Influence of Barents Sea Ice in May on the West African Summer Monsoon and its possible mechanisms

Datti, A. D., Zeng, G., Chen, C., Monerie, P.-A. ORCID: https://orcid.org/0000-0002-5304-9559 and Matazu, M. B. (2026) Influence of Barents Sea Ice in May on the West African Summer Monsoon and its possible mechanisms. Atmospheric Research, 338. 108983. ISSN 0169-8059

Abstract/Summary

The West African Summer Monsoon (WASM) is a key driver of rainfall in West Africa, significantly impacting agriculture, water resources, and livelihoods. As the WASM is sensitive to global warming and climate variability, it is essential to understand the factors driving its variability. Previous studies have suggested a potential influence of Arctic sea ice concentration (SIC) on tropical climate. However, the impact and underlying mechanisms linking Arctic SIC to the WASM remain unclear. Therefore, this study examines the influence of Barents SIC in May on the WASM over the period 1981–2023. We show a significant positive relationship between the WASM and the Barents SIC in May. Positive Barents SIC can initiate a Rossby wave train that propagates eastward across the North Pacific, enters North America, and extends over the North Atlantic toward the Tropical North Atlantic. The wave train transfers energy and momentum, creating positive geopotential height anomalies over the TNA, ultimately influencing SSTAs in the region. This linkage is primarily driven by changes in lower-tropospheric atmospheric circulation induced by Barents SIC variability. The resulting warm SSTA over the TNA persists through the summer months (June–September), sustaining its influence on large-scale circulation. Through air–sea interactions, the warm SSTA alters low-level atmospheric circulation, enhances convection over the TNA, and strengthens moisture transport toward West Africa, which contributes to increased WASM rainfall. The NCAR Community Atmosphere Model version 5.3 (CAM5.3) and the Parallel Ocean Program version 2 (POP2) can reasonably reproduce the observed mechanism through which increased Barents SIC influences the WASM.

Item Type	Article
URI	https://centaur.reading.ac.uk/id/eprint/129243
Official URL	https://www.sciencedirect.com/science/article/pii/...
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > NCAS Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Publisher	Elsevier
Download/View statistics	View download statistics for this item