Climate and environmental changes over Ecuadorian Amazon documented by d18O records in speleothems

• Grant number: 20/16321-4
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): March 01, 2021
• Effective date (End): November 30, 2021
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Acordo de Cooperação: NSF and NSF's Partnership for International Research and Education (PIRE)
• Principal Investigator: Francisco William da Cruz Junior
• Grantee: Angie Patricia Jiménez Iñiguez
• Host Institution: Instituto de Geociências (IGC). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 17/50085-3 - PIRE: climate research education in the Americas using tree-ring speleothem examples (PIRE-CREATE), AP.TEM

Abstract

The South America Monsson System (SAMS) and Intertropical Convergence Zone (ITCZ) are the main responsible by convection over tropical and extratropical regions of South America. Despite several studies have shown that both systems are sensitive to solar variability the interrelationship between SAMS and ITCZ was not well documented for the last millennium over the ITCZ Region in South America. Reconstructing tropical hydroclimate history has been difficult, particularly in the Amazon Basin, one of Earth's major centers of deep atmospheric convection, largely because most study sites are located on the periphery of the basin and interpretations can be complicated by sediment preservation, uncertainties in chronology, and topographical setting. For a better comprehension of the ITCZ variability in the past it is proposed a new study of paleoclimate reconstruction involving ´18O and ´13C on speleothems collected in Jumandy cave in the western Amazon River basin (Ecuador). The stalagmites for this study will be compared with the previously published ´18O records from Peruvian Andes and from southern border of Amazon Basin for the understanding of ITCZ evolution over the Andean Cordillera. Despite of recent advances on the studies related with ITCZ variability in the past, the paleoclimate picture over the ITCZ region is still incomplete. This research project aims to provide high resolution paleoclimate records to characterize the paleorainfall data over ITCZ region in Ecuador. It will be important for the understanding of the flux of moisture over the Amazon Basin, in consequence will provide a key data set for studies of the ITCZ and its relationship with SAMS and radiative forcing. (AU)