A meeting at the Merseyside Maritime Museum open to anyone interested in the tides and the port of Liverpool.
This meeting is organised by the National Oceanography Centre and the University of Liverpool, in association with the Centre for Port and Maritime History (University of Liverpool, Liverpool John Moores University and Merseyside Maritime Museum) and the Liverpool Institute for Sustainable Coasts and Oceans (National Oceanography Centre, University of Liverpool and Liverpool John Moores University).
This meeting marks the 100th anniversary of the world-famous Liverpool Tidal Institute, founded at Liverpool University in 1919 before moving to Bidston Observatory on the Wirral.
Click here for more information, including agenda, list of speakers and how to book.
This is the text of a speech given by Sylvia Asquith on 27th September 2017 at the Foundation of Art and Creative Technology (FACT) during the New Observatory Exhibition. Sylvia’s speech was followed by the screening of a short film by Yu-Chen Wang entitled “I wish to communicate with you”.
Good evening ladies and gentlemen.
My name is Sylvia Asquith and I joined the Bidston Observatory staff in February 1947 as Sylvia Brooks. It was a long time ago but I well remember those early days.
The connection between storm surges in the North Sea and the new British Nobel Laureate, Kazuo Ishiguro
Judith Wolf, October 2017
I only met Kazuo Ishiguro’s father once. In April 1981 we both attended a session of the 5th UK Geophysical Assembly at the University of Cambridge. I was in the throes of my PhD study and looking at the effect of wind gustiness on wind-driven currents in numerical models. In our session, on “Air-Sea Interaction” there were only three of us (the third being Ed Monahan, who worked on wind waves), and being the last session on the Friday afternoon, and rather peripheral to the main topics of the conference, there were only the three of us left there to listen to each other’s presentations and dutifully ask questions. Shizuo Ishiguro’s talk was entitled “Extreme surge predictions by the quasi uniform steady wind/pressure field method” (*); he was known to me by reputation, although by this time his work was something of an anachronism, as the world had moved on to digital computers. He had built an analogue computer to model North Sea storm surges and was employed, like myself, at the Institute of Oceanographic Sciences (IOS), but based at Wormley in Surrey, while I worked at Bidston Observatory in NW England.
This short film, by Andy Lane, Andy Heath and Craig Corbett, is part of the Tide and Time exhibition at the National Oceanography Centre, Liverpool. The exhibition showcases two tidal prediction machines – the Roberts-Légé and the Doodson-Légé. The film also explores the history of tidal science in Liverpool and its development as a port.
There is a lot of renewed interest in tide prediction machines and, after many years hidden away in storerooms, some of the machines made in the UK are on permanent display once again. Kelvin’s original 10-component machine is now part of the new Winton Gallery for Mathematics at the Science Museum in London alongside Ishiguro’s storm surge simulator. Two of the machines that were used at Bidston can now be seen at the National Oceanography Centre building in Brownlow Street in Liverpool.
As you may know from articles mentioned in the Resources section of this web site, the tide prediction machines were a way of simulating the tide in terms of its many harmonic components. Each component would be represented by an amplitude and phase lag, called the ‘harmonic constants’, and the machine, which can be considered as a sort of analogue computer, would be programmed to run by providing it with these constants. Of course, the constants would differ from port to port.
That raises the obvious question of where people like Arthur Doodson, and the other operators of the machines, got their constants from in the first place. This short article reviews the main characteristics of one of the machines (the so-called Doodson-Légé machine now on display at NOC) and then attempts to answer the question of how Doodson obtained the constants.
The exhibition – at the National Oceanography Centre in Liverpool – showcases some of the fascinating achievements made in the Liverpool area in understanding and predicting the tides. The highlights of the exhibition are the rare Roberts-Légé and Doodson-Légé tide prediction machines, extraordinary analogue computers that calculate the rise and fall of the ocean tide. See these beautifully intricate machines up and running at the only place in the world where you can see two of them together.
Research on Earth tides and ocean tide loading has an even longer history at Bidston Observatory than the work on ocean tides. This article gives a brief overview of the developments in these research areas following the measurements at Bidston in 1909 by John Milne, with particular emphasis on the contributions of the research groups at Bidston to the advances in these topics.
I joined IOS Bidston (as it was then) in October 1977. The validity of my appointment could be questioned as the appointment letter came from DB Crowder (the Bidston administrator) who left before I arrived.
It was a good time to join. There were about 80 staff in total, few enough to give a “family” atmosphere with the feeling that everyone knew everyone else. Several colleagues had been taken on during the early 1970s but it was still a time of expansion rather than otherwise. Scientists like myself had a fairly free hand to pursue promising lines of research within a fairly broad remit. I enjoyed a feeling of support from fellow scientists to do just this. Much of the funding came through a consortium of several government departments with an interest in our research. The negotiations were at some distance from most of the scientists who did not have to spend much time writing proposals, yet it was good to know of “user” interest in our work, always a characteristic of Bidston science. It was still possible to be “the” expert in a topic, a rarity today. I was lucky.
Most people know that the tide rises and falls periodically at the coast but not everyone is as aware of the periodic flood and ebb of tidal currents. These are of particular importance for mariners and need to be taken into account for navigation. Where currents become particularly strong, they can become known as a ‘tidal race’, which can be unnavigable at certain states of the tide.
Around the coast of the British Isles are many locations where a tidal race forms, usually in a constricted channel between two islands or an island and the mainland. In Scotland, between the islands of Jura and Scarba is the famous ‘Whirlpool of Corryvreckan’ – possibly the third largest whirlpool in the world (after Saltstraumen and Moskstraumen, off the coast of Norway). The Gulf of Corryvreckan, also called the Strait of Corryvreckan, is a narrow strait between the islands of Jura and Scarba, in Argyll and Bute, off the west coast of mainland Scotland.
One of the main objectives of the research at Bidston Observatory was to understand more about the dynamics of the ocean tides, that is to say, the physical reasons for why the tide propagates through the ocean as it is observed to do. Before the advent of digital computers, the only way to approach these questions was from basic mathematical perspectives, in which eminent scientists such as Pierre-Simon Laplace in France excelled in the 19th century, and in which Joseph Proudman at Bidston was an acknowledged expert in the 20th century.
Similarly, there has always been considerable interest in the reasons for large non-tidal changes in sea level, including in particular those which occur due to the ‘storm surges’ generated by strong winds and low air pressures in winter. For example, following the Thames floods of January 1928, Arthur Doodson at Bidston chaired a committee for London County Council that undertook a detailed study of the reasons for the storm surge that caused the flooding, and made recommendations for protecting the city in the future.