Contributions to the study of southern hemisphere Late Pleistocene climatic variability through the characterization of South American dust sources and the related sedimentary deposits

DIEGO GAIERO

Conferencia; Blowing South: Southern Hemisphere Dust Symposium; 2021

The need to increase knowledge in aspects related to the climatic conditions prevailing over the southern hemisphere (SH) during the last glacial-interglacial periods, boosted the interest of the scientific community to investigate the physicochemical/isotopic characteristics of sediments deflated from southern South America (SSA) and to recognize them in key sedimentary deposits of the region (e.g., Pampas, Patagonian shelf, Southern Ocean; Antarctica). Due to its geographic position, SSA represents a key area that could help to unravel some questions related to past climatic changes. In particular, the region has the most significant loess deposits in the SH and, this proximal aeolian dust record witnesses the importance of wind erosion affecting different latitudinal and topographic areas in the “arid diagonal” of SSA, and could shed light on the past atmospheric circulation over the SH. Furthermore, a huge amount of this aeolian material has been atmospherically transported to remote areas, taking both essential micronutrients to the ocean and a fingerprint representing a particular SSA region, useful to trace back the origin of dust in paleo-climatic archives recovered from the Southern Ocean and Antarctica. During the last 20 years, we gained insight into aspects related to modern/past dust dynamics in the region, characterizing its textural, chemical/isotopic compositions and, contributing to the interpretation of how the atmospheric circulation over the region could have changed during the last climatic cycles. In this talk, I present a review of these research activities showing the main results obtained by our group and pointing out the futures perspectives that could help the international scientific community working on this issue to improve the state-of-the-art related to the role of the SH in the context of global future climate change scenarios.