Fingerprint of volcanic forcing on the ENSO-Indian monsoon coupling

Author(s):Show less -

Singh, 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.

• Document type: Journal article
• Source: SCIENCE ADVANCES; v. 6, n. 38, p. 11-pg., 2020-09-01.

Abstract

Coupling of the El Nino-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. (AU)

• FAPESP's process: 15/50122-0 - Dynamic phenomena in complex networks: basics and applications
• Grantee: Elbert Einstein Nehrer Macau
• Support Opportunities: Research Projects - Thematic Grants