A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Nansen question
From: George Huxtable
Date: 2009 Dec 12, 15:23 -0000
From: George Huxtable
Date: 2009 Dec 12, 15:23 -0000
There's an alternative to explaining Ekman transport. As with many other topics, it's been discussed previously on this list (well, on its predecessor, actually- Nav-L) If you look at the exchanges around 19 Jan 2005, you will find discussions of Ekman spiral, including some particularly wise words emanating from "Gadus"; actually the remarkably well-informed Trevor Kenchington. I would be interested to read Nansen's words on that topic. How did you get to them? Yours, George. contact George Huxtable, at email@example.com or at +44 1865 820222 (from UK, 01865 820222) or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. ----- Original Message ----- From: "Apache Runner"
To: Sent: Saturday, December 12, 2009 2:47 PM Subject: Re: [NavList 11097] Nansen question | Thanks, George. In the "Some Results..." article, there is the first | actual mention of the idea that led to Ekman transport. It took a bit of | digging to get there. | | The Ekman theory is a reasonable approximation, but it leaves out all sorts | of issues like the effect of turbulence etc. It goes a long way to | explaining the structure of gyres in oceanic currents, but it's not the full | story. | | If anyone's interested, I can post the quote from Nansen, but then I'd have | to explain Ekman transport....which might be more than you want. | | Thanks, | | John Huth | | | On Fri, Dec 11, 2009 at 7:00 AM, George Huxtable wrote: | | > A follow-up to my earlier posting, which attempted to answer Apache | > Runner's | > question about the origin of the Ekman theory of wind drift. | > | > I suggested that Nansen's publication "Some results of the Norwegian Arctic | > Expredition 1893-96" might be productive, but a look in Abebooks tells me | > that slim volume is just reprinted from an item in the Journal of the Royal | > Geographical Society, presumably for 1897. So that may be findable in an | > academic library. | > | > But I've also discovered that the results were gathered into a series of | > (at | > least) 6 volumes, "The Norwegian North Polar Expedition 1893-1896 | > Scientific | > Results Vol 1", etc, edited by Nansen (presumably in English). These were | > reprinted by Greenwood Press, New York, around 1970, so should be available | > in libraries. And I see that Ekman made at least one contribution to that | > series (on "Dead-water", in vol 3). | > | > I remember learning about the Ekman theory, in an oceanography course in | > the | > early 1950s (and being a bit sceptical). | > | > George. | > | > contact George Huxtable, at firstname.lastname@example.org | > or at +44 1865 820222 (from UK, 01865 820222) | > or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. | > ----- Original Message ----- | > From: "George Huxtable" | > To: | > Sent: Friday, December 11, 2009 12:47 AM | > Subject: Re: [NavList 11079] Nansen question | > | > | > | Yes, it was on the Fram expedition of 1893-96, , when Nansen made the | > | observation sthat led to the Ekman spiral, according to "The Oceans", | > | Sverdup, Johnson, and Fleming (1942), page 492. | > | | > | I have the two volumes of Nansen's "Furthest North", but a very-quick | > scan | > | from the index has only led to passages which seem to imply that ice was | > | drifting straight downwind, not at an angle. But Nansen says that further | > | publications will follow with the scientific details. He later published | > | which might be | > | productive, but I don't know it. | > | | > | George | > | | > | contact George Huxtable, at email@example.com | > | or at +44 1865 820222 (from UK, 01865 820222) | > | or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK. | > | ----- Original Message ----- | > | From: "Apache Runner" | > | To: | > | Sent: Thursday, December 10, 2009 11:35 PM | > | Subject: [NavList 11077] Nansen question | > | | > | | > || Does anyone know the original publication of Nansen's work that led to | > the | > || Eckman theory of currents? | > || | > || As I recall, he noticed that icebergs moved at some angle (30-40 | > degrees) | > || with respect to the direction that the wind was blowing them and deduced | > || that it was due to the combination of the wind and the Coriolis effect. | > || That observation was the basis of the Eckman theory. I'm curious about | > | the | > || expedition this was sighted on. I think it was the famous Polar drift | > | of | > || the Fram, but I'm not sure. I don't recall seeing it written in | > Furthest | > || North (quite a tale, too), so I'm assuming it was a scientific | > | publication. | > || | > || Anyone know? | > || | > || -- | > || NavList message boards: www.fer3.com/arc | > || Or post by email to: NavList@fer3.com | > || To unsubscribe, email NavListfirstname.lastname@example.org | > | | > | -- | > | NavList message boards: www.fer3.com/arc | > | Or post by email to: NavList@fer3.com | > | To unsubscribe, email NavListemail@example.com | > | > -- | > NavList message boards: www.fer3.com/arc | > Or post by email to: NavList@fer3.com | > To unsubscribe, email NavListfirstname.lastname@example.org | > | | -- | NavList message boards: www.fer3.com/arc | Or post by email to: NavList@fer3.com | To unsubscribe, email NavListemail@example.com -- NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To unsubscribe, email NavListfirstname.lastname@example.org