EGU22-12602
https://doi.org/10.5194/egusphere-egu22-12602
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Multidecadal Modulations of Tropical Atlantic impact on ENSO

Belen Rodriguez-Fonseca1,2, Irene Polo Sanchez1, Elsa Mohino Harris1, Teresa Losada Doval1, Marta Martin del Rey1,2, Noel Keenlyside1, and Carlos Roberto Mechoso1
Belen Rodriguez-Fonseca et al.
  • 1Departamento de Física de la Tierra y Astrofísica, Universidad Complutense de Madrid, Madrid, 28040
  • 2Instituto de Geociencias IGEO (UCM-CSIC), Spain

Observational studies have reported that tropical Atlantic interannual variability impacts
on ENSO in different seasons and periods: Atlantic Ni ̃nos (AN) in boreal summer during
negative phases of the Atlantic Multidecadal Variability (AMV); and tropical north Atlantic
(TNA) in boreal spring during positive AMV. Nevertheless, this relation is not clear for the
whole observational record. This paper is an step forward towards understanding of tropical
Atlantic impacts on ENSO: how and when do they occur? Using observations and a pool of
preindustrial control simulations from the CMIP5 initiative we investigate the background
ocean and atmospheric conditions promoting these tropical interbasin connections.Periods
with a negative AN-ENSO connection appear characterized by a shallower thermocline
over the western Pacific and deeper in the east, together with an increase in interannual
SST variability over the tropics. Periods with a negative TNA-ENSO connection appear
characterized by a steeper thermocline in the Pacific and positive interhemispheric SST
gradient in the the Atlantic. A decrease in tropical Pacific atmospheric and ocean variability
characterizes these periods.

How to cite: Rodriguez-Fonseca, B., Polo Sanchez, I., Mohino Harris, E., Losada Doval, T., Martin del Rey, M., Keenlyside, N., and Mechoso, C. R.: Multidecadal Modulations of Tropical Atlantic impact on ENSO, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12602, https://doi.org/10.5194/egusphere-egu22-12602, 2022.

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