OCEAN WEATHER SHIPS
By SIR NELSON JOHNSON•
THE public first heard of the ocean weather ships last summer when the Secretary of State for Air performed the ceremony of naming the ' Weather Observer ' at London Docks. During the past few months the weather ships have been in the news three times. In October one of the American ships rescued the crew and passengers of a charter aircraft in mid-Atlantic ; on Christmas after- noon we heard a broadcast from the British ' Weather Observer,' which was then " on station " 40o miles west of Ireland ; and in the middle of January another of the British ships, the ' Weather Recorder,' rescued the crew of the Norwegian steamer Veni ' which had run on the rocks off the west coast of Scotland. The thinking man is beginning to seek a little more information about the weather ships. What are the real functions of these ships, how are they organised, and do other countries besides England and America provide such ships ? The answers to these questions will show that the weather ships afford a shining example of what can be achieved by international co-operation.
The primary duty of the weather ships is to provide meteorological reports from certain parts of the North Atlantic Ocean for the benefit of the forecasters of the meteorological services in northern America and western Europe. In making his weather forecasts, the fore- caster constructs a chart every few hours, showing the weather over an area which may extend from Morocco to Spitzbergen and from the Ural Mountains to the Pacific seaboard of North America. The movement and development of the pressure systems shown on this chart enable the forecaster to foresee the changes in weather at any place or along a particular air route. But while there are plenty of weather reports from the land areas, observations are received from the Atlantic Ocean only along the " lanes " followed by merchant shipping. Away from these shipping lanes are large blank areas within which a depression may be born undetected and upset the calculations of the unknowing forecaster. It may be noted in pass- ing that reports from the Atlantic are of particular importance to Great Britain because most of the weather systems in these latitudes travel from west to east. In other words, our weather for tomorrow is determined by the weather out over the Atlantic today. Reports from the ocean weather ships are probably of greatest immediate value in forecasting for transatlantic flying, but they also play an important part in the preparation of forecasts for all the other kinds of flying to and from the British Isles, and in making the forecasts issued to the B.B.C., the Press, the railways and the many other users of weather predictions.
The value to be derived from observations made in mid-Atlantic was realised by meteorologists before the war, and in 1938 the French Government fitted out the merchant vessel Carimare ' as a weather ship in the North Atlantic. About the same time the Germans had two ships performing similar functions on their trans-oceanic air routes, one in the North Atlantic and one in the South Atlantic. During the war, when wireless silence was imposed on convoys, Great Britain provided special weather ships to enable more accurate forecasts to be made for ferrying aircraft across the Atlantic and for the large-scale operations of the Royal Air Force over German- '' Director of the Meteorological Office. occupied Europe. Two of these ships were sunk by the enemy with the loss of many brave men. By 1945 the United States also had a number of similar vessels, but with the cessation of hostilities the American and British naval authorities necessarily called their ships in. But though the military justification for the ships had largely dis- appeared, the projected development of civil aviation made them nearly as essential as before.
Early in 1946 both the International Meteorological Organisation and the International Civil Aviation Organisation discussed the need for maintaining the weather ships, and the latter organisation pro- duced a scheme for establishing ships at thirteen positions on an international co-operative basis. An " Ocean Weather " Ship Con- ference was convened in London the following autumn, at which delegations from thirteen States were present, viz., Belgium, Canada, Denmark, France, Iceland, Ireland, Netherlands, Norway, Portugal, Spain, Sweden, United Kingdom and United States of America. Within eight days the conference had worked out a complete scheme. An international agreement was signed covering the administrative, financial and technical aspects. The United States assumed re- sponsibility for seven of the thirteen positions, and for an eighth jointly with Canada. On the European side, the United Kingdom undertook to provide ships for two stations, France for one, Belgium and the Netherlands for one jointly, whilst the last station was to be dealt with by a joint effort of Norway, Sweden and the United Kingdom. Ireland and Portugal made financial donations towards the cost of operating the scheme. It requires two ships to keep a station continuously manned, and in the case of the Belgian- Netherlands station each country decided to provide and operate orre ship according to a mutually agreed time-table. On the other hand, the Scandinavian arrangement provided for the United Kingdom to supply the two ships and equipment, for Sweden to help financially and for Norway to man and operate the ships. The conference agreed that all the ships should form part of the meteorological services of their respective countries, and that the meteorological observations should be made on the ships in accordance with the standard international procedures laid down by the International Meteorological Organisation. In spite of the difficulties with which every country is having to contend, there are now in operation four American ships, three British; two French, one Belgian, one Dutch and one Canadian.
All the ships are fully equipped with the most up-to-date meteorological instruments. The ordinary observations of air temperature, humidity, cloud, wind, visibility and roughness of the sea are made every three hours, day and night. In addition, the new techniques of radio-sonde and radar are brought into use every six hours to measure the stability of the atmosphere and the winds aloft. These measurements are extended well into the strato- sphere, and constitute one of the most valuable features in the observing programme. The reason for this lies in the fact that the forecaster is no longer content with a weather chart depicting the conditions at the surface. He now wants a series of charts drawn for four or five different levels from the surface to well into the stratosphere. These give him a three-dimensional picture of the atmosphere, as compared with the older two-dimensional representa- tion, and enable him to see and understand what developments are taking place in the cyclones and other dymmical systems which he has to study. This is a new aspect of the science of weather fore- casting which may lead to important results. From this point of view alone, therefore, the advent of the weather ships is a significant step forward.
The role of the ships is not confined to reporting the weather, but includes two other functions. Although not anchored, the ships maintain nearly constant positions, which they frequently check by various means. They are thus able to act as radio beacons to trans- atlantic aircraft which can check their navigation and adjust their courses accordingly. Aircraft can also ask the ships for the latest information about the upper winds and other conditions on their route ahead. The third function of the weather ships is to go to the rescue of aircraft or ships in distress, for which purpose they carry special equipment. Although it was generally expected that the ships would only occasionally be called upon to exercise this function, two cases have already occurred this winter. Whilst the creation of the service appears primarily as a new technical venture, it should be viewed equally as a lesson in international co-operation. In a world that is becoming sceptical whether anything can be achieved by international machinery, the weather ships prove that success, both speedy and effective, can be looked for when those concerned have a single aim and resolve to achieve it.