Precipitation forecasts are very useful for agricultural areas such as the Sahel. However, while there are reliable models and measurements for Europe, a targeted use of weather information for Africa remains a vision for the future. Scientists from the Karlsruhe Institute of Technology (KIT) and the Heidelberg Institute for Theoretical Studies (HITS) are therefore researching methods to improve precipitation forecasts for Africa.
When will it rain, where, and how much? Reliable weather forecasts are now taken for granted by people in Western countries. While there are currently reliable predictive models and weather observations for these regions, the state of affairs is much worse for many areas of Africa. In a recently published study, the team of scientists under the direction of Peter Knippertz at the Institute of Meteorology and Climate Research (KIT) and Tilmann Gneiting at the Institute of Stochastics (KIT) and the Heidelberg Institute for Theoretical Studies (HITS) reveals why progress made in weather forecasting in Europe and North America does not directly translate to Africa and what science can do to tackle this problem. The study was developed as part of the collaborative research center “Waves to Weather”, which is funded by the German Research Foundation (DFG) and deals with fundamental questions concerning the predictability of weather.
Precipitation forecasts are of great socio-economic benefit to agricultural societies, such as those found in northern tropical Africa, and especially in areas with low total, but intense rainfall of short duration, such as the West African Sahel. The inaccurate or missing forecasts for these regions stem from several factors: On the one hand, the available data are considerably less than in Europe due to a significantly smaller number of weather stations in the Sahel. On the other hand, currently available computer models hardly provide reliable forecasts in Africa. The problem is that the existing models are adjusted to the characteristics and climatic parameters of certain regions – in this case, mostly Europe and North America – and are only partly transferrable to areas dominated by tropical thunderstorms.
“Weather forecasts have improved enormously in Europe, which is first and foremost due to sustainable investments in research,” Gneiting explains. “We wondered whether these advances could also be seen in weather forecasts for the tropics.” The research team therefore conducted for the first-time a large-scale predictive study for northern tropical Africa. The scientists compared precipitation forecasts from weather models calculated via supercomputers with forecasts made purely statistically via satellite-based and ground data. In addition, they examined whether a complex statistical combination of these two methods allows for better prognoses.
The results reveal that the predictions of the numerical models for Africa are not nearly as reliable as they are for Europe despite the great importance of precipi-tation forecasts for the African tropics. The results of these analyses have consequences for research and politics. “Investing in the improvement of weather models for Africa is a modern form of development assistance,” Knippertz summarizes. He goes on to explain that in the UK, part of the state development assistance budget has already been dedicated to weather services and universities in order to develop models that will work well in Africa.
Prof. Dr. Peter Knippertz
Institute of Meteorology and Climate Research (IMK)
Karlsruhe Institute of Technology (KIT)
Prof. Dr. Tilmann Gneiting
Computational Statistics (CST) group
Heidelberg Institute for Theoretical Studies (HITS)
Karlsruhe Institute of Technology (KIT) pools its three core tasks of research, higher education, and innovation in a mission. With about 9,300 employees and 25,000 students, KIT is one of the big institutions of research and higher education in natural sciences and engineering in Europe. KIT – The Research University in the Helmholtz Association
HITS, the Heidelberg Institute for Theoretical Studies, was established in 2010 by physicist and SAP co-founder Klaus Tschira (1940-2015) and the Klaus Tschira Foundation as a private, non-profit research institute. HITS conducts basic research in the natural, mathematical, and computer sciences. Major research directions include complex simulations across scales, making sense of data, and enabling science via computational research. Application areas range from molecular biology to astrophysics. An essential characteristic of the Institute is interdisciplinarity, implemented in numerous cross-group and cross-disciplinary projects. The base funding of HITS is provided by the Klaus Tschira Foundation.