NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Global oceanic tides, was: Navigating Around Hills and Dips in the Ocean
From: Trevor Kenchington
Date: 2003 Aug 15, 22:49 -0300
From: Trevor Kenchington
Date: 2003 Aug 15, 22:49 -0300
George Huxtable wrote, after much snipping: > Because of the inertia of the immense water-masses involved, together with > the obstruction caused by the continents (which restrict free flow from one > ocean basin to another) the ocean surface can't, anywhere near, respond to > these forces in the necessary time. Instead, the water swirls and surges > around the ocean basins, in a pattern that's so complex that it defies > calculation. While computationally daunting, in the last ten years, cotidal charts for the world ocean have been calculated from the astronomic tide generating forces and the shapes of the ocean basins -- charts that seem to match quite well with empirical observations. Back when I was an oceanography student (nearly 30 years now) it was quite impossible. The first realistic tidal model I encountered (for part of the Tasman Sea) dated from the mid-1980s. By the mid- to late-1990s, it was possible to do the whole ocean. Trevor Kenchington -- Trevor J. Kenchington PhD Gadus@iStar.ca Gadus Associates, Office(902) 889-9250 R.R.#1, Musquodoboit Harbour, Fax (902) 889-9251 Nova Scotia B0J 2L0, CANADA Home (902) 889-3555 Science Serving the Fisheries http://home.istar.ca/~gadus