Banca de DEFESA: PAULA GABRIELA FERNANDES AGOSTINHO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : PAULA GABRIELA FERNANDES AGOSTINHO
DATE: 23/09/2020
TIME: 08:30
LOCAL: VÍDEOCONFERENCIA
TITLE:

Isotopic Response in Siderastrea stellata to Climate Variability in the Tropical Atlantic

KEY WORDS:

Isotopic cycles; Coral Geochemistry; Paleothermometer; Climate changes; Oceanatmosphere interaction.

PAGES: 99
BIG AREA: Ciências Exatas e da Terra
AREA: Oceanografia
SUBÁREA: Oceanografia Física
SPECIALTY: Interação do Oceano com a Atmosfera
SUMMARY:

In the current climate scenario, the need to provide accurate projections of future weather and climate evolution, demand for long-term historical environmental data. The historical record of climate events in Brazil is relatively short, rarely exceeding 100 years in duration, mainly with respect to data from oceanic regions. The scarcity of records makes it difficult to better understand the patterns of existing climate fluctuations. Corals are able to record information on tropical ocean history in addition to instrumental recording. Because they are extremely sensitive to changes in climatic conditions, coral development is affected. In their skeletons the corals incorporate δ 13C which reflects changes in δ 13C of atmospheric CO2; Sr/Ca and δ 18O in relative proportions inversely to the Sea Surface Temperature (SST), and the oxygen isotope also shows proportional correlation with salinity (SSS). The Rocas Atoll Biological Reserve, in the South Atlantic, is an ecological sanctuary of extreme importance for the conservation of marine life, and is located in an area of influence the principal oceanic-atmospheric systems responsible for the climate variability of Northeast Brazil, the Intertropical Convergence Zone (ITCZ), and the influence of Interhemispheric Thermal Gradient, and El Niño – Southern Oscillation. Information on the behavior of the precipitation regime and variability in SST over the atoll is scarce. Here a study on climate variability in atoll is described for the period 1958- 2013, using data from ERSST v5 (NOAA), and Precipitation (ERA-5 – ECMWF) for the period 1979-2013, in addition to Oceanic Niño Index - ONI and Atlantic Meridional Mode Index - AMM (PSL/NOAA). In this paper, a colony of Siderastrea stellata coral from Rocas Atoll, was dated by U-Th series, and provides 55-year records of Sr/Ca data, δ 18O and δ 13C. Cyclical variations of the coral data were confronted with the reconstructed instrumental data, and reveal the species' ability to respond to environmental changes. A decadal signal was observed in the three geochemical series, and mainly reflects TSM variations induced by oceanic variability modes and associated atmospheric systems.

BANKING MEMBERS:
Presidente - 1858120 - DAVID MENDES
Interno - 1164414 - WEBER ANDRADE GONCALVES
Externa ao Programa - 1378974 - LIANA DE FIGUEIREDO MENDES
Externo ao Programa - 2276514 - MARCIO MACHADO CINTRA
Externo à Instituição - NATAN SILVA PEREIRA - UNEB