Climate model experiments on the 4.2 ka event: The impact of tropical sea-surface temperature anomalies and desertification

The 4.2 ka event is one of the most prominent climate events Holocene. In this study, several model experiments were performed to investigate its causal mechanism. focus in these was on impact anomalies sea surface temperatures (SSTs) associated with enhanced El Nino activity, as has been proposed an important driver for event. Six different SST anomaly scenarios considered, covering tropical sectors Pacific, Indian, and Atlantic Oceans. addition, possible desertification Northern Africa Arabia taken into account. results evaluated against global humidity signature provided by proxy-based reconstructions from 129 sites. It found that a scenario warm Pacific SSTs cold provides best match proxies. This experiment produces significant decreases precipitation South Asia, West East Africa, increases America northwest North America. These are partly forced strong increase albedo Arabia, leading regional cooling more stable atmospheric conditions, moisture transport related land-sea thermal contrast. Based results, it caused anomalies, drying assisted ongoing Arabia.