CC BY-NC 4.0 UnportedSingh, M.Krishnan, R.Goswami, B.Choudhury, A. D.Swapna, P.Vellore, R.Prajeesh, A. G.Sandeep, N.Venkataraman, C.Donner, R. V.Marwan, N.Kurths, J.2022-11-212022-11-212020https://oa.tib.eu/renate/handle/123456789/10377http://dx.doi.org/10.34657/9413Coupling of the El Niño-Southern Oscillation (ENSO) and Indian monsoon (IM) is central to seasonal summer monsoon rainfall predictions over the Indian subcontinent, although a nonstationary relationship between the two nonlinear phenomena can limit seasonal predictability. Radiative effects of volcanic aerosols injected into the stratosphere during large volcanic eruptions (LVEs) tend to alter ENSO evolution; however, their impact on ENSO-IM coupling remains unclear. Here, we investigate how LVEs influence the nonlinear behavior of the ENSO and IM dynamical systems using historical data, 25 paleoclimate reconstructions, last-millennium climate simulations, large-ensemble targeted climate sensitivity experiments, and advanced analysis techniques. Our findings show that LVEs promote a significantly enhanced phase-synchronization of the ENSO and IM oscillations, due to an increase in the angular frequency of ENSO. The results also shed innovative insights into the physical mechanism underlying the LVE-induced enhancement of ENSO-IM coupling and strengthen the prospects for improved seasonal monsoon predictions.enghttps://creativecommons.org/licenses/by-nc/4.0/500Angular frequenciesClimate sensitivityIndian subcontinentsNon-linear phenomenaPaleoclimate reconstructionPhase synchronizationSouthern oscillationSummer monsoon rainfallArticle