[AOS23-P04] The extraordinary Atlantic Nino of 2019/2020
キーワード：equatorial Atlantic, Atlantic Nino, global warming
From December 2019 onward there was an increase in equatorial Atlantic sea-surface temperatures (SST), with anomalous warming in the eastern part of the basin. While such interannual warm events (also known as Atlantic Ninos) are a common occurrence in the region, the 2019/2020 event stands out for two reasons: 1) It is the warmest event to occur in at least two decades, thereby punctuating a period of relatively low variability in the equatorial Atlantic. 2) Its timing was unusual, as Atlantic Niños almost exclusively develop in boreal spring and peak in summer.
Here we analyze SST, surface winds, surface heat fluxes, and sea-surface height to explain the unusual development of the 2019/2020 event. Preliminary results suggest that it was primarily driven by surface heat fluxes rather than by ocean dynamics. We further attempt to put this event into the context of previous studies that have argued for a decrease of equatorial Atlantic variability in recent decades.
Here we analyze SST, surface winds, surface heat fluxes, and sea-surface height to explain the unusual development of the 2019/2020 event. Preliminary results suggest that it was primarily driven by surface heat fluxes rather than by ocean dynamics. We further attempt to put this event into the context of previous studies that have argued for a decrease of equatorial Atlantic variability in recent decades.