 Tidal Surges - criteria ?
What are the criteria for large tidal excesses over astronomical predicted
tides for the area around the UK ?
Deep depression in the North Atlantic, yes.
But for low barometric pressure induced sea level raising would it not be
the area of sea affected being a major factor.
Comparing 2 scenarios
1/ central low of 960mBar but 990 mbar isobar of 100 mile diameter
2/ central low of 960mBar but 990 mbar isobar of 500 mile diameter
Would not 2/ create much more sea uplift than 1/? , so much greater volume
to potentially come ashore, then magnifying the height anomaly by
shelving/funneling.
Is the timing significant? or is the effect independent of whether the
principal (nearest the UK ) surge formation depression is, locally to
itself, passing at high tide or low tide.
From BODC data the highest surge to the South Coast for years 1992 to 2002
occured 30 October 2002 with maximum excess (residual) at Portsmouth of 1.12
metres, but not near local high tide so no flooding consequnces.
The N Atlantic synoptic charts for the preceeding time window shows a double
coupled low , one over the Shetlands and the other SW Iceland with a huge
sea area contained within the 992mBar isobar stretching 45 degrees of
longitude in the line of the 2 lows and a more normal 10 degrees of latitude
span.
Anyone know of a meteorological+oceanographic analysis of the 1953, 31
January Canvey Island/Dutch inundation?
| 
