Banca de QUALIFICAÇÃO: PAULA GABRIELA FERNANDES AGOSTINHO

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
DISCENTE : PAULA GABRIELA FERNANDES AGOSTINHO
DATA : 29/05/2019
HORA: 08:30
LOCAL: AUDITORIO CCET
TÍTULO:

CLIMATIC RECORD IN SIDERASTREA STELLATA SP. DO ATOL DAS ROCAS, RN, BRAZIL

PALAVRAS-CHAVES:

Stable Isotopes, Sclerochronology; Ocean-atmosphere Interaction.

PÁGINAS: 65
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Oceanografia
SUBÁREA: Oceanografia Física
ESPECIALIDADE: Interação do Oceano com a Atmosfera
RESUMO:

The historical record of climatic events in Brazil is relatively short, rarely exceeding 100 years in duration, especially when we take into account data from oceanic regions. The scarcity of records makes it difficult to better understand the patterns of climate variability existing. As an alternative to better understand the variability patterns of the climate system one can resort to pre-instrumental records (sedimentary, biological and biogeochemical). Corals are organisms that throughout their growth are able to record in their carbon skeleton information about the environment that has developed. In this context, this work intends to verify the relation of the variability of climatic events and the previous environmental conditions in the ocean water recorded during the development of a Brazilian endemic coral colony, Siderastrea stellata sp. A sample of this species was collected in the Atol das Rocas in 2013, allowing geochemical analysis with isotopic markers (δ18O, δ13C and Sr/Ca) that are directly related to sea water temperature. These markers will be used as proxies for the reconstruction of the sea surface temperature (SST) of Atol das Rocas during the period of colony growth (56 years). Through the analysis of some local and remote oceanic-atmospheric indexes (Inter-tropical Convergence Zone, El Niño / La Niña, and Atlantic Dipole), it is expected to verify changes in the coral geochemical records, revealing its ability to record climatic variability. As one of our goals, we intend to reconstruct the SST variations through the geochemical records of Siderastrea stellata sp. In this process a satellite database for temperature will be used in order to establish a linear regression with the geochemical data as well as the validation of the proposed model. Geochemical dating of the colony was performed using a high-precision dating method (²³⁰U-Th). Time series analyzes will be carried out to compare the historical climatic variability and the one observed in the corals. Possible trends in the data will also be investigated through correlations with the temperature increases observed in the last decades (Mann-Kendall test). It was hoped that the results obtained in this project allow correlating the growth rate of this species and its geochemical records with recent climatic events, in order to contribute to the formation of a climate database that allows a better understanding of tropical insular environments and their variability.

MEMBROS DA BANCA:
Presidente - 1858120 - DAVID MENDES
Interno - 1164414 - WEBER ANDRADE GONCALVES
Externo ao Programa - 2276514 - MARCIO MACHADO CINTRA
Externo à Instituição - NATAN SILVA PEREIRA - UNEB