Elevated dust depositions in West Asia linked to ocean–atmosphere shifts during North Atlantic cold events

Safaierad, R; Mohtadi, M ✉; Zolitschka, B; Yokoyama, Y; Vogt, C; Schefuß, E

Angol nyelvű Tudományos Szakcikk (Folyóiratcikk)
  • Szociológiai Tudományos Bizottság: A
  • Gazdaságtudományi Doktori Minősítő Bizottság: C
  • SJR Scopus - Multidisciplinary: D1
North Atlantic cold events in the past have been shown to cause large-scale atmospheric reorganizations. Results of our dust record from southeastern Iran, which is highly susceptible to capture dust storms from North Africa and the Arabian Peninsula—the largest dust source on Earth—show a direct link between North Atlantic cooling and enhanced eastward dust transport from the Arabian Peninsula and North Africa. This finding suggests that climate conditions over western Asia during these cold events were controlled by a southward shift in the winter position of the Northern Hemisphere westerlies and more susceptible to variations in the North American winter ice cover.Rapid North Atlantic cooling events during the last deglaciation caused atmospheric reorganizations on global and regional scales. Their impact on Asian climate has been investigated for monsoonal domains, but remains largely unknown in westerly wind-dominated semiarid regions. Here we generate a dust record from southeastern Iran spanning the period 19 to 7 cal. ka B.P. We find a direct link between frequent occurrences of dust plumes originating from the Arabian Peninsula and North Africa and rapid southward shifts of the westerlies associated with changes of the winter stationary waves during Heinrich Stadial 1, the Younger Dryas, the Preboreal Oscillation, and the 8.2-ka event. Dust input rises and falls abruptly at the transitions into and out of these cooling events, which we attribute to changes in the ocean circulation strength that are modulated by the North Atlantic winter sea-ice cover. Our findings reveal that waxing and waning of North American ice sheets have a stronger influence than those of European ice sheets on the winter climate over West Asia.
Hivatkozás stílusok: IEEEACMAPAChicagoHarvardCSLMásolásNyomtatás
2020-09-19 02:31