COST CO-OPERATION IN METEOROLOGY
The atmosphere is a global common property in which weather systems
and pollutants transcend national boundaries. It therefore needs to be
monitored, understood and predicted, so that its impacts on society can be
managed, through co-ordinated and dedicated international co-operation.
Meteorological services are a fundamental component of the national
infrastructure in all countries, contributing to the security and safety of
citizens and serving socio-economic activities. They also advance the
understanding of our atmospheric environment and provide reliable
information suitable for various applications.
According to several
estimates, an effectively operating National Meteorological Service
(NMS) can achieve an overall benefit-cost ratio system of at least 10:1.
Despite the long tradition of European co-operation in operational
meteorology, there have been practical difficulties in co-ordinating
research initiatives and in improving collaboration between NMSs,
universities and industry.
The setting-up of the COST Technical
Committee for Meteorology in 1990 enabled a broader and more
integrated co-operation between NMSs and other European research
institutions in the field of atmospheric sciences. This led to a clear
increase in the number of Actions, a widening of topics, greater interdisciplinarity and integration of more countries and institutions, thereby
enhancing dissemination of results and building national capacities.
COST co-operation in meteorology has had a successful impact from the
very beginning as the first Action 70 (1971-73) led to the foundation of
the European Centre for Medium-range Weather Forecasts (ECMWF).
Nowadays, ECMWF has achieved a strong world-wide reputation as a
lead centre of excellence for weather forecasting and for cutting-edge
research in the field of numerical weather prediction (NWP) (Figure 1).
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FIGURE 1: The usability of ECMWF forecasts over the Northern Hemisphere
rises from 5.5 days in 1980 to 7.5 days in 2000.
Moreover, most COST Meteorological Actions have collaborated with
international organisations such as the ECMWF, the UN World
Meteorological Organization (WMO), the European Organisation for the
Exploitation of Meteorological Satellites (EUMETSAT), the European
Space Agency (ESA) and with EUMETNET (a European network of
NMSs). Such collaboration has given additional benefit to operational
practices through cost-effective transfer of innovative science.
RADARS: From Research Instruments to Operational Networks
The first COST Actions dealt with radar techniques and wind profilers,
reflecting the emerging interest in the new remote sensing technologies.
Weather radar data is essential for very short-term forecasting of weather
hazards such as heavy precipitation, for assessing flooding risks and
planning preventive measures.
Actions COST-72 (‘Measurement of
Precipitation by Radar’, 1979-84) and COST-73 (‘Weather Radar
Networking’, 1986-91) demonstrated the feasibility and cost-effectiveness
of a European weather radar network and the viability of data exchange.
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These two Actions provided the stimulus for a rapid increase in the
operational deployment of weather radars in Europe, passing from a
single system in 1974 to over 100 systems by 1991 (Figure 2). They were
subsequently organised into regional networks with the pre-normative
work done on data transfer protocol channelled into WMO guidelines.
Standardisation requirements created by these Actions have proved very
relevant for the industry.
FIGURE 2: Coverage of Europe by weather radar networks. Current work aims
at improving and harmonising data products for use in NWP models.
Subsequent technological developments (Doppler, polarimetric and other
multi-parameter facilities) stimulated a thorough review of the utility and
viability of these new systems in COST-75 (‘Advanced Weather Radar
Systems’, 1992-97). This led to recommendations for improving and
harmonising
processing
procedures
and
resulted
in
common
specifications for the next generation of weather radars of the European
network. COST-75 was the driving force that led NMSs to develop an
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operational administration of radar network data. Through these efforts,
the European radar community has reached a prominent position in the
field of radar meteorology. COST-75 also launched a series of biennial
open European conferences (ERAD) in order to maintain the momentum
and networking it had initiated.
Wind profiler radars have the capacity to estimate continuously and in all
weather conditions the three components of wind up to altitudes between
5 and 25 km, depending on the system used. This is a clear advantage
compared to balloon observations performed routinely only twice a day.
A network of European wind profilers would be a valuable tool for
improving detailed weather forecasts.
COST-74 (‘Utilisation of
VHF/UHF Radar Wind Profiler Networks for Improving Weather
Forecasting’, 1987-91) generated wind profiler radar specifications.
Moreover, the Action began the process of requesting from the UN
International Telecommunication Union allocation of frequencies needed
for the operational use of wind profilers.
The follow-up Action 76
(‘Development of VHF/UHF Wind Profilers and Vertical Sounders for
Use in Observing Systems’, 1994-2000) achieved the allocation of
frequencies, and established a semi-operational European network of
about 15 wind profilers with a hub for data collection, quality control and
data distribution.
The Action finally made recommendations for the
conversion of this network into a fully operational structure. COST-76
also proposed the new Action 720 (‘Integrated Ground-based RemoteSensing Stations for Atmospheric Profiling’, 2000-05) which considers
integration of various remote-sensing techniques at a single station by
exploiting the synergy of the combination both to improve quality control
and provide data on all the most important atmospheric parameters.
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It is noteworthy that industry participated actively in several of these
Actions both in research and in the assessment of techniques and
methodologies. This led to a better mutual understanding about demands
and technical possibilities.
Enhancing the Use of Satellite Data
Research and development on remote sensing from satellite platforms
were the core activities of Actions 712, 714 and 716. At the start of
COST-712 (‘Microwave Radiometry’, 1996-2000), the high potential of
microwave imagery for providing information on the Earth's environment
was far from being fully exploited and interactions between users and
researchers in Europe were weak. Development of microwave radiometry
is very delicate due to the wide range of parameters influencing the data.
Through COST-712, for the first time in Europe, experts on microwave
remote sensing technology, data and modelling joined experts on
atmospheric sciences to advance the application of microwave radiometry
from space.
COST-712 assessed some of the processes of radiative
transfer models, the basic tool for retrieving and interpreting remote
sensing data, and provided recommendations on necessary developments
and for applications of these models. One significant success was to help
identify the microwave radiometer as the most important single source of
data influencing the skill of numerical weather predictions.
Observing and forecasting the state of the sea is a major challenge with
various practical benefits for the safety of maritime activities and the
sustainable development of the coastal zone. Developments have been
hampered by the gap between the research community and the users:
mainly the port and maritime authorities and engineering companies.
Against this backdrop, COST-714 (‘Measurement and Use of Directional
Spectra of Ocean Waves’, 1996-2001) contributed to the improvement of
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methods for retrieving information on the state of the sea from satellite
data and developed alternative measuring systems.
It also defined
strategies for new field experiments and for new analysis of data. Various
users have so far collected sea-wave data in a completely unstructured
manner. COST-714 managed to put on the Internet a database giving the
various data formats and providing recommendations for data access.
The Action was also able to launch an interactive dialogue between the
two communities through dedicated conferences under the aegis of UNorganisations, UNESCO and WMO.
The Global Positioning System (GPS) is designed for global navigation.
However, if the position of the GPS receiver is already known, the signals
can be used to study the atmospheric influence (mostly by water vapour)
on the signals from GPS satellites. By bringing together space geodesists
and meteorologists, COST-716 (‘Exploitation of Ground-based GPS for
Climate and NWP Applications’, 1998-2003) aims to assess on an
international scale the operational potential of ground-based GPS
receivers for providing near real time observations for NWP and climate
research applications. The continuity and density of GPS data make them
very suitable for monitoring rapidly evolving, small-scale storms. COST716 will develop and demonstrate a prototype system together with a data
exploitation scheme for NWP. Another advantage of such a system is
that it can provide stable humidity observations over decades, allowing
detection of long-term climatic trends.
Operational Forecasting
A current trend in weather forecasting is towards tailor-made products for
various local users involved in transport by air, sea or land, farming,
energy distribution, tourism, sports and local outdoor events, watermanagement, construction, etc. These require a combination of high-
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resolution observational techniques, efficient standardised data analysis
and modelling. Many of these products are of high economic value and
fall under the label of nowcasting techniques, i.e. they provide a detailed
state of the atmosphere up to 6-12 hours ahead. Moreover, developments
for visualisation and dissemination to end-users by multi media devices
are increasingly needed.
Since such activities are predominantly
operational, developments have usually been ad-hoc and local without
much involvement of the R&D departments.
COST-78 (‘Development of Nowcasting Techniques’, 1994-99) was able
to fill this gap by reviewing various approaches, identifying strengths and
weaknesses and providing recommendations for further development at
European level. Results from COST-78 have led to better monitoring and
forecasting of extreme weather, such as thunderstorms and heavy rain,
that increasingly produce disasters in various European regions (Figure
3). COST-722 (‘Short-range Forecasting Methods of Fog, Visibility and
Low Clouds’, 2001-06), following on from Action 78, will develop new
methods, models and software for situations of poor visibility where local
topographical, climatic and environmental conditions are important.
It is a major theoretical, technical and operational challenge to use
effectively the huge amounts of radar data now available for improving
weather forecasts or for validating our understanding of atmospheric
processes. Thus, COST-717 (‘Use of Radar Observation in Hydrological
and NWP Models’, 1999-2004) is examining the requirements on
European radar data for their wider use in hydrological and weather
prediction models. The work will also lay the basis for using radar data
effectively in the validation of process description in these models.
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FIGURE 3: Radar estimate of 18-hour rainfall during the night of July 22-23
1998 localised in Eastern Bohemian mountains, and caused dramatic flash
floods with death of 6 people.
Modern outdoor lifestyles together with ozone depletion have raised
concerns about the increased exposure of humans to UV-B radiation with,
consequently, the increased risk of developing skin cancers.
One
essential service is thus to provide information on UV-B for public
awareness in a standardised manner so that tourists and the local
population can benefit equally from this information throughout Europe.
Forecasting UV-B strongly depends on forecasts of cloudiness and ozone
concentration.
COST-713 (‘UV-B Forecasting’, 1996-2001) assessed
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various models for UV-radiation computation and identified conditions
under which they are most accurate, and laid the foundation for an
improvement of UV forecasts.
In co-ordination with WMO and the
World Health Organization, it also provided guidelines for achieving a
harmonisation of the UV index. The Action also produced in several
languages a very illustrative booklet to further public education on
practical UV issues.
Agrometeorological and Climatological Services
Aiding weather-sensitive farming activities has been and remains an
important application of meteorological information.
The modern
requirement for tailor-made products necessitates the use of sophisticated
models, remote sensing methods and dedicated forecasts to provide
specific information on a fine spatial scale. The gap between advisers,
users and meteorological services has hampered the interpretation and
dissemination of the required information. These considerations were the
main reasons for the launching of three co-ordinated Actions (1994-98) in
the field of agrometeorology: COST-77 (‘Application of Remote Sensing
in Agrometeorology’), COST-79 (‘Integration of Data and Methods in
Agroclimatology’)
and
COST-711
(‘Operational
Applications
of
Meteorology to Agriculture, incl. Horticulture’). These Actions allowed
first assessments of the practices, needs and gaps in the services provided,
and tested new methods and models able to provide relevant information.
Based on this newly established networking, a follow-up Action COST718 (‘Meteorological Applications for Agriculture’, 1999-2004) is
addressing some urgent identified needs, such as the testing and
implementation of models for crop yield, irrigation and pests and
diseases. It will assess the availability of meteorological data for
agrometeorological models and will aim at improving the communication
channels between the two communities.
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The mapping and analysis capabilities of Geographic Information
Systems (GIS) are increasingly employed in climatology, meteorology
and other geosciences as well as by governance authorities especially for
environmental and land-use applications.
Typically, such studies are
multidisciplinary and require the combination of data from several
agencies and the use of spatialisation and other complex analysis
techniques to extract patterns in space and/or time. There is now a strong
need for improving ease of data exchange between disciplines as well as
expert assessments of the state of the art of GIS tools. COST-719 ('The
Use of GIS in Climatology and Meteorology', 2001-2005) will address
these concerns, develop applications and places particular emphasis on
standardising where possible. Results of the Action will be dissemination
of GIS expertise on a European scale.
Air Quality and Pollution Control
European legislation on air quality requires monitoring and assessment of
pollution level over national territory. This requires use of meteorological
dispersion models that should be comparable since pollutants cross
borders and pollution control values are the same throughout Europe.
With this perspective, COST-710 (‘Harmonization in the pre-Processing
of Meteorological Data for Dispersion Models’, 1994-97) performed
intercomparisons of sub-models that compute the sophisticated dispersion
parameters needed for the advanced models from simple routinely
measured meteorological quantities.
A subsequent Action, COST-715 (‘Urban Meteorology Applied to Air
Pollution Problems’, 1998-2003), is addressing the specific problems of
urban meteorology (70% of Europeans live in cities). Cities present
specific problems for the science of meteorology as they cause strong
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modifications to conditions prevailing in surrounding rural areas and
generate a microclimate of their own. Furthermore, most meteorological
measurements are made at rural or airport sites. Consequently, one has
generally no representative meteorological indicator of prevailing
conditions either over the city or within its complicated building canopy
(Figure 4).
COST-715 aims at defining practical criteria (e.g.,
interference-free reference height and location surroundings) for
performing such measurements in cities which, it is expected, will
become WMO guidelines. COST-715 also addresses the problem of the
wind field under stagnant wind conditions, associated with episodes of
strong pollution, when neither measurements nor operational NWP
models provide clear indication of the flow patterns. For the first time,
there is an opportunity to harmonise techniques for predicting such
episodes.
This Action has caused a reawakening interest in urban
meteorology, especially in NMSs, and an awareness of the limitations of
many commonly-made assumptions.
FIGURE. 4: A measuring station for urban pollution in Paris, with complex
flow conditions, traffic-induced turbulence and mobile sources of pollution.
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New Challenges Require Co-ordination through Co-operation
The flexibility and complementarity of the high-quality science
performed under COST have been demonstrated in the field of
meteorology and have contributed to many achievements that would not
have been possible otherwise. Research and development as well as
interdisciplinary co-operation in the field of meteorology, climate and
atmospheric sciences will certainly increase as the subject responds to
wider and deeper needs of society. For instance, many of the major
environmental issues such as climate change, ozone depletion and acid
rain have the atmosphere as the main stage.
Besides, many socio-
economic activities (e.g., transport, land-use, agriculture, energy
production, tourism) are becoming increasingly sensitive to weather and
climatic conditions and thus dependent on meteorological services and
information. Authorities need these services also to react promptly to
emergency conditions caused by natural hazards (e.g., floods, landslides,
avalanches, droughts, storms, icing), or industrial accidents (e.g.,
hazardous chemical releases, dispersion of radioactive compounds).
Thus, COST will continue to be a useful mechanism for boosting research
activity on key topics for society, ensuring standardisation and
disseminating expertise on a European scale.
Participation in COST
provides an essential support, impetus and training ground for R&D
activities in atmospheric sciences and their applications in Europe.