The growth of marine meteorology—a major support programme for the World Weather Watch
By R. J. Shearman
This article appeared in the January 2003 WMO Bulletin
At the time of the First International Meteorological Conference in Brussels in August 1853, a number of major maritime nations had been recording and exchanging weather information for several years. Lieutenant Matthew Maury of the US Navy was the driving force behind the conference, and he was also respected for his studies of ocean currents and winds. He can be said to be the founder of marine meteorology, operational oceanography and the international cooperation, that ultimately led to WMO and the Intergovernmental Oceanographic Commission (IOC) of UNESCO.
Development of a European Meteorological Observing Network was spurred on by the loss of 38 French, English and Turkish ships engaged in the Crimea. Urbain Le Verrier, Head of the Paris Observatory, investigated the Crimean storm, collecting observations from across Europe. He also proposed to the French Government, shocked by the wreck of the Semillante and the loss of 700 sailors and soldiers in 1855, that the newly invented electric telegraph be used to transmit observations. This was a first tiny step on the road to the Global Telecommunication System. Although the ability to hindcast storms was demonstrated, little had been done to predict weather, although empirical relationships were available, such as that published by Buys-Ballot in 1857.
In the United Kingdom, Admiral Fitzroy, of the Beagle and Charles Darwin fame, became the first Director of the Meteorological Service and developed an observation collection and forecast warning system for ships at anchor. He proceeded to publish his forecasts in the press and developed and published forecasting rules. His attempts to meet the needs of customers were in the best tradition of marine meteorology.
International cooperation continued, leading in 1905 to the formal creation of the International Meteorological Organization (IMO). However, there was little development in marine meteorology because ships at sea could not communicate over long distances in real-time, and interest in climatology had waned as sail gave way to steam ships. The advent of wireless telegraphy heralded further development of the marine observing system.
Two notable events were the decision in 1907 to oblige all ships to be fitted with wireless telegraphy equipment and to transmit observations to shore, and the creation of a Technical Commission on Maritime Meteorology.
As wireless telegraphy improved, the collection of data over longer distances became possible, and the oceans were better covered by observations. By the late 1930s, the growth of transatlantic aviation, using aircraft that still flew at a low level and were vulnerable to adverse weather, had led to the concept of the dedicated weathership to fill gaps in the observing networks at sea. The needs of air and sea transport between the USA and Europe during the Second World War led to the expansion of these stations and a network that endured into the 1980s, and is still represented by one surviving Norwegian ship. At the same time, weather forecasting capability steadily improved.
The Commission for Marine Meteorology
In 1952, the Commission for Maritime (later Marine) Meteorology (CMM) met under the auspices of the newly created WMO. It was to meet approximately every four years for the next 45 years. The major concerns were those that have been addressed by CMM ever since notably:
Much time was devoted to discussing measurement problems and the measurement of rainfall at sea was addressed in some detail. The requirement came from operational needs related to cargo ventilation, and was discussed at several subsequent CMM sessions. By CMM-IV (1964), trials of raingauges were underway, as well as discussions of the use of visual estimates and the effect on 3 cm radar. No successful technique was identified and the requirement had decreased due to changing cargo practices. However, the subject returned in 1981 at CMM-VIII, in the context of climate research, and a rapporteur was appointed. Little progress was made, and the problem remains, although remote-sensing now offers a solution.
The 1952 meeting took the first steps towards assembling a climatological database by arranging for Members to cooperate in exchanging data. The data were required in connection with avoiding damage to goods during carriage at sea. There was concern regarding the sparsity of data in the Southern Ocean, and a cipher system was devised to allow whaling ships to transmit observations without revealing their all-important position
By the early 1960s there was clear evidence of the foresight of the founder members of CMM in that all the themes that would dominate the work programmes for the next 30 years had been identified and discussed to some extent.
Broadly these were:
There was clear evidence from the earliest days of the crosscutting issue of physical oceanography and oceanographic services.
Marine meteorological services
Until 1968, marine meteorological services were mainly determined by the needs of the professional mariner and particularly the fishing industry. Most of the work was motivated by improving safety at sea. For example, there was a major effort regarding ice accretion on ships as a consequence of fishing losses. There was also recognition of the economic benefits to be gained by forecasting sea-surface temperature more accurately for commercial fishing. At CMM-III (1960), the need to forecast “state of sea” from meteorological data and the urgent requirement for research aimed at extending weather and wave forecasts were both recognized. The shipping industry had begun to accept the benefit of embryonic ship-routeing services and it was clear that these should be developed on a more secure scientific footing. As part of the planning for the WWW, CMM was urged to consider the requirements of a wider range of customers and there was a determined move to integrate all the activities of CMM much more closely with the WWW.
The importance of storm surges to some Members was first mentioned at CMM-V with proposals to institute a warning service: the vulnerability of some coastal communities and activities had been recognized.
Throughout the 1970s a vigorous and demanding offshore oil industry moved into deeper and less hospitable waters. The investment was large and the industry expected specialized meteorological services in both the design and implementation phases of these projects.
By 1980, the range of service users had expanded to the extent that CMM's work was divided into two somewhat disproportionate areas:
Throughout the next decade,much was done to provide guidance on products intended for these areas, and to address problems. There was also increasing awareness of the need to seek users’ views, with a survey of ship’s masters conducted in 1981, and becoming a regular task of each intersessional period thereafter.
A closer relationship was developed with professional bodies representing user industries, notably the International Chamber of Shipping, International Federation of Ship Masters, the Oil Industry Exploration and Production Forum, and of course the International Maritime Organization.
The provision of services to maritime customers had always been critically dependent on communications. The development of radio and radio-facsimile provided a more flexible medium for the dissemination of meteorological products. The first weather maps had been transmitted by radio-facsimile in 1930, but it was only in 1960 that CMM originated a formal recommendation to encourage Members to increase such services and to attempt to convince ship operators to universally fit such equipment.
CMM has always had a remit to agree the content, areal coverage and production/dissemination of marine meteorological warnings and forecasts. Individual Members agreed to accept responsibility for particular elements of the service, with revisions achieved by negotiation. Standard symbols and nomenclature were similarly agreed. It was recognized in the early 1970s that satellite-based communications would bring a revolution in the provision of services. In particular, the inauguration of the INMARSAT network in 1982 was a major step forward. WMO engaged in early discussions with INMARSAT to develop the potential of the system for marine meteorological services.
Marine observations and data collection
The main component of the high-seas observing system is still the Voluntary Observing Ship (VOS) equipped with fairly basic sensors to measure air and sea temperature, pressure and sometimes wind. The other meteorological parameters, i.e. cloud, visibility, weather and wave or state of sea are provided by visual estimate from a ship officer. There has been little change in this situation throughout the lifetime of CMM.
The requirement for in situ observations from mobile ships was re-affirmed in the WWW plan, circa 1970, together with a call for a 25 per cent increase in numbers. However, as ships have increased in size, numbers have decreased although this is offset to some extent by the fact that modern vessels spend rather more time at sea than their predecessors. Despite the significant advances in space-based and other remote-sensing, ship observations remain an important source of in situ “ground truth” data.
The importance of Port Meteorological Officers (PMO) in encouraging and training voluntary observers, and recruiting their services, was recognized by CMM-II in 1956. Their role has been steadily enhanced and they became a formalized part of the data-quality feedback loop in 1990.
As shipboard communications were automated, and radio operators became fewer, timely transmission of observations became an issue and some effort was devoted to automation of the coding and transmission process. It was recognized, as early as 1960, that coding the observation was error-prone, and a “slide rule coder” was developed for use by fishermen and whalers. Efforts were also made to simplify the codes. Further successful attempts were made in the late 1980s to automate the process and software is now available for use on a shipboard PC linked to satellite communications. The system removes much of the potential for error, and also stores the data on magnetic media so that the meteorological logbook can be discontinued.
Until recently, the developments in automatic weather stations on land have not been carried through to mobile ships, although similar systems have been installed and operated on research vessels, light vessels, offshore platforms and moored meteorological buoys. The main obstacle has been the risk of losing the significant capital investment involved because merchant ships have changed ownership much more frequently in recent years. Thus there is a need for a system with a relatively small footprint, independent of the ship’s systems, so that it can be installed and removed in the few hours that modern ships are in port. In the last two years, a system adapted from data buoy technology, with its own integral GPS and satellite communications has been developed and used on Canadian VOSs in the Arctic. The increase in data coverage in these areas has been spectacular.
Container ship (2001) (Crown copyright)
The problems of instrument exposure, and even estimation of sea state, remain, particularly on large tankers, container ships or bulk carriers. In 1987, approximately 50 VOSs, all noted for good-quality data and reliable reporting, were recruited to a special observing project (VSOP-NA) lasting for three years. These ships were asked to complete much more detailed meteorological logbooks while transiting the North Atlantic, to record information regarding lading, cargo configuration and observing practices, all of which could be used to place the observations in the context of exposure at the time. In addition, plans of the ships and location of instrumentation were collated and archived. The data were analysed and a comprehensive report produced in 1991. It is now proposed to extend some of the findings to a larger subset of some 200 VOSs. The benefit is greatest for climatological studies, but greater concentration on observing practices will also assist synoptic meteorology.
The first session of CMM concluded that radiosonde observations from merchant ships were not practicable. Given the need for ground truth in support of satellite profile data, and the subsequent demise of the Ocean Weather Ships, it was fortunate that a number of countries persevered in attempting to solve the problems. By 1968, the United Kingdom, for example, was making regular balloon ascents from the Sugar Exporter, employing a trained meteorologist on board. The major difficulty encountered was transmitting the whole message via coastal radio stations.
These initiatives led, via containerized radiosonde ground stations and satellite communications to the Automated Shipboard Aerological Programme (ASAP) systems in use today. Twenty-three ASAP vessels were in operation in 2001, sponsored by eight Members, and a further vessel had been equipped that would ply from Europe to Australia as the first step in a Worldwide Recurring ASAP project (WRAP). Average burst heights of 21 km and a data-retrieval rate of 90 per cent are a significant achievement, given the problems of launching from the turbulent environment of a moving ship at sea.
An observing network based on voluntary merchant ships has the inherent limitation that they tend to follow trade routes. The tendency has increased in recent years as deep ocean vessels have become larger and ports of call relatively fewer. There are large areas of the oceans, particularly the Southern Ocean, that are devoid of data. However, even a relatively busy region such as the North Atlantic has areas that are between ship routes.
There was considerable discussion of the use of data buoys. Development of both moored and drifting buoys continued within a number of mainly research-orientated programmes. In particular, a great deal of experience was gained during FGGE. In 1985, a preliminary meeting was proposed with the objective of setting up a consortium under the joint sponsorship of WMO and IOC to proceed with the implementation of drifting buoy programmes. This initiative became the Drifting (later Data) Buoy Cooperation Panel (DBCP), that continues to organize drifting and moored buoy programmes via a number of action groups. The Panel also facilitates exchange of expertise and communal development of equipment and techniques. It appoints and funds a Technical Coordinator post tasked with ensuring the enhanced quality and quantity of drifting buoy data. In 1989, approximately 200 drifting buoys were providing data to the GTS, although there were known to be many more deployed. By 2000, over 750 buoys out of 1 300 known to be deployed were appearing via the GTS providing measurement of some or all of pressure, air temperature and sea temperature.
In parallel, a number of Members now regularly operate moored open-ocean data buoys at depths of up to 6 000 m.
The exchange and collation of marine climatological data were created with the objective of producing climatological atlases and summaries which could be consulted by those engaged in weather-sensitive marine activities. Given the limitations in the forecast period, climatology was also a powerful and necessary tool for ship routeing. By 1960, the main features of the WMO Marine Climatological Summary Scheme had been established and survives to the present day. Eight Members had each taken responsibility for an ocean area, and all other Members operating voluntary ships sent data from the areas to the appropriate Responsible Member.
In 1976, a project was proposed to transfer 20 million observations for the period 1860-1960 onto magnetic tape to create the Historical Sea Surface Temperature Dataset, which was then analysed to produce monthly means and standard deviations of sea and air temperatures and wind. The work was carried out by the Federal Republic of Germany, the Netherlands, USA and United Kingdom. With hindsight, the most valuable product was the carefully ordered dataset, rather than the statistical data.
During the next decade, it became apparent that customers, and particularly design engineers working for the offshore industry, required specialized analyses of the climatological data. Thus, it was more appropriate to concentrate resources on the creation of a good-quality climatological dataset than produce the summaries. It was decided to change the summaries scheme such that Responsible Members were only required to produce the summaries on demand. There was little or no demand.
Plans to produce a Marine Climatological Atlas were also dropped, but a Guide to the Applications of Marine Climatology was produced, assembling all the acquired experience and analysis techniques of those Members which had been working closely with various users from a range of marine industries.
Considerable effort was devoted to improving quality-control techniques, to eliminate the significant variations in performance exhibited by the systems used by the individual Responsible Members. Eventually, two Responsible Global Centres were set up in the United Kingdom and Germany, applying the same basic quality control to duplicate global datasets. Responsible Members continue to apply differing higher-level quality control schemes.
Ultimately, the large datasets created were used to support the WCRP and climate change studies, a somewhat more significant role than the humble origins of meeting the need for estimating the likelihood of cargo damage.
Early work on sea ice was inevitably focused on safety of navigation and concentrated on standardization of the nomenclature used by different Members for their warning services, as well as revised codes for reporting ice. During the early 1960s, CMM rationalized codes so that the same one was used by ship, shore station and, more importantly, by aircraft. The ice nomenclature was further enhanced by adding pictures, although progress was slow due to difficulty in obtaining suitable examples. There was also an attempt to standardize symbols on ice charts—surely a welcome initiative for the user!
By 1968, it was recognized that efforts had been almost completely targeted on the needs of the shipping industry, and a survey was initiated to identify other users. During the next decade, attention turned to the storage and retrieval of sea-ice data, and the need for a catalogue of such data, particularly in view of the climate change issue.
Over the next 10 years, a chart digitization code was developed, the emphasis being on use of the best, “end-of-season” version of each chart and arrangements for a centralized archive put in place. By the mid-1990s two global centres were operational in Boulder, Colorado, USA, and St. Petersburg, Russian Federation. The archived data are invaluable in support of the WCP and WCRP.
Guidance material was also produced both for mariners operating in sea-ice areas and those providing forecast and analysis services. Latterly, there has been close collaboration with the International Ice Charting Working Group to identify a practical mechanism to include sea-ice information in electronic navigation charts.
The most significant impact on this area of work was the availability of satellite data. Operational services tasked with providing ice-navigation services were once dependent on visual sightings from land and sea, then specialized airborne reconnaissance missions. They now have much more robust and reliable information on sea-ice cover thickness and ice edge provided by satellite-borne sensors.
Marine meteorology and oceanography
It is inevitable that the areas of endeavour of the marine meteorological and oceanographic communities will overlap.
Until the mid-1960s, the marine meteorological community was concerned with services to mariners, and cooperation was, therefore, largely concerned with waves and currents. Problems of measurement and deriving waves from wind data were addressed in a collaborative manner. Similarly, the OWS were used as platforms for wave-recorders, and latterly for subsurface profiling.
At CMM IV (1964), there was a discussion of the need to give meteorological personnel some oceanographic training, and an agenda item on the application of meteorology to oceanography. This was largely driven by work on ocean-atmosphere interaction. The discussion led to a formal request for closer cooperation with IOC. The latter adopted the concept of an Integrated Global Ocean Station System (IGOSS) and invited WMO to collaborate in 1968. IGOSS was conceived as the ocean version of WWW with components for observing, data processing and telecommunications, although the first manifestation of the new order was the use of marine meteorological platforms for ocean observing, and discussion regarding the need for spectral wave data.
Added impetus to collaboration was provided by the proposal from the Second World Climate Conference in 1990 to create a Global Ocean Observing System (GOOS) to provide analogous observations and systems for the oceans to those provided by WWW for the atmosphere. However, the proposal is even more ambitious in that it seeks to create the full range of activities and services for the ocean that modern meteorology provides for the atmosphere but with the added complication of ocean chemistry and biology.
The value of space-based remote-sensing technology to marine meteorologists and oceanographers was demonstrated by SEASAT in 1978 and subsequently by ERS 1 and ERS 2. Similarly, Topex-Poseidon, Quickscat and ADEOS 1 all made contributions. Initially, there was a reluctance to base operational products on these satellites because continuity was not assured. However, missions such as Metop, NPOESS, the JASON series, ICESat and ADEOS 2, point to a more assured future and meteorologists and oceanographers are collaborating to exploit the information, and also to convince the satellite operators of their requirement and the need for sustained provisions to meet them.
In the context of all the above factors, the President of CMM proposed to the 48th session of the WMO Executive Council in 1996 that the Commission for Marine Meteorology be replaced by a similar body jointly sponsored by WMO and IOC, with expanded terms of reference.
The Joint WMO/IOC Technical Commission for Oceanography and Marine Meteorology (JCOMM)
WMO and IOC recognized the complementary nature of programmes and expertise, as well as synergies and duplication in the activities of some of the management bodies. It was felt that benefits in terms of costs and coordination could be derived from a more coherent and consolidated approach to ocean monitoring. An additional benefit would be the ability of IOC to stimulate participation in ocean monitoring programmes by oceanographic institutions and agencies worldwide. In 1999, the WMO Congress and the IOC Assembly approved the creation of a Joint Technical Commission.
The first session of JCOMM was held in Akureyri, Iceland, in June 2001, and both the marine meteorological and oceanographic communities were well represented. A working group structure was created which took advantage of the strengths of the skilled people available from both disciplines, and a work plan was agreed. At the same time, the commitments of existing programmes were respected and preserved while exposing them to a cross fertilization of ideas.
The observation section of the agenda illustrates this:
This article has attempted to provide an outline of the development of marine meteorology and set the scene for progression to the fully integrated atmosphere, ocean observation, numerical modelling and services system which will eventually develop. Some 70 per cent of our planet consists of oceans, and we will always be affected by them, directly or indirectly. Those involved in marine activities, whether large-scale marine development or limited local aquaculture will require improved environmental services. The climate issue ensures that marine meteorology and oceanography is relevant to the entire human population.
Lieutenant Maury and his colleagues would undoubtedly be impressed if they could see how far their initial initiative has developed, but it is equally certain that they would point out how much more has yet to be done.
Forty Years of Progress and Achievement, a Historical Review of WMO. WMO-No 721, 1990.
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