by André Kamga Foamouhoue1, Jose María Baldasano2, Emilio Cuevas Agulló3, Aïda Diongue-Niang4, Carlos Pérez García-Pando2, Eugene Poolman5 and Madeleine Thompson6
Dramatic and sustained improvements have occurred in our prediction capabilities for air quality, climate and weather (e.g. Hollingsworth et al., 2005; Intergovernmental Panel on Climate Change, 2008; Uppala et al., 2005). Nevertheless, the demands for more accurate predictions have increased due to the exponential growth of population, climate change and the increasing susceptibility of society to natural disasters and poor air quality by concentrating populations in urban centres, coastal regions and river valleys.
Mitigating strategies are a particular challenge for Africa with many developing nations of which more than 30 are among the 49 Least Developed Countries (LDCs) of the world. Such nations have limited ability to mitigate natural disasters which threaten public safety but also cause shock waves that ripple through fragile economies. For example, tropical-cyclone-related floods reduced Mozambique’s annual growth rate from 8 per cent to 2.1 per cent in 2000. Droughts in East Africa reduced the hydro-electric potential of Kenya, leading to an emergency loan of more than US$ 50 million. Poor air quality from biomass-burning, sand and dust and air pollution is also a growing concern.
As a result, changes have occurred in the orientation of African National Meteorological and Hydrological Services (NMHSs) from one of primarily taking meteorological observations to one of contributing to sustainable development by assisting public safety and sensitive economic activities (Afiesimama, 2007). The foundation for this shift in orientation is the ingenuity and initiative of the NMHSs, often in partnership with WMO Members outside Africa, that have resulted in both improved use of modelling products and limited area models being run locally by several NMHSs in Africa. This paradigm shift is also supported by broad international collaboration that has developed under WMO.
This article describes three project that range in scope from bringing immediate benefits to Africa by improving access to, and the utility of, prediction products of the developed world to a 10-year research and development plan to enhance predictive and mitigation capacities within Africa.
Severe Weather Forecasting Demonstration Project
The current capabilities of leading numerical weather prediction (NWP) centres include high-resolution deterministic models that provide the best estimate of future weather and ensemble prediction systems (EPS) that attempt to capture the range of possible outcomes and extend the useful range of forecasts. These advances have meant that the lead-time of severe weather warnings has increased far beyond the traditional two days with routine useful forecasts issued up to five days in advance with outlooks several days beyond. Unfortunately, few NMHSs of developing nations and LDCs have adequate access and make extensive use of the high-resolution products; even fewer make use of EPS to reach these extended lead-times.
To ensure that LDCs and developing nations also benefit from the revolutionary advancements in predictive skill, the WMO Commission for Basic Systems (CBS) initiated the Severe Weather Forecasting Demonstration Project (SWFDP). Its aims include the improvement in accuracy and lead-time of forecasts of severe weather events, improving the lead-time of alerts for these events and improving the interaction of NMHSs with emergency management authorities before and during events.
The project utilizes the network of Global Data Processing and Forecasting System (GDPFS) centres to provide state-of-the-art operational products through a cascading forecasting process (e.g. global production centres to NMHSs through regional centres). The first regional subproject was conducted in south-eastern Africa from November 2006 to November 2007 with the European Centre for Medium Range Weather Forecasts (ECMWF), the US National Centres for Environmental Prediction (NCEP) and the United Kingdom Met Office acting as Global Product Centres.
The Regional Specialized Meteorological Centre (RSMC) of Pretoria (designated to the South African Weather Service), was responsible for the distribution of the NWP and EPS products through a dedicated Website to five participating NMHSs (Botswana, Madagascar, Mozambique, United Republic of Tanzania and Zimbabwe), which maintained control over the final decision on issuing warnings to their emergency management authorities. RSMC Pretoria also provided daily guidance products of potential heavy rain or strong wind for the next five days, based on an analysis of all available NWP and EPS products. RSMC La Reunion, responsible for tropical cyclone forecasts in the South Indian Ocean, maintained normal operations and supported the project with valuable information on tropical cyclones. The project included training for the five participating NMHSs to enhance the use of guidance and model products on the RSMC Pretoria Website. The project is being expanded to all 16 countries of Southern Africa and should prove to be a useful model for developing nations and LDCs elsewhere. Further details on this successful project can be found in the recent article by Poolman et al. (2008) in the December edition of MeteoWorld.
Sand-and duststorms in Africa: opportunities to better monitor and predict the risk-reduction process
When winds are strong, large amounts of sand and dust can be lifted from bare, dry soils and transported into the atmosphere downwind, affecting regions hundreds to thousands of kilometres away. Approximately 1 000-3 000 Tg of dust is exported from source regions each year. The Sahara Desert is the largest source of mineral dust aerosol and contributes 50-70 per cent of the dust emitted worldwide. For countries in and downwind of the Saharan Desert, airborne sand and dust present serious risks to the environment, property and human health. Saharan dust also plays an important role in climate and weather due to their direct (radiative forcing) and indirect (clouds, precipitation) impacts on the atmosphere.
In the early 1990s, it was understood that, if dust concentrations were included as predictive variables in NWP models, successful predictions of the atmospheric dust process (emission, turbulent mixing and deposition) could be performed. A first experimental dust forecast was performed in 1993 for the North African and Mediterranean region. However, modelling with an accurate dust component could not be accomplished without corresponding observations. In the beginning of the 1990s, only synoptic visibility observations and coarse Meteosat images indicating dust presence over the sea were available to validate dust forecasts. Several subsequent projects and initiatives have been launched to improve our knowledge of the dust process and its impacts in Africa, including aspects of the African Monsoon Multidisciplinary Analysis–Special Observation, the Saharan Mineral Dust Experiment and the Bodélé Dust Experiment 2005 (the Bodélé Desert is believed to be the largest single source area in the Sahara).
Dust modelling and related measurements have drastically improved over the last 15 years. Today, there are a number of advanced atmospheric dust models producing daily research forecasts; there are also several other models used for scientific research, including very Latest issue models. A number of most recent satellite products from NASA (e.g. MODIS, CALIPSO) and ESA (Meteosat Second Generation) are capable of detecting dust over the Saharan region in Latest issue modes and to observe its vertical structure. There are also other complementary observational dust activities such as lidar networks (WMO GALION), sunphotometry (GAW/AERONET-PHOTONS/SKYNET) and particulate matter networks. Six dust forecast models are routinely run over the African and Mediterranean region, providing publicly available products.
Fifteen countries in the region have shown interest in improving their capabilities to forecast and understand the dust process. As a response to the interest, and with the support of Fourteenth World Meteorological Congress, the WMO secretariat launched the Sand and Dust Storm Warning, Advisory and Assessment System (SDS-WAS) in 2007 as a joint project of the World Weather Research Programme (WWRP) and the Global Atmospheric Watch (GAW) under the WMO Commission for Atmospheric Sciences. The SDS-WAS mission is to enhance the ability of countries to deliver timely and quality sand-and duststorm forecasts, observations, information and knowledge to users through an international partnership of research and operational communities. SDS products will be created and delivered to users via the Web with the aim of having the same output from the various participating models displayed in identical formats over a single, uniform agreed upon domain. The project will also include a near-real time verification system. Capacity-building will be a major component of the regional Centre in Africa in order to improve both observation technology and the capacities of countries to utilize SDS observations and forecast products to meet the needs of their societies. SDS-WAS and MERIT are also GEO activities to assist in capacity-building.
|Figure 1 — The international network of SDS-WAS comprised of federated nodes, assisted by regional centres|
An SDS-WAS regional centre for Northern Africa, Middle East and Europe is being hosted by Spain. This regional node has generously provided technical support staff, data storage and Web capabilities with the possibility of using local high-performance computational resources. To meet user needs, the Regional Centre in Spain already provides daily dust prediction products for northern Africa. The steering group for this region met in Tunis-Carthage in November 2008 to implement a near-real-time system in 2010 and begin the process of requesting formal participation of operational and research modeling centres. National users and international organizations will be consulted in the development of useful products and tools. This regional effort also includes a 40-year re-analysis product containing a historical database of dust forecasts to develop climatological tools and to support applications such as for the health community (see box above). A second regional centre for Asia is being hosted by the China Meteorological Administration. The coordination between both regional centres is guaranteed through the WMO SDS-WAS Steering Committee.
|Figure 2 — Proposed domain for the Northern Africa, Europe and Middle Eastern node of the SDS-WAS project|
Reducing impacts of natural disasters and contributing to food security in Africa
The challenges in Africa for air quality, weather and climate are numerous (WMO, 2008). Africa has a population of several hundred million, who place significant pressure on resources, food supply and demand, especially in desert margins. It is also among the most vulnerable of the world to hydrometeorological disasters. The observing and modelling systems of the region have relatively high deficiencies. In addition, weaknesses in communication infrastructure in most African countries have created a barrier to disseminating forecasts products. These challenges imply that significant benefit would occur from a long-range strategy to improve not only predictive skill of the models but also the infrastructure, scientific capabilities and technical expertise of Africa. These improvements would allow Africans to play a far greater role in developing and implementing improvements in forecasting and in responding to, and mitigating, the detrimental effects of weather, air quality and climate change.
|Figure 3 — Water availability in Africa for 1990 and 2025|
The THORPEX (The Observing System Research and Predictability Experiment) programme of the WMO WWRP has developed an ambitious 10-year plan to assist in achieving these improvements. THORPEX was established as a 10-year international research and development programme in 2003 by Fourteenth World Meteorological Congress to focus on research that would accelerate improvements in the accuracy of one-day to two-week forecasts of high-impact weather and to realize the related societal, economic and environmental benefits of improved prediction (Shapiro and Thorpe, 2004; THORPEX/International Core Steering Committee, 2005). The WWRP-THORPEX African Science plan was developed in 2006 and 2007, following planning meetings in Ouagadougou, Burkina Faso, and Karlsruhe, Germany, in February and November 2007, respectively. An implementation plan was developed, using the foundation provided by the science plan with a third WWRP/THORPEX Africa planning meeting in Pretoria, South Africa to agree on a final vision. These three meetings are the cornerstones of the African THORPEX Science and Implementation Plans and the establishment of a Regional Committee.
The THORPEX Africa effort will contribute to development objectives agreed at UN conferences and summits (e.g. the World Summit on Sustainable Development in Johannesburg, South Africa in 2002; the WMO Conference on secure and sustainable living; social and economic benefits of weather, climate and water services in Madrid, 2007). The programme was developed by African researchers for Africa. The current version of these plans will be vetted by NMHSs and other potential participants early in 2009, leading to a final version of the plan in the summer of 2009. The THORPEX-Africa plan puts special emphasis on activities that contribute to societal benefits and the utilization of advances in EPS deterministic models. The plan is user-driven, focusing on the following key application areas:
Water management: the vulnerability, stress and scarcity of water are impediments to secure and sustainable development for many African countries. THORPEX will contribute to integrated water resource management with better heavy rainfall and flooding forecasts and warnings.
|Figure 4 — Malnutrition and food shortages in Africa|
Food security: The majority of African countries have experienced severe malnutrition, food shortage or famine over the past decades. The USAID/Famine Early Warning System (FEWS) already operating in Africa will work with THORPEX Africa to test advanced forecasting systems to improve early warnings with integrated forecasts from days to a season, while the African Economic Research Consortium will assess the damage of past high impact weather events on food security and develop tools to estimate the incremental benefits.
Energy: Weather hazards contribute to power shortages over Africa by damaging production and distribution infrastructure, reducing supply and increasing demand. Power shortages have increased in Africa over the past decade and THORPEX Africa envisages collaboration with major power corporations to develop and demonstrate better estimates of supply, demand and early warning information.
Transportation: An important source of income of most African NMHSs is services to aviation. WWRP/THORPEX will support further improvements to these meteorological services to sustain and strengthen the thrust and visibility of NMHSs and thus facilitate the development and implementation of an AMDAR-Africa project.
Health: Malaria, meningitis, Rift Valley fever and cholera are among weather-/climate-driven diseases that hit African countries. The existing partnerships for MERIT (see box above) between WMO and WHO is a framework to engage the health community in studies to better understand weather-and climate-health relationships and improve on epidemic preparedness and response plans.
|... changes have occurred in the orientation of African National Meteorological and Hydrological Services from one of primarily taking meteorological observations to one of contributing to sustainable development by assisting public safety and sensitive economic activities.|
The interested reader is referred to the complete Science and Implementation Plans on the Web and asked to provide comments. A few highlights of the WWRP/THORPEX Implementation Plan for Africa are:
To enhance the use of available observing technologies, including satellite-based remote-sensing, assess the performance of operational and special observation networks on predictive skill, and provide recommendations to the WMO Commission for Basic Systems for an optimal low-cost observing network from the prospective of of high impact weather;
A weather information system for Africa will be developed in collaboration with the United Nations Educational, Scientific and Cultural Organization/International Centre for Theoretical Physics with the identification of high-impact weather events, impact data, analysis methods and tools. These will support joint initiatives between socio-economic, environmental and forecasting scientists to develop end-to-end products and services. A workshop to define the content of this system will take place in 2009. A subsequent effort will define predictive skill to help isolate weaknesses in the chain of events from model prediction to the utilization of weather information;
THORPEX Africa will contribute to a seamless integrated forecasting system in Africa that uses deterministic and EPS products from days to seasons and decades. This activity will start by identifying existing products at daily, weekly, biweekly and monthly timescales at global centres and assess their availability, quality, utility and potential added value;
Forecast verification, damage, losses and cost/benefit assessments will be made from a user perspective and cost/benefit assessment schemes will be developed in the framework of a partnership with the socio-economic research community;
Forecast demonstration projects, training and other capacity-building/infrastructure development are planned, as required by the Madrid action plan (March 2007) and the Brussels programme of action for LDCs adopted by the third UN Conference for LDCs (May 2001). These demonstration projects should include EPS and the next generation of high-resolution deterministic forecasting systems, and satellite application facilities (e.g. EUMETSAT-Meteosat Second Generation). These efforts will improve the limited visibility of NMHSs in some countries as it is an impediment to staff recruitment and development;
WWRP/THORPEX Africa will work with WMO/World Weather Watch/WMO Information System to assess the strengths and weaknesses of the Global Telecommunication System over Africa and to develop and implement a telecommunication project to network African university laboratories, research institutes, NMHSs, regional and international centres for data and exchange methods, tools and products. Such an effort will take into account the move to Internet and cellphone communication and strengthening of novel uses of local communication resources.
This article outlined three international efforts coordinated by the WMO to benefit African society by improving prediction capabilities. The first effort is the SWFDP programme. An appealing aspect of this project is the use of the cascading forecasting concept to deliver state-of-the-art operational prediction capabilities to the developing world at relatively low cost. The second project is SDS-WAS that is making a new forecast capability available in Africa. It also has strong links to end-users and serves as a focal for model improvement, product development and new ensemble capabilities for sand- and duststorms. The project has benefited from national resources to establish a regional centre Spain and from cooperation between partners.
The third project, THORPEX-Africa, is a long-term vision to improve the prediction and research capabilities within Africa in contrast to the previous efforts that rely more heavily on capabilities outside Africa. A long-term development project requires buy in from the NMHSs and the African users of environmental prediction products. Even with the assumed strong contribution from nearly all components of WMO, a coordinated effort to generate resources is needed to make the vision of THORPEX Africa a reality. One step in resource mobilization, as well as to strengthen links and benefits to end-users, is the recent establishment of THORPEX-Africa as a Group on Earth Observations task. This article seeks to gain feedback from the broader Africa community and other partners to implement this vision.
We thank the participants without whose contributions, these WMO efforts for Africa would not have been possible.
Afiesimama, E.A., 2007: Weather forecasting in Africa over the last 25 years. WMO Bulletin, 56 (1), 49-51.
Hollingsworth, A. et al., 2005: The transformation of earth-system observations into information of socio-economic value in GEOSS. Q.J. R. Meteorol. Soc., 131, 3493-3512.
Intergovernmental Panel on Climate Change, 2008: Fourth Assessment Report: Climate Change 2007—The Physical Basis. Cambridge University Press.
Poolman, E., H. Chikoore and F. Lucio, 2008: Public benefits of the Severe Weather Forecasting Demonstration Project in south-eastern Africa. WMO newsletter MeteoWorld.
Shapiro, M.A. and A.J. Thorpe, 2004: THORPEX International Science Plan. WMO/TD-No. 1246, WWRP/THORPEX, No. 2, 51 pp.
THORPEX/International Core Steering
Committee, 2005: THORPEX International Research Implementation Plan, WMO/TD-No. 1258, WWRP/THORPEX, No. 4, 95 pp.
Uppala, S.M. et al., 2005: The ERA-40 re-analysis. Q. J. R. Meteorol. Soc., 131, 2961-3012.
1African Centre for Meteorological Applications to Development
2Earth Sciences Department, Barcelona Supercomputing Center, Centro Nacional de Supercomputación
3Director del Centro de Investigación Atmosférica de Izaña, Agencia Estatal de Meteorologia
4Direction de la Météorologie nationale, Sénégal
5 Chief Forecaster: Disaster Risk Reduction, South African Weather Service, Pretoria, South Africa
6 Chair Africa Regional Programme, International Research Institute for Climate and Society (IRI)