Anthropogenic warming regulates the life cycle of Madden-Julian Oscillation in Southeast Asia

Abstract:

The Madden-Julian oscillation (MJO) a tropical phenomenon lasting around 20-90 days that plays a crucial role in extreme weather events over tropics in particular Southeast Asia and Australia, as well as the global hydrological cycle through teleconnections. It is characterized by a large‐scale envelope of convection systems (i.e. cloud clusters and rain) propagating eastward along the equator. Under anthropogenic warming, MJO propagates faster and further eastward with intensified precipitation variability and triggers greater impacts on global hydrological cycle. Previous studies focused on the teleconnection impacts in Pacific-North America. However, how anthropogenic warming regulates the life cycle of Madden-Julian Oscillation in Southeast Asia remains unknown. Here, by analyzing several CMIP6 models that realistically simulate the MJO, we investigate the changing characteristics of MJO life cycle and the influence intensity under two anthropogenic warming scenarios: the intermediate forcing level scenario SSP2-4.5 and the relatively high emissions scenario SSP5-8.5. We further explore how the changes in the MJO life cycle impact the climate particularly precipitation extremes in Southeast Asia. Our study highlights the fundamental role of MJO in shaping the climate in Southeast Asia, and calls for precautions and adaption strategies to mitigate the future adverse effect aggravating weather variability on local agriculture and economy.