2026-06-27T10:55:38Zhttps://docta.ucm.es/rest/oai/requestoai:docta.ucm.es:20.500.14352/60182024-09-04T14:33:53Zcom_20.500.14352_14col_20.500.14352_15
Docta Complutense
author
Martín Del Rey, Marta
author
Polo Sánchez, Irene
author
Rodríguez De Fonseca, María Belén
author
Lazar, Alban
author
Losada Doval, Teresa
2023-06-16T15:15:41Z
2023-06-16T15:15:41Z
2019-11
2169-9275
10.1029/2019JC015030
https://hdl.handle.net/20.500.14352/6018
http://dx.doi.org/10.1029/2019JC015030
https://agupubs.onlinelibrary.wiley.com
A recent study has brought to light the co‐existence of two distinct Atlantic Equatorial Modes during negative phases of the Atlantic Multidecadal Variability: the Atlantic Niño and Horse‐Shoe (HS) mode. Nevertheless, the associated air‐sea interactions for HS mode have not been explored so far and the prevailing dynamic view of the Atlantic Niño has been questioned. Here, using a forced ocean model simulation, we find that for both modes, ocean dynamics is essential to explain the equatorial SST variations, while air‐sea fluxes control the off‐equatorial SST anomalies. Moreover, we demonstrate the key role played by ocean waves in shaping their distinct structure and timing. For the positive phase of both Atlantic Niño and HS, anomalous westerly winds trigger a set of equatorial downwelling Kelvin waves (KW) during spring‐summer. These dKWs deepen the thermocline, favouring the equatorial warming through vertical diffusion and horizontal advection. Remarkably, for the HS, an anomalous north‐equatorial wind stress curl excites an upwelling Rossby wave (RW), which propagates westward and is reflected at the western boundary becoming an equatorial upwelling KW. The uKW propagates to the east, activating the thermocline feedbacks responsible to cool the sea surface during summer months. This RW‐reflected mechanism acts as a negative feedback causing the early termination of the HS mode. Our results provide an improvement in the understanding of the TAV modes and emphasize the importance of ocean wave activity to modulate the equatorial SST variability. These findings could be very useful to improve the prediction of the Equatorial Modes.
eng
Ocean dynamics shapes the structure and timing of Atlantic Equatorial Modes
journal article
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https://docta.ucm.es/bitstreams/ed1fdfee-e84e-4caf-a5b0-65bbc24e0b82/download
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c1f2e5a3fa98db8692c41834cf322bcc
11162534
application/pdf
losadadoval02libre.pdf
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75f1300db21738d6356068cd5d01aaf3
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losadadoval02libre.pdf.txt