EGU2020-22335
https://doi.org/10.5194/egusphere-egu2020-22335
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Multidecadal Modulations of ENSO influence on cyclogenesis in the Tropical Atlantic

Adama Badiane1, Belén Rodríguez-Fonseca2,3, Teresa Losada2, Abdou Lahat Dieng1, and Saidou Moustapha Sall1
Adama Badiane et al.
  • 1Laboratoire de Physique de l’Atmosphère et de l’Océan -Siméon Fongang, Ecole Supérieure Polytechnique de l’Université Cheikh Anta Diop (UCAD), Dakar,
  • 2Universidad Complutense de Madrid, Departamento de Física de la Tierra y Astrofísica, Facultad de Físicas, 28040 Madrid, Spain
  • 3Instituto de Geociencias IGEO, UCM-CSIC . Madrid, Spain

The impact of ENSO (El Niño Southern Oscillation) events on the cyclogenesis of the eastern tropical North Atlantic is highlighted, focusing on decadal variations of the interannual relationship at the Senegalese coast, which is the main cyclone development region (MDR). SST anomalies in the Equatorial Pacific associated with ENSO events affect vertical wind shear over the eastern Atlantic, by inducing strong subsidence of dry air over the eastern Atlantic which tends to inhibit deep convection and thus be unfavorable to cyclonic activity. Based on 20yr- correlations between the number of cyclones that are born in the MDR and ENSO index, we have selected two different periods of study (period1: 1950-1969; and period2: 1996-2015).The results show that period2 presents the highest scores of negative correlations between ENSO and tropical Atlantic cyclogenesis. Although there is an intensification of ENSO events during period2 compared to period1, we have found that decadal changes in climatology have a more significant effect on the MDR than the interannual changes. Additionally, the changes in the interannual signal appear to be related to the concomitant action of interannual SST anomalies over the whole tropical basins.

How to cite: Badiane, A., Rodríguez-Fonseca, B., Losada, T., Dieng, A. L., and Sall, S. M.: Multidecadal Modulations of ENSO influence on cyclogenesis in the Tropical Atlantic, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-22335, https://doi.org/10.5194/egusphere-egu2020-22335, 2020