City of London Training Site

We asked experts [Proudman Oceanographic Laboratory, Bidston Observatory] on the web, who said and we quote

"Monthly mean sea level values from tide gauges at the coasts of the North Sea are compared with the monthly means from an operational tide-surge numerical model for the time period 1955–1984. The model describes most of the variability at all frequencies except the annual. Most of the energy around the pole tide frequency is also reproduce by the model and since its tidal forcing does not include the equilibrium pole tide frequencies it is concluded that the deviations from the equilibrium pole tide are of meteorological origin. The east–west wind stress component is found to be energetic at this frequency thus providing the meteorological forcing. The annual cycle due to steric effects is also estimated. The meteorological correction modifies the determined sea-level secular trends by up to 0.8 mm/yr for this 30 year period for stations in the eastern North Sea."

We decided to get a definition of POLE TIDE from www.nature.com

If you fail to get proper trigonometric intelligence below,

it'll be your computer's security system having a bad day!

THE annual variation in latitude¹ causes a disturbance in the gravitational potential with an amplitude: U = a ^{2 2} m sin cos = 880 sin cos cm.² sec.^-2 where a is the radius and the angular velocity of the Earth, and where m is the angular displacement of the pole along the meridian of a station located at co-latitude . For the annual term, Jeffreys¹ obtained m 0.084" = 4.07 10^-7 radians, and the numerical value 880 follows from this. In comparison, the equilibrium tide S _a associated with the annual variation of the heliocentric distance has a potential²: 472( - cos²)cm.² sec.^-2 The mean square values, are equal to (321 cm.² sec.^-2)² for the 'pole tide', and (141 cm.² sec.^-2)² for the S _a, so that the pole tide is larger. Yet it appears to have been overlooked. This simply means that there is a larger effect from a movement, north or south, by 10 ft. than from a variation by 2 per cent of the Sun's distance.

http://www.freewebs.com/kjtraining/tidalebbflow.htm

Tides are what make the River interesting. The ever changing ebb and flow, the bi-monthly neaps and springs, the unpredictability of tidal 'predictions', the constantly changing state of the river and its shoreline are baffling to some, fascinating to others but to us they are simply a fact of life. On a grand scale the tides are the living manifestation that the earth is a living organism and the tides are her gentle breathing. Robbie Burns noted wryly that 'nae mon can tether tide nor time'. The wee Scot had a point. It behoves the sensible to allow the tides to work for him by knowing what to expect from them and allowing for it. The actual height of tide at London Bridge has a maximum prediction of 7.4m but has been noted above 8. [citation needed]

WHAT IS THE HEIGHT OF TIDE BELOW AND IS IT MAKING OR EBBING?

Yer man is a right potential candidate for chart work, H+S and tide prediction.