Coastal countries in West Africa (WA) heavily rely on the ocean, which is a major source of food and employment. Located off Mauritania, Senegal and Guinea, the southern Canary Upwelling system (SCUS) is among the most productive oceanic areas in the world. The SCUS and its ecosystems are under rising pressure, due to economic development, demography, and presumably the effect of climate change. Yet, the SCUS variability remains largely an uncharted territory. Our project aims to gain understanding on SCUS climate variability and change, and hence to explore SCUS vulnerability at the horizon 2050.
The meridional migration of the inter-tropical convergence zone (ITCZ) being the dominant forcing of the SCUS variability on seasonal time scales, this project offers a strong complementarity with the historical activities of AMMA on the monsoon variability and related impacts. One of our main goals will be to investigate the degree to which the upwelling and monsoon seasons are anti-correlated at other timescales, i.e. how a stronger, longer or later monsoon (and thus cropping) season translate in terms of upwelling (and thus fishing) season.
This link may occur through large-scale climate variability and/or the ITCZ anomalous migration. In relation to the topic of high impact weather emphasized in AMMA2050, we also plan to investigate the regional atmospheric conditions leading to synoptic episodes of trade wind intensification, the related upwelling response and the evolution of their frequency at the 2050 horizon.
Such episodes are indeed believed to have detrimental effects because they:
1) Endanger artisanal fishermen (or prevent fishing)
2) Tend to disperse marine organisms and transport them offshore, where they are no longer available for the coastal socio-ecosystem
Overall, we propose to help build an expert judgement on future of the SCUS using a series of tools, from local observations to regional and global climate models.