THe Observing-system Research and predictability experiment
THORpex
1.General description
A Global Atmospheric Research Programme THORPEX is a ten-year international research programme, under the auspices of the Commission of the Atmospheric Science, and its World Weather Research Programme (WWRP). The purpose of THORPEX is to accelerate improvements in short-range (up to 3 days), medium-range (3 to 7 days) and extended-range (week-two) weather predictions and the social value of advanced forecast products. THORPEX would examine global-to-regional influences on the predictability of high-impact weather and establish the potential to produce significant statistically-verifiable improvements in forecasts of those time scales.
2. Scientific background
The success of numerical weather prediction represents one of the most significant scientific, technological and societal achievements of the 20th century. Despite the notable increase in forecast skill over the past quarter century (Fig.1), there is a necessity for further improvements, particularly, in high-impact weather forecasts and in the use of weather information. High-impact weather forecasts are defined by their effect on society and the economy. They are typically associated with forecasting cyclones of extratropical and tropical origin that contain significant embedded mesoscale weather, such as localized flooding by convective and orographic precipitation; blizzard snows; destructive surface winds; dust-storms. T hey also encompass meteorological conditions affecting air quality, periods of anomalous high/low temperature and drought, and non-extreme weather with high-societal impact. Improving the skill of high-impact weather forecasts is one of the great scientific and societal challenges of the 21st century. THORPEX is a response to this challenge.
Fig. 1: Evolution of forecast skill for the northern and southern hemispheres: 1980-2001. Anomaly correlation coefficients of 3, 5, and 7-day ECMWF 500-mb height forecasts for the extratropical northern and southern hemispheres, plotted in the form of running means for the period of January 1980-august 2001. Shading shows differences in scores between hemispheres at the forecast ranges indicated (from Hollingsworth, et al. 2002).
Emerging developments in atmospheric science and technology provide the opportunity for dramatic improvements in weather forecasts and in their use and value to society. These developments include: i) advances in the knowledge of the theoretical and practical limits of atmospheric predictability, including the influence of inter-annual and intra-seasonal climate variability on forecast skill; ii) expanding observations of the Earth System with satellite, airborne, marine and land-based observing technologies; iii) weather forecast systems capable of assimilating observations from the above diverse technologies; iv) advanced forecast procedures aided by improvements in numerical techniques, parameterised and explicit representations of physical processes, ensemble forecast techniques, and exponential increases in the speed and memory of supercomputers; v) innovative approaches to the design and implementation of forecast systems that optimise the societal and economic utilisation of weather information. In the same way that the atmosphere encompasses the globe, the expertise to exploit and further these advances resides across many nations, international organisations, and different scientific disciplines.
Fig. 2: Satellite Stations
THORPEX establishes a contemporary organisational framework to address global weather research and forecast problems whose solutions require international and academic-operational collaboration. This will include engagement with other international programmes within the World Meteorological Organization (WMO), the International Council of Scientific Unions (ICSU) and the Intergovernmental Oceanographic Commission (IOC). In this regard, THORPEX aspires to be a successor of the Global Atmospheric Research Programme (GARP); building on the accomplishments of the First GARP Global Experiment (FGGE).
The core research objectives of THORPEX are to:
- Contribute to the design and demonstration of interactive forecast systems that allow
information to flow interactively between forecast users, numerical forecast models,
data-assimilation systems and observations. Interactive forecast systems include the
new concept of targeted observations, referred to as targeting. Targeting incorporates
dynamical information from the numerical forecast model itself to identify when, where,
and what types of observations would provide the greatest improvement to specific weather
forecasts.
- Advance the knowledge of global-to-regional influences on the initiation, evolution, and
predictability of high-impact weather. This will include research into: i) the degree to
which predictive skill is limited by observations, data assimilation, model uncertainty,
or ensemble prediction system design at various forecast lead-times; ii) the excitation of
Rossby wave-trains by extratropical cyclogenesis, large-scale topography, continent/ocean
interfaces, and organised tropical and extratropical convective flare-ups, and the consequent
initiation of high-impact weather; iii) the dependence of predictive skill on inter-annual
and intra-seasonal climate variability, e.g., El Nino Southern Oscillation (ENSO);
Pacific North-Atlantic oscillation (PNA); North-Atlantic Oscillation (NAO); monsoon
circulations.
- Collaborate with numerical forecast centres in the development of advanced data-assimilation
and forecast model systems. Research will include: i) improving the assimilation of existing and
experimental observations, including observations of physical processes and atmospheric composition;
ii) developing adaptive data-assimilation and targeted-observing strategies; iii) incorporating
model uncertainty into data-assimilation systems and in the design of ensembles.
- Develop and apply new methods to enhance the utility of improved weather forecasts through:
i) the use of new user-specific probabilistic forecast products; ii) the introduction of
interactive procedures that make the forecast system more responsive to user needs; iii)
the design of and training in the use of user-specific forecast products. This research will
identify and assess the societal/economic costs and benefits of THORPEX recommendations for
implementing interactive forecast systems and improvements in the global observing system.
- Perform THORPEX Observing-System Tests (TOSTs) and THORPEX Regional field Campaigns (TReCs).
TOSTs will: i) test and evaluate experimental remote-sensing and in-situ observing systems,
and when feasible, demonstrate their impact on weather forecasts; ii) explore innovative uses
of operational observing systems. TReCs are quasi-operational forecast demonstrations contributing
to the design, testing and evaluation of all components of interactive forecast systems. They will
be organised and coordinated by regional consortia of nations under their respective THORPEX
Regional Committees (European, Asian, North-American, and Southern Hemispheric) TReCs will
address regional high-impact weather events, e.g., arctic storms and cold-air outbreaks;
cool-season extratropical cyclones over Europe, Asia, and North America; warm-season
tropical-to-extratropical cyclone transformations.
Fig. 3: A spagetti plot for an example prediction system ( from the Korean contribution to Asia-Thorpex, 2004)
- Demonstrate the full potential of THORPEX research results for improving operational forecasts
of high-impact weather on time-scales out to two weeks. This demonstration includes the THORPEX
Global Prediction Campaign (TGPC). The TGPC will: i) deploy and/or activate the full suite of
experimental and operational observing systems over the globe for a season to one year; ii)
establish the utility of interactive forecast systems to improve the utility of weather forecasts
and user products; iii) provide guidance, through the WMO/World Weather Watch (WWW) to agencies
responsible for optimising the design and implementation of the fixed and adaptive components of
the existing regional and global observing systems; iv) coordinate the transfer and application of
THORPEX research and operational results to developing countries.
THORPEX is unique, in that:
- It establishes an organisational framework that addresses today’s global weather research and
forecast problems whose solutions require international and academic-operational collaboration.
Its research domain spans global-to-regional influences on the prediction of high-impact weather.
It considers those mesoscale weather systems that form in response to the larger-scales and not
those arising from purely local influences.
- It has at its heart, the contemporary paradigm in which weather forecasting is addressed as
an interactive system with information flowing between forecast users, forecast models, data
assimilation and global and regional observing systems.
- It will conduct regional and global campaigns as demonstrations and assessments of new
observing technologies and interactive forecast systems. Thereby, THORPEX will provide guidance to
the World Weather Watch and forecast centres on improvements to forecast systems, and to the
relevant bodies, such as the WMO Commission for Basic Services Open Programme Areas Group,
concerning optimisation of global and regional observing-systems.
- It addresses the influence of intra-seasonal time scales on week-two high-impact forecasts,
and therefore aspires to bridge the “middle ground” between medium-range weather forecasting and
climate prediction. This provides a link with other programmes addressing the improvement of global
climate-change prediction systems.
Nations and consortia of nations have established Regional Committees (North American, European and Asian) that define regional priorities for participation in THORPEX within the framework of the THORPEX International Science and Research-Implementation Plans.
Science Program
Predictability and Dynamical Processes;
Observing Systems;
Data Assimilation and Observing Strategies;
Societal and Economic Applications.
These Sub-programmes have the responsibility to: i) coordinate the research activities envisaged in the THORPEX International Science and Research Implementation Plans; ii) collaborate with other international programmes when relevant expertise is required and mutual benefit is derived.
3. The partners and membership
The membership of the THORpex International Scientific Steering Committee (ISSC) contains representatives from Canada, China, Japan, Russia, United Kingdom, United States, France, Norway, Iceland, Finland, and Sweden. The membership will continue to expand as additional countries become involved in the Program. The ISSC includes the Co-Chairs (*) of the THORpex Science Plan Sub-program development teams .The THORPEX International Science Comitee (ISSC) establishes the core research objectives with recommendations from the THORPEX International Core Steering Comitee (ICSC) whose members are nominated by Permanent representatives countries with WMO .
The membership of the Thorpex ICSC (December, 2003):
Members:
| Dr Michel BÎland | Chairman,Director General of Atmospheric and Climate
Science of the Meteorological Service of Canada 2121 Transcanadienne Dorval, Quebec H9P, 1J3 Canada Tel: +1 514 421 4771 Fax: +1 514 421 2106 E-mail: michel.beland@ec.gc.ca |
| Dr Alexander Frolov | Deputy Head, Russian Federal Service for
Hydrometerology and Environmental Monitoring (Roshydromet) 12, Novovagan’kovsky per., 123995 Moscow Russia Tel: +7 095 252 0313 Fax: +7 095 255 5226 E-mail: afrolov@mecom.ru |
| Dr Hyosang Chung | Director-General, Meteorological Research Institute,
Korea Meteorological Administration 460-18, Sindaebang-dong, Dongjak-gu Seoul 156-720 Republic of Korea Tel: +82 2 849 0665 Fax: +82 2 849 0668 E-mail: hschung0@metri.re.kr |
| Dr Jean Pailleux | Vice Director, Centre National de Recherches
MÎtÎorologiques (CNRM) de MÎtÎo France 42 Avenue Coriolis 31057 Toulouse Cedex France Tel: +33 5 6107 8452 Fax: +33 5 6107 8453 E-mail: jean.pailleux@meteo.fr |
| Dr Jim Caughey | EUCOS Programme Manager Met Office London Road Bracknell Berkshire RG12 2SZ from 18/11: FitzRoy Road Exeter Devon EX1 3PB United Kingdom Tel: +44 (0) 1344 854612 Fax: +44 (0) 1344 854948 E-mail: jim.caughey@metoffice.com |
| Keiichi Kashiwagi Acting |
Counsellor, Administration Department Japan Meteorological Agency 1-3-4 Otemachi, Chiyoda-ku, Tokyo 100-8122, Japan Tel: Fax: +81 3 3211 2032 E-mail: kashiwagi@met.kishou.go.jp |
| Dr Louis Uccellini | Director, National Centers for Environmental
Prediction (NCEP) World Weather Building, Room 101 5200 Auth Road Camp Springs, MD 20746-4304 USA Tel: +1 301 763 8016 ext. 7000 Fax: +1 301 753 8434 E-mail: Louis.Uccellini@noaa.gov |
| Prof. Ulrich Schumann | Institut fur Physik der Atmosphare Deutscher Wetterdienst (DWD) D-82230 Wessling Germany Tel: +49 8153 28 2520 Fax: +49 8153 28 1841 E-mail: ulrich.schumann@dlr.de |
ICSC EX-OFFICIO Members
| Dr Melvyn Shapiro | Co-Chair ISSC for THORPEX NOAA Office of Weather and Air Quality c/o NCAR/MMM P.O. Box 3000 Boulder, CO 80307-3000 U.S.A. Tel: +1 303-497-8965 Fax: +1 303 497-8181 E-mail: mshapiro@ucar.edu |
| Dr Richard Carbone | Chairman CAS SSC/WWRP National Center for Atmospheric Research P.O. Box 3000 BOULDER, CO 80307 USA Tel: +1-303 497 8926 Fax: +1-303 497 8181 E-mail: carbone@ucar.edu |
| Dr Elena Manaenkova | Director Atmospheric Research and Environment
Programme Department World Meteorological Organization 7 bis, avenue de la Paix Case postale No 2300 CH-1211 Geneva 2 Switzerland Tel: +41 22 7308212 Fax: +41 22 7308049 Email: EManaenkova@wmo.int |
| Mrs AngÏle Simard | WMO Commission for Basic Systems Chair Open Programme Area Group on Data Processing and Forecasting Systems Canadian Meteorological Center 2121 North Service Road, Trans-Canada Highway, Dorval, Quebec, H9P, 1J3 Canada Tel: +41 22 7308212 Fax: +41 22 7308049 Email: angele.simard@ec.gc.ca |
| Dr David Parsons | Co-Chair North American Regional Committee Senior Scientist, National Center for Atmospheric Research Mesoscale and Microscale Meteorology Division Boulder, Colorado 80307 USA Tel: Fax: Email: parsons@atd.ucar.edu |
| Dr Pierre Gauthier | Co-Chair North American Regional Committee Research Scientist, Data Assimilation and Satellite Meteorology Division Meteorological Service of Canada Dorval, QuÎbec Canada Tel: Fax: Email: Pierre.Gauthier@ec.gc.ca |
| Dr David Richardson | Co-Chair European Regional Committee Met Office United Kingdom Tel: Fax: Email: david.s.Richardson@metoffice.com |
| Dr Chen Dehui | Co-Chair Asian Regional Committee Deputy Director, Research Center for Numerical Meteorological Prediction, China Meteorological Administration 46 Zhongguancun Nandajie, Beijing 100081 China Tel: Fax: Email: chendh@cma.gov.cn |
| Dr Pai-Yei Whung | Interim Director THORPEX International Programme Office Department of Commerce Associate Director Office of Weather and Air Quality NOAA/OAR R/OAR, SSMC#3, rm#11108 1315 East-West Highway Silver Spring, MD 20910 USA Tel: +1 301 713 0460 ext. 204 Fax: +1 301 713 3515 Email: Pai-Yei.Whung@noaa.gov |
