FESTIVAL · From boreal spring to summer Tropical Atlantic inter-annual variability
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-01-16 → 2021-01-15
- EU contribution
- €158,122
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
From boreal spring to summer Tropical Atlantic inter-annual variability
The tropical Atlantic variability is thought to be controlled by two air-sea couple patterns, the Meridional (MM) and Equatorial Mode (EM), peaking in boreal spring and summer respectively. Both modes exhibit pronounced environmental and socioeconomic impacts on the surrounding countries. Previous studies suggested possible interaction between these modes, but without reaching a consensus about the underlying mechanisms and the timing of the connection. Thus, determining the existence of MM-EM connection is essential to completely understand the tropical Atlantic variability and anticipate its climate impacts. Thus, FESTIVAL project aims to investigate the connection between the traditional MM and EM, understanding the underlying air-sea mechanisms and its multidecadal modulation. The main conclusions achieved in FESTIVAL project are: 1) Evolving modes, from winter to summer, emerge in the tropical Atlantic basin during the 20th century. 2) The evolving modes interact between them at inter-decadal time scales along the historical record, associated with large-scale ocean decadal patterns. 3) The North Tropical Atlantic SSTs act as a precursor of equatorial Atlantic variability up to 6 months in advance. 4) An oceanic mechanism based on the boundary-reflection of Rossby wave into an equatorial Kelvin wave is the main responsible to connect the MM and EM. However, its effectiveness in generating equatorial SST variability during summer months is modulated by the local wind forcing. 5) The evolving modes have a pronounced impact over the precipitation regime over Africa and South-America that changes from winter to summer season.
Data: CORDIS, © European Union
Project objective
The economy of tropical Atlantic countries is based, to a large extent, on agriculture and fisheries, which are highly climate-dependent. Moreover, climate variations affect the incidence and transmission of certain diseases (i.e: Malaria), which strongly impact on the health and livelihood of West Africa and South America populations. Consequently, the tropical Atlantic variability (TAV) has important environmental and socio-economic impacts. Two dominant air-sea coupled patterns govern the TAV: the Meridional Mode (MM) and the Equatorial Mode (EM). The MM presents an inter-hemispheric sea surface temperature (SST) gradient during boreal spring, while the EM is characterized by warmer (cooler) SST anomalies in the eastern equatorial Atlantic in boreal summer.FESTIVAL project aims to investigate the existence of the MM-EM connection from a novel non-stationary approach. The air-sea processes responsible of this interaction will be determined at different time scales. The MM and EM have profound imprints on the climate of adjacent and remote areas. If the MM-EM connection is established, their individual climate teleconnections would change, impacting on the precipitation anomalies over South America and Sahel, on the strength of the Northwest African and Angola-Benguela upwellings and on the Euro-Mediterranean climate. Moreover, the MM would act as a precursor of the EM pattern, enhancing its predictability, which still remains a challenge for the scientific community. Thus, within FESTIVAL, we will investigate the climate impact of the MM-EM link and will assess the predictive skill of the EM from the tropical Atlantic spring variability.The natural decadal variability and the externally-forced Global Warming could modify the background state, modulating the TAV and in turn the MM-EM connection. In FESTIVAL, we will properly assess the role played by the low-frequency variability in the key mechanisms for activating the MM-EM connection.
Original text from CORDIS.
Participants
- AGENCIA ESTATAL CONSEJO SUPERIOR DE INVESTIGACIONES CIENTIFICAS · MadridCoordinatorSpain
Links
Data: CORDIS, © European Union