[M-IS14] Paleoclimatology and paleoceanography

[MIS14-06] Variations in the Westerly wind path over East Asia during MIS11

*Karen Okada¹, Shin Toyoda¹, Kana Nagashima² (1.Okayama University of Science, 2.Japan Agency for Marine-Earth Science and Technology)

Keywords:dust, ESR, westerlies, marine sediment

The westerlies, which characterize the climate of mid-latitude regions, respond sensitively to changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC). Recent paleoclimate studies have reported that large-scale AMOC weakening events occurred repeatedly during past interglacial periods (oxygen isotope stages MIS 1, mid-5e, 7e, 9e, 11e). In the present study we aim to reconstruct the variations in the westerlies over East Asia during MIS 11, when several AMOC weakening events were observed (Galaasen et al. 2020).
We evaluated the westerly wind paths during MIS 11 by reconstructing the sources of Asian dust contained in the KR07-12 PC-5 core collected from the Japan Sea, since the relative contribution of Asian dust from the two typical East Asian deserts, the Taklimakan and Gobi deserts, is sensitive to the westerly wind position. For this purpose, we measured Electron Spin Resonance (ESR) intensity of the E₁’ center of quartz in Japan Sea sediments utilizing the ESR intensity differences between the two deserts (Sun et al., 2007; Nagashima et al. 2011). In the presentation, we will discuss the variability of ESR intensity during MIS 11 and the possible responses of the westerly wind to the AMOC change during the past warm period.