1172 / 2024-09-20 15:57:17

Projected future changes of Ningaloo Niño under global warming

Indian Ocean,Ningaloo Nino,air-sea interaction

Session 65 - Oceanic-atmospheric processes over the Indian and western Pacific Oceans

Ningaloo Niño is an important climate mode in the southeastern Indian Ocean with far-reaching impacts on the climate and marine environment, but how Ningaloo Niño will change under global warming remains unclear. This study investigate the response of Ningaloo Niño to global warming using the CESM large ensemble (CESM-LE) projections and the Coupled Model Intercomparison Project phase 6 (CMIP6) model simulations. We find that the Ningaloo Niño will have a stronger magnitude, increased frequency, and a one-month delay in its broadened seasonal peak in the next century under the high greenhouse gas emissions scenario relative to the past century. A mixed-layer heat budget analysis indicates that the meridional advective feedback is the dominant driver for the Ningaloo Niño changes, with additional contributions from changes in latent heat flux forcing. The strengthening of meridional current and decreasing of latent heat loss are closely associated with enhanced coastal Bjerknes feedback and the wind-evaporation-SST feedback. Furthermore, given that the amplification of El Nino-Southern Oscillation (ENSO) and increasing of specific humidity saturation under global warming, we suggest that ENSO-related remote influences may contribute to the enhancing of Ningaloo Niño activity as well.