Origin of early‐spring central Pacific warming as the 1982–1983 El Ni?o precursor

摘要

>The extreme El Ni?o events, such as those which occurred in 1982–1983, 1997–1998, and 2015–2016, exerted devastating impacts in many parts of the globe. Hence, it is crucial to understand the precursors of such extreme events. Nevertheless, each El Ni?o event has its own characteristics even in the initiation. Here, we show that the development of early‐spring equatorial central Pacific warming forced by the increased solar radiation due to a suppressed convection was a crucial factor in developing the 1982–1983 extreme El Ni?o event. The central Pacific warming anomalies in the spring of 1982 were induced by atmospheric subsidence connected to the northern subtropical Pacific convection, subsequently reinforced by a reduced evaporative cooling via westerly anomalies. On the other hand, springtime warming anomalies over the equatorial central and eastern Pacific regions during other extreme El Ni?o events were induced mainly by oceanic dynamical processes.