EGU23-7348, updated on 25 Feb 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

An Energy Transport View of ENSO Responses to Volcanic Forcing

Shih-Wei Fang and Claudia Timmreck
Shih-Wei Fang and Claudia Timmreck
  • Max-Planck-Institut für Meteorologie, The Atmosphere, Hamburg, Germany (

El Niño-Southern Oscillation (ENSO) is one of the major climate phenomena impacting the globe. When a volcanic eruption happens, how ENSO will respond has still no consensus in proxy data though climate models tend to have an El Niño tendency. In this study, using 100 members of diverse (in locations and magnitude) idealized volcanic forcing ensembles, we found that the ENSO responses to north and south extra-tropical eruptions are related to the energy transport to the cooling hemisphere and involve direct and indirect responses through atmospheric and oceanic transport. The north extratropical forcing leads to more El Niño up to three years after eruptions, which is related to the direct atmospheric responses of the southward movement of ITCZ for transporting more energy to the north. The indirect oceanic transport then takes over afterward, leading to more La Niña due to more upwelling in the equatorial eastern Pacific. The south extra-tropical eruptions have less El Niño tendency due to the northward replacement of ITCZ. As the indirect oceanic transport also results in equatorial mean state changes, which may lead to distinct ENSO responses. The long-term ENSO responses from extra-tropical cooling will also be investigated through the simulations from the Extratropical-Tropical Interaction Model Intercomparison Project (ETIN-MIP) experiment.

How to cite: Fang, S.-W. and Timmreck, C.: An Energy Transport View of ENSO Responses to Volcanic Forcing, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-7348,, 2023.