiny Clanger]

4 minutes ago, Louis D said:

We hit 91F on February 15, 2019.  That's 33C I guess.  Of course, it's a dry heat that time of the year.

It's nice having mostly warm winters, though, to make up for our excessively hot summers.  For instance, we had 90 days above 100F (38C) in 2011.  It was pretty miserable that year.  Y'all would probably melt if that happened in Ireland.

I have friends who moved to the USA years ago , and I visited them when they lived in Scottsdale Az . I recall  seeing a t-shirt which pictured two vultures perched on a longhorn cow skull : one vulture was saying to the  other :

"Yeah, but it's a dry heat ..." 😀

[Louis D]

5 minutes ago, Tiny Clanger said:

I have friends who moved to the USA years ago , and I visited them when they lived in Scottsdale Az . I recall  seeing a t-shirt which pictured two vultures perched on a longhorn cow skull : one vulture was saying to the  other :

"Yeah, but it's a dry heat ..." 😀

I've been in 110F humid heat in St. Louis and 118F dry heat in Phoenix.  I'll take the dry heat any day.  If you drink lots of water, the dry heat is tolerable.  There's just no way to stay cool in humid heat that high.  I was starting to suffer heat exhaustion until I retreated to air conditioning that day.  That despite drinking 1.5 liters of water in 2 hours.

My favorite vulture cartoon is the following Far Side:

[Voyager 3]

I think I'm going to reign supreme here 😁 ... 41°C in mid may is common here at my location . I donk what's there but 38°-39° , mmm not much of a difference but 39°-40° is mind boggling 😂.

[Louis D]

3 hours ago, Voyager 3 said:

I think I'm going to reign supreme here 😁 ... 41°C in mid may is common here at my location . I donk what's there but 38°-39° , mmm not much of a difference but 39°-40° is mind boggling 😂.

110F=43C, which we hit many summers here in Texas, and 118F=48C, which is fairly common in Phoenix.  Imagine spending 90 days at or above 38C with high humidity.  Basically, mid-June through mid-September is spent entirely indoors in the A/C here.  Phoenix spent 144 days above 100F=43C this past summer, which was a new record for them.  Of course, it's a dry heat there. 😉