|By: Africa Rainfall Project research team|
|Delft University of Technology|
|22 Dec 2020|
The scientists behind the Africa Rainfall Project give us a status update on the research and outline their plans for 2021 in this article.
In sub-Saharan Africa, 95 percent of agriculture depends on rainfall, which makes accurate weather forecasts absolutely crucial. However, because rainfall in this area is often localized—sometimes almost at the level of one farm—it's difficult to forecast accurately with satellite data, which show larger weather patterns.
Through this project, we're creating high-resolution computer simulations of localized rainstorms in sub-Saharan Africa. Thanks to the massive, crowdsourced computing power from World Community Grid, we can run simulations at a much higher resolution—exactly what's needed for localized rainstorms. This has never been done for rainstorms in this region.
Status and results
The Africa Rainfall Project is running well. About one quarter of the planned simulations have been completed, thanks to the many volunteers of the World Community Grid.
This means we can already start looking at the first results covering most of the rainy season in West Africa. These results do indeed show the onset of the rainy season, when monsoon winds carry moisture from the Gulf of Guinea onto the continent, where it rains out. Most of the rainfall fell during convective storms, which develop rapidly over relatively small areas. It is because of this localized nature of rainfall in Africa that the Africa Rainfall Project is necessary.
By using the computational power of the machines of volunteers, it becomes possible to zoom in and resolve these rainfall producing processes at a very fine scale. At its finest scale, the resolution is a grid with cells of one by one kilometer.
Presentation at the Fall Meeting of the American Geophysical Union
Every year, in the first half of December, the American Geophysical Union (AGU) holds its Fall Meeting. Typically, more than 20,000 scientists from all over the world gather to exchange results and meet up to make new plans for the year. This year, the meeting should have taken place in San Francisco, but it was moved online due to COVID-19.
The Africa Rainfall Project was presented during this occasion to scientists specifically interested in African weather and climate in the session on “Climate Variability and the African Environment, Water Resources, and Food Security.” The session was lively and well-attended, with interesting discussions following the brief online presentations.
One interesting result that was discussed concerned the optimal scale at which to simulate convective rainstorms. Some people argued that a three kilometer resolution might be sufficient, while others preferred the finer one kilometer grid This is an important science question that the project will be able to answer soon.
The Africa Rainfall Project produces many files with weather simulation results. In the end, we expect to receive close to four billion files! It is not trivial to store and organize so many files, let alone make them readily accessible online. The amount of data produced is about 0.5 petabytes, or, in more nostalgic terms, a pile of over 370 million 3.5-inch floppy disks. That pile would weigh over 6,700 tons and would be over 1,200 km high.
With grants from SURF, a cooperative association of Dutch educational and research institutions, and Delft University of Technology, the files will be consolidated and stored efficiently. The next step will be to develop a web page where everybody can select an area of interest to visualize the results of the Africa Rainfall Project. This is expected to come online early 2021 and will give all volunteers the opportunity to look at the overall results so far.
Thank you to everyone who is supporting the Africa Rainfall Project.