Superb visibility

[richardh1905]

Yesterday morning, whilst driving over the brow of a hill in East Mainland, Orkney, I saw a sight that took my breath away - all the mountains in the North of Scotland laid out in front of me; jewels in a crown.


From E to W - Scaraben, Maiden Pap, Morvern, then a gap to what I think was Ben Griam Beg, a bit further in the distance, majestic Ben Klibreck, multi-topped Ben Loyal, Ben Hope, then a jumble of hills that I later identified as Foinaven, Cranstackie and Ben Spionnaid, and I think in the far distance Cape Wrath. Enough to make the heart sing!


Distance to Foinaven was 80 miles, as the crow flies.

[sunnydale]

Sounds fab Richard   There’s nothing like a good view to lift the spirits

[BuzyG]

Those days are the ones we remember so vividly.  What a view that must have been.

I still recall taking off from Exeter Air port once and looking to the east. You could see past Portland past Portsmouth and IoW pretty much the whole channel coast to Beachy head.  Never seen much past Portland on any other flight out of there. Some days are just so clear.

Does any one know what makes the difference?

[richardh1905]

Lack of dust, pollutants and water vapour in the air. Seems the best days are often after a cold front has passed through, still breezy, off the sea.

[Bigfoot_Mike]

The best visibility I have experienced has been in the winter in Scotland. When the pressure is high, the temperature is low and there is almost no moisture in the air, vision is much sharper. I have seen this in Aberdeen, on a flight from Aberdeen and from the top of Ben Wyvis.

[Dyffryn Ardudwy]

Two years ago, Nov 12th, i was walking over the Great Orme with my cousin.
The views on the horizon were outstanding, the best ive ever seen.

The Cumbrian Hills were crystal clear, but it was the land that you could see behind Cumbria that really stood out.
It might have been the mountains of the Inner Hebrides, or some other part of the Scottish mainland on the West coast.

Cumbria is visible quite often, after a spell of heavy rain, but seeing areas of land way beyond Cumbria was a real treat.

[ninthace]

Sure it wasn't the Isle of Man?  On a clear day from our home in Anglesey we could see Ireland, the IoM and the Cumbrian Hills.

[sparnel]

Although I've never myself seen it, I've heard it said that Snowdon can be seen from The Merrick in Southern Scotland.....that's some distance!

[ninthace]

It believe it is a theoretical rather than an actual possibility. From Wiki: the 144-mile (232 km) view between Merrick and Snowdon is the longest line of sight in the British Isles [1], but for geometrical reasons Merrick would be very difficult to observe from Snowdon

[richardh1905]

I can remember a super clear day on the Great Orme. Pennines, Cumbrian Fells, Isle of Man and the Mourne mountains all clearly visible.

[buryman]

It believe it is a theoretical rather than an actual possibility. From Wiki: the 144-mile (232 km) view between Merrick and Snowdon is the longest line of sight in the British Isles [1], but for geometrical reasons Merrick would be very difficult to observe from Snowdon

    Light does not behave differently when going north rather than south.

[ninthace]

    Light does not behave differently when going north rather than south.

I do not understand the point you are making.  The issue, I suspect, is that Lamachan Hill at 717m is directly in the way making it hard to distinguish the summit of Merrick at 843 m some 8.5km  behind it when viewed from 232 km away.

[GnP]

A sight that gave me a thrill was walking along Graig Fan Ddu ridge in the Brecon Beacons, knowing that the climbs of the four peaks, Corn du, Pen Y Fan, Cribyn & Fan Y big were done. I was relaxed and looked back over my left shoulder towards them. It was a clear sunny day, & the sight totally thrilled me. It was my first time up there..

 I have been many times since but for me, a townie.... it lifted my spirits sky high that day... They are not huge mountains or anywhere near, but I fell in love with the area....the peaks and the valleys. The rivers and waterfalls are beautiful and my camera is with me every time. !  

[ninthace]

Anyone wanting to know what can be seen from where will find this website is useful: http://www.ringbell.co.uk/info/hdist.htm


Knowing the height of the two points in question you can calculate how far away their respective horizons are.  Add the two horizons together.  If the distance between between the two points is less than the combined horizons then the two points are theoretically visible to each other if the weather and intervening geography allows it.



Example:
Summit of Snowdon: 1085m gives an horizon at 117.7km.
Summit of Merrick:  843m gives an horizon at 103.7
Combined horizon distance - 221.4 km
The combined horizon distance is less than the 232km between the two hills.  However, in extremis, atmospheric refraction extends the line of sight slightly over the horizon so it may just be possible to see one hill from the other if the conditions are propitious.  See https://www.timeanddate.com/astronomy/refraction.html for more information.

[buryman]

I do not understand the point you are making.  The issue, I suspect, is that Lamachan Hill at 717m is directly in the way making it hard to distinguish the summit of Merrick at 843 m some 8.5km  behind it when viewed from 232 km away.

   I take your point. Thanks for the carification.