New Posts New Posts RSS Feed: Can Meteorology win races?
  FAQ FAQ  Forum Search   Register Register  Login Login

Can Meteorology win races?

 Post Reply Post Reply Page  <123
Author
Mike B View Drop Down
Newbie
Newbie


Joined: 12 Feb 06
Online Status: Offline
Posts: 8
Post Options Post Options   Quote Mike B Quote  Post ReplyReply Direct Link To This Post Posted: 21 Nov 07 at 8:41pm

I'm a bit amazed to find the chain I started in May still going.

 

M A Rand says there is 'very good data to support Houghton and Campbell's conclusions although you may not be privy to it'. Possibly, but I have met David Houghton several times and he's never told me about it.

 

In fact the problem is worse than their having no proof, there is actually a lot of research published in peer-review meteorological journals which contradicts them. If they’re right then literally decades of Met Office data and research projects around the world would have to be faulty and I just don't buy that. So far as I can see this wind bends at coastlines stuff from Houghton and Campbell is just wishful thinking and hocus-pocus.

 

Of course there may be particular places or times where there is some consistent behaviour but nothing universal but that’s not the issue here.

Back to Top
Pierre View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 15 Mar 04
Location: United Kingdom
Online Status: Offline
Posts: 1488
Post Options Post Options   Quote Pierre Quote  Post ReplyReply Direct Link To This Post Posted: 29 Nov 07 at 11:05am

Well looking at the meteorology for this coming Sunday, (2nd December), I'm glad I'm not in the boat insurance game. It looks a tab breezy down my way.

 

Back to Top
Black no sugar View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 04 Dec 04
Location: Somewhere between Brighton and Lancing
Online Status: Offline
Posts: 3941
Post Options Post Options   Quote Black no sugar Quote  Post ReplyReply Direct Link To This Post Posted: 29 Nov 07 at 11:17am

Same here! Force 8 to 9 on the Greenwich light vessel and the animation in Magic Seaweed is very colourful indeed.

He Who Must Be Obeyed says it's my turn to sail...  

Back to Top
Pierre View Drop Down
Really should get out more
Really should get out more
Avatar

Joined: 15 Mar 04
Location: United Kingdom
Online Status: Offline
Posts: 1488
Post Options Post Options   Quote Pierre Quote  Post ReplyReply Direct Link To This Post Posted: 29 Nov 07 at 11:20am

I'll lend you an Oppy Isa.

 

Back to Top
usa1971 View Drop Down
Newbie
Newbie


Joined: 06 Dec 07
Online Status: Offline
Posts: 2
Post Options Post Options   Quote usa1971 Quote  Post ReplyReply Direct Link To This Post Posted: 06 Dec 07 at 10:33pm
Please have a look at this research:  http://www.coriolis-legi.org/PUBLIS/Orretal2005_Weather.pdf.  It appears to describe the reasons for wind bending perpendicular to shore.
Back to Top
Mike B View Drop Down
Newbie
Newbie


Joined: 12 Feb 06
Online Status: Offline
Posts: 8
Post Options Post Options   Quote Mike B Quote  Post ReplyReply Direct Link To This Post Posted: 13 Dec 07 at 8:17pm

Thanks, interesting but I've seen this paper before. 

 

Even if this work did support Houghton and Campbell it would be irrelevent because offshore winds bending the 'wrong way' are measured by professionals pretty much as often as those going the 'right way'.

 

If you want to look at some more research go to the UK National Met Library via the UK Met O website. You will find a lot of research contradicting H and C and non by them, or anyone else, in support. A good one to look for is by PE Francis in 1970 who looked at a decade of offshore winds on the East Coast of the UK, roughly as many went left as right. Also use the search engine to find Gryning et al 'The Oresund experiment'. This was a major study of wind passing land-sea boundaries on the Danish coast, lots of balloons, data buoys etc. Again H and C are just plain wrong. There are more.

 

As regards your article, the authors talk about different mechanisms pushing the wind different ways. Right at the beginning Fig 1 shows an onshore wind (wrong way for us but the physics is the same in reverse) with it bending either way according to the mechanism that dominates. They are also talking about scales much larger than those H and C refer to, typically 10s of kilometres.

 

I've met David Houghton many times (he was personnel manager in the Met Office 25 or so years ago and he actually recruited me). For what it is worth I'll e-mail him, and Fiona C, pointing out this forum and see if they can be bothered to make their case.

Back to Top
usa1971 View Drop Down
Newbie
Newbie


Joined: 06 Dec 07
Online Status: Offline
Posts: 2
Post Options Post Options   Quote usa1971 Quote  Post ReplyReply Direct Link To This Post Posted: 14 Dec 07 at 5:36pm

I would love to hear Houghton and Campbell, or any of the other writers on these issues chime in here.  As far as the wind always veering as it comes offshore, the new edition of Wind Strategy does state that this effect is tempered by topography as well as the temperature of the air, land and water.  Stuart Walker, the American sailor and writer on wind strategy issues tends to side with you that veering of offshore winds occurs only rarely.

The article by Orr, et.al. that I linked to seems to suggest that all angled offshore winds leave the shore more perpendicular to the shoreline.  This is stated in many books and articles on sailing strategy.  What is your take on this?

Another interesting debate between wind strategists is whether convergence or divergence (when the wind is parallel to the shoreline) brings stronger air.  Houghton and Campbell write that convergence creates better wind while Walker writes the opposite.  The Orr article, if I am reading it correctly (and I'm no meterologist) seems to state that both convergence and divergence create more wind.  Do you have a take on this?  This is also discussed online at http://forums.sailingworld.com/showthread.php?p=4117.

Thanks for the links to the other articles.  Is there a way to access the actual documents online?

Back to Top
Mike B View Drop Down
Newbie
Newbie


Joined: 12 Feb 06
Online Status: Offline
Posts: 8
Post Options Post Options   Quote Mike B Quote  Post ReplyReply Direct Link To This Post Posted: 22 Dec 07 at 3:39pm

I've pointed out this forum to Houghton and Campbell, let's see if they turn up.

 

I didn't see any evidence for wind crossing the coast more nearly at right angles in Orr et al. and I'm not aware of any evidence for this or a convincing mechanism. It's certainly a common idea though. I recall speaking to a successful Finn sailor many years ago who had written about this in one of his books (why does every expert yachtsman think they are an expert meteorologist? I don't see many meteorologists laying down the law on sail trim or interpreting the race rules). It turned out he had experienced wind crossing the coast perpendicular at one event, once. He was quite happy to change his views. This is something that would be easy enough to prove so I suggest the onus of proof is on its supporters.

 

As regards convergence and stronger wind, strictly speaking convergence just means more air going into a region than leaving it. This is looking in two dimensions so convergence tends to be associated with ascending air (otherwise the air just squeezes up which it has a limited capability of). There is no fundamental reason to expect either convergence or divergence to automatically be associated with an increase in wind. However I would myself expect the kind of along coast convergence discussed by HandC to result in stronger wind. I'm sceptical about their rules for forecasting it though and I doubt it works as they describe on the sort of scales they describe.

 

As regards the documents I mentioned, I'm afraid I don't think they are available on line, the older one by Francis may not have been produced in e-form at all, but hopefully a major library could get you copies. Full references are as follows which might help.

 

Francis, P.E. (1970). The effect of changes of atmospheric stability and surface roughness on offshore winds over the East Coast of Britain. Meteo. Mag. 99, pp. 130-137.

 

Doran, J.C.,Gryning, S.-E. Joffre, S. (1987) The Oresund experiment - wind and temperature structure over a land-water-land area. Boundary-Layer Meteorology, VOL. 41 NO. 1-4, 1987, pp. 309-318.

 

If you're also interested in convergence you might want to look at one of mine: -

 

Brettle, M.J. (1989). Sea temperatures and coastal winds.Weather 44 no.6. 249-256.

 

 

Thanks for the link to the other forum. Its good to see these things discussed, again, as you imply the 'gurus' themselves are conspicuous by their absence.

Back to Top
 Post Reply Post Reply Page  <123

Forum Jump Forum Permissions View Drop Down

Bulletin Board Software by Web Wiz Forums® version 9.665y
Copyright ©2001-2010 Web Wiz