«Medium-Range Weather Prediction Austin Woods Medium-Range Weather Prediction The European Approach The story of the European Centre for Medium-Range ...»
Increased horizontal and vertical resolution will help to improve parametrization, for example by resolving more of the sub-grid orography and by better resolving the vertical structure of clouds. On the other hand, increased resolution may bring new problems of partially resolved mesoscale systems. Improvements in the parametrized physics will also increase the computational burden. Increased computing resources will allow more detailed modelling of the land surface scheme, new variables And the outlook is... 243 such as aerosols, improved physics codes of increased complexity, improved radiation, enhanced evaluation of model changes and better testing of new model versions.
Member States and Co-operating States are using ECMWF probabilistic Ensemble Prediction Systems (EPS) for medium- and extended-range forecasts in health management, agriculture, energy, hydrology, water management and more. The use of extended-range forecasts for severe weather prediction was rather limited initially, but following the success of the DEMETER project, research into application areas such as health and agriculture has been growing. It can be expected that the planned evolution of the forecasting system and the resolution increases to be implemented throughout the forecast range, together with research into the use of multimodel systems, will give a further boost to the development of new applications of these probabilistic forecasts.
Ensemble Prediction Systems are now recognised as essential to realise the economic value of numerical weather and climate forecasts. The key areas of development in EPS concern first the initial and model perturbation strategy, then determination of the resolution of the model versus the ensemble size. With the same computing resources, doubling the model resolution would mean decreasing the size of the ensemble by a factor of about ten.
However the balance between ensemble size and model resolution is not only scientifically complex, it may also depend on the users’ requirements and risk perception.
Intensive research will continue in many aspects of data assimilation. It will be increasingly important to produce reliable estimates of analysis uncertainty, as required for flow-dependent characterization of the short-range forecast error within the data assimilation itself, and for improved specification of the initial uncertainty in the EPS. This will involve near real time running of a data assimilation ensemble, necessarily at lower resolution than that of the main data assimilation cycle for the deterministic forecast.
Many different configurations for the future operational suite and substantial increases in analysis resolution can be envisaged. Continued improvement of the physics and better representation of background errors at small scales provide further prospects for benefit from higher-resolution analysis. Increased resolution of the forecast model allows for a more accurate comparison between observations as well as the use of high-resolution satellite observations.
It is certain that a vast amount of new data will become available in the next ten years or so. The current Envisat and EOS era provides a wealth of observational data from space. Beyond 2010, the operational Metop series will
244 Chapter 20measure upper troposphere greenhouse gas, for continuation of the Global Ozone Monitoring Experiment (GOME) capability for ozone. More greenhouse gas measurements for the upper troposphere will become available.
Exploitation of the new data including sea-ice, land, clouds and rain, and wind and temperature profiles through the depth of the atmosphere, will improve the observation of the hydrological cycle and monitoring of our global environment. Satellite data will be complemented by more data from “conventional” sources: more dropsondes from aircraft, more automated observations from commercial aircraft, and ground-based radar profilers measuring the atmosphere overhead to a height of 30 km. In the next five years, an increase in the volume of data by a factor of 10 or more can be anticipated, with further increases later when geostationary satellites provide high-resolution soundings.
The Centre will lead the EU-funded project on “Global and Regional Earthsystem (Atmosphere) Monitoring using Satellite and In-situ Data” (GEMS), an Integrated Project of the joint ESA-EU Global Monitoring for Environment and Security (GMES) initiative. The Centre will create a new European operational system to monitor atmospheric composition, dynamics and thermodynamics, and to produce medium-range and short-range air-chemistry forecasts, through improved exploitation of satellite data.
Sophisticated operational models and global and regional data assimilation systems exploiting satellite and in-situ data will be needed to provide initial data for the GEMS forecasts. The project will develop state-of-the-art estimates of the sources, sinks and inter-continental transports of many trace gases and aerosols. These estimates, based initially on the retrospective analyses, and later on operational analyses, will be designed to meet policy makers’ key information requirements relevant not only to the Kyoto and Montreal Protocols but to the UN Convention on Long-Range Trans-boundary Air Pollution as well.
These operational “status assessments”, which are accurate syntheses of all data, will allow sources, sinks and transports of atmospheric trace constituents to be documented, a requirement for the Kyoto Protocol, in which the developed nations agreed to limit their greenhouse gas emissions relative to the levels emitted in 1990.
GEMS will develop, and implement at ECMWF, a validated, comprehensive, and operational global data assimilation and forecast system for atmospheric composition and dynamics. The composition and dynamics of the atmosphere from global to regional scales, and covering the troposphere and stratosphere, will be monitored using all available remotely sensed and And the outlook is... 245 in-situ data. Operational deliverables will include current and forecast three-dimensional global distributions four times daily, with a horizontal resolution of 50 km, and with 60 levels between the surface and 65 km, of
key atmospheric trace constituents including:
• greenhouse gases, initially including carbon dioxide, and progressively adding methane, nitrous oxide, and the potent greenhouse gas sulphur hexafluoride, together with radon to check advection accuracy,
• reactive gases, initially including ozone, nitrogen dioxide, sulphur dioxide, carbon monoxide and formaldehyde, and gradually widening to include more, and
• aerosols with initially 10 parameters represented, extending later to perhaps 30 parameters.
The global assimilation and forecast system will provide initial and boundary conditions for operational regional air-quality and “chemical weather forecast” systems across Europe. This will allow the impact of global climate changes on regional air quality to be assessed. It will also provide improved operational real-time air-quality forecasts. GEMS will mobilise European expertise to create such operational services and capabilities. It is hoped that GEMS systems will become operational by early 2009.
Access to substantial High-Performance Computing (HPC) resources has been a major factor contributing to the success of the Centre. It has provided a very good user service with a high level of use of the resources.
ECMWF’s research community, both in-house and in the Member States, has been able to rely on a good turnaround for numerical experiments.
Visiting scientists have commented on the high productivity achieved. The development of tools such as “PrepIFS”, software that made submission of analysis, forecast, seasonal prediction and EPS experiments easy, was an important contributor to this. Another welcome effect is that of enabling changes to the forecasting system to be carefully tested before being put into production.
Data handling and archiving services will continue to be key components of the Centre’s research and operational framework. The Centre’s archive will evolve to cater for the ever-increasing volume of observations.
Throughout the life of the archive, user access patterns have changed as technology advanced. The archive will support very large research experiments, such as re-analyses, or very long integrations extending over decades and centuries. To make full use of the wealth of information, data mining techniques will be investigated.
246 Chapter 20The Centre’s popular Seminars, Training Courses and Workshops in meteorology and computing will continue to serve the meteorological community of the Member States and elsewhere.
GARP was launched in 1967. The GARP objectives were to study the physical processes in the atmosphere that are essential for an understanding of:
• The transient behaviour of the atmosphere as manifested in large-scale fluctuations which control changes in weather, to increase the accuracy of forecasting over periods from one day to several weeks; and
• The factors that determine the statistical properties of general circulation in the atmosphere, which would lead to better understanding of the physical basis of climate.
In 1973, there was not a single global NWP centre. Today, almost 40 years after the launch of GARP, there are several. In 1975, there was possibly one published paper on numerical prediction of a tropical cyclone. Today there is an extensive literature on the subject. Television viewers expect to be kept informed on the most recent computer predictions of hurricanes approaching land. The Centre’s plans are for a challenging future that surely will see advances comparable to those achieved in its first 30 years.
The Centre’s team of world-class technicians and scientists produces the best medium-range and seasonal forecasts of the global atmosphere and oceans. The delegations at Council, representing their States, are facing the challenge of ensuring that the Centre’s environment continues to attract these talented people.
In the final analysis, the users of the Centre’s forecasts are the people, not only in Europe but also throughout the world, who rely on the best possible weather information to plan and carry out their daily activities. They have a right to expect value for the money they spend, through their taxes, on meteorology. The Centre has its duty to continue to do its best to provide the most accurate information.
The meteorological world will watch with great interest as the Centre, its Council, Director and staff, tackle the scientific, technical, financial and administrative challenges facing it.
The Council appoints the Director. He is the Chief Executive Officer of
the Centre. Consequently he:
• Represents the Centre in dealings with third parties.
• Is responsible to the Council for the execution of the tasks assigned to the Centre.
• Attends all meetings of the Council.
The Director ensures the proper functioning of the Centre. In carrying
out this responsibility he:
• Appoints staff, except the Heads of the three Departments, who are appointed by Council on the Director’s recommendation.
• Submits each year the draft programme of the activities of the Centre for the following four years, together with the opinions and recommendations of the Committees on the programme.
• Prepares and implements the budget of the Centre.
• Keeps a record of revenue and expenditure, submits annually for the approval of the Council the accounts relating to the budget, and the balance sheet of assets and liabilities.
• Reports on the activities of the Centre.
• Concludes co-operation agreements.
Prof Dr Aksel Wiin-Nielsen ECMWF Director 1 January 1974 to 31 December 1979 See Chapter 1 ‘The First Director’ Born: 17 December 1924 Nationality: Danish Education: Fil. dr. in Meteorology from University of Stockholm, 1960 M. Sc. in Mathematics from University of Copenhagen, 1950 Fil. lic. in Meteorology from University of Stockholm, 1957
1995: Professor Emeritus, University of Copenhagen 1987-1994: Professor of Physics, University of Copenhagen 1984-1987: Director, Danish Meteorological Institute 1980-1984: Secretary-General, World Meteorological Organization (WMO) 1974-1979: Director, ECMWF 1963-1974: Professor and Chairman, University of Michigan, USA 1961-1963: Scientist, Center for Atmospheric Research (NCAR), USA 1959-1961: Staff Member, Joint Numerical Weather Prediction (JNWP), Suitland, USA 1955-1958: Staff Member, International Meteorological Institute (IMI), Stockholm 1952-1955: Staff Member, Danish Meteorological Institute The Directors 249 Jean Labrousse ECMWF Director 1 January 1980 to 31 December 1981 Aksel Wiin-Nielsen left to take on the post of Secretary-General of WMO in 1979. At its session in June 1979, the Council set up a Selection Committee to consider the appointment of a Director, and by postal ballot, Jean Labrousse was appointed the Director of the Centre. He had been Head of the Operations Department since June 1974, and served as Director for just two years.
M. Roger Mittner, Director of Météorologie Nationale, retired on 31 December 1981. Labrousse was appointed as Director of Météorologie Nationale from 1 January 1982 by the Conseil des Ministres.
Prof Dr Lennart Bengtsson ECMWF Director 1 January 1982 to 31 December 1990 Dr Lennart Bengtsson had been Head of Research at the Centre since July 1974. In November 1981, Council appointed him as Director from 1 January
1982. His appointment was renewed in 1985.
In May 1990, Bengtsson notified Council that he had been offered a post as Director within the Max-Planck-Gesellschaft in Germany and that it was his intention to accept the offer.