Curious met phenomina.....

[FlyingForFun]

Something which has been niggling at the back of my mind for a while now (in fact, since I moved up to Blackpool and started flying by the coast regularly). You can tell by the fact that it's taken me a year to ask the question that it's not that important, but......

Flying by the coast on a hazy day (8-10km viz, or maybe slightly more), a couple of miles inland, and heading towards the coast. Whilst still a little way from the coast, there is no visible horizon - the sea and the sky just merge into one. But as you get closer and closer to the coast, the horizon becomes more and more clear, with a very defniite colour change between the sea and the sky. The difference in colour gets more marked the closer to the coast you get.

Does anyone have any explaination, other than optical illusion? I can not think of any reason why this should be the case, but I have seen it dozens, probably getting on for hundreds, of times.

Or, alternatively, does anyone have any other strange unexplainable met phenomina to keep the trivia-masters amused until they can go flying again?

FFF
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[High Wing Drifter]

I guess that at a distance, the haze dilutes the colour of the sea, making it difficult to differentiate from the sky. As you get closer with a subsequently lower haze effect, the sea stands out more.

[boomerangben]

Could it be that the beach/surf generates the haze which subsequently drifts inland on a sea breeze? As you approach the coast, there is less haze to see through, hence the clearing viz?

[bar shaker]

Cool sea breeze meets warm moist air mass over land, creating a curtain of haze.

When pilot can see past the top of the curtain, the horizon appears clear again.

[FlyingForFun]

HWD, I don't think that's true, because you never get closer to the horizon, only to the coast. I think boomerangben's and bar shaker's theory sounds more plausible.....

FFF
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[High Wing Drifter]

FFF,

HWD, I don't think that's true, because you never get closer to the horizon, only to the coast. I think boomerangben's and bar shaker's theory sounds more plausible.....

Well actually, my brief explanation isn't incompatible with Bar Shakers. He is saying exactly the same thig, the viz over the land is less than over the sea. He just provides a reason for it.

Although our conclusions are the same, my reasoning isn't. Visibility over the sea will be better than over the land where the particals trapped in the air will be more dense where the prevailing wind is landward (as it is in your neck of the woods) in addition to the costal sea breeze (this time of year). Therefore, it wouldn't be wreckless to say that possibly the collection of haze inducing partials is less dense over the sea.

I think I understand that Bar Shaker's comment is referring to the condensation of moisture. The sea breeze is created by the convecting air over the land being replaced by cold (relatively) sea air. This sea air will only get warmer as it comes in over the hot land, reducing RH, not increasing it. Furthermore, that warming sea air will convect (it can't convect if it is cold, unless due to high ground) and will be taken back out to sea to cool. As the convecting air cools as it assends it flops over the top and back toward the sea. This condensation can sometimes be seen as a line of 'roll' cloud along the coast. As my understanding stands at this present time, I don't believe it would result in the effect you describe.

I wonder if the sea breeze process also effectively traps haze particals ove r the land?

[turn right heading 365]

Surf? Blackpool?

[bcfc]

Recommend you read Pilot's Weather. Full of useful stuff.