Publications

Smiatek, G; Kunstmann, H (2023). Potential Impact of the Pan-African Great Green Wall on Sahelian Summer Precipitation: A Global Modeling Approach with MPAS. EARTH INTERACTIONS, 27(1), e220013.

Abstract
The pan-African Great Green Wall for the Sahara and the Sahel initiative (GGW) is a reforestation pro-gram to reverse the degradation of land. We investigate characteristics of mean precipitation due to proposed land-use changes to woody savannah with three hypothetical courses of the GGW, with an area between 0.8 and 1.25 million km2, and between the 100-and 400-mm isohyets. The global Model for Prediction Across Scales (MPAS) was applied for this in-vestigation, employing ensembles with 40 members for the rainy season from June to September and 50 members for August when precipitation is at its peak. In comparison with the observational reference, the results show that a wet bias on the order of 33% in the eastern Sahel and a moderate dry bias of 241% in the western Sahel are present in the MPAS simulations. Our simulations do not provide any significant evidence for GGW-induced changes in the characteristics of the summer precipitation, for positive changes within the Sahel supporting the forestation activities, or for potentially adverse changes in the neighboring regions. Changes are present at the regional scale, but they are not significant at the 5% level. Also, changes simulated for further hydrometeorological variables such as temperature, radiation fluxes, or runoff are comparatively small.

DOI:
10.1175/EI-D-22-0013.1

ISSN:
1087-3562