Persistence of El Nino - Southern Oscillation and the Southern Atlantic Oscillation throughout the Cenozoic (2016)

Undergraduate: Tyler Smith

Faculty Advisor: Joel Hudley
Department: Geology

---

Observed oceanic dipole systems, such as El Ni¿¿o¿¿¿Southern Oscillation (ENSO) and the Southern Atlantic Oscillation (SAO), are globally important factors in today's climate dynamics, however their directly measured record is relatively short (~100 years, Smith, T.M et al., 2008; Reischmann, E et al, 2016)). Bivalve, wood, and algal mat proxies have been used to indicate a similar thermohaline gradient and periodicity of ENSO and SAO teleconnections/oceanic dipole systems in Cenozoic and modern climates (Ivaney et al., 2011; Lenz et al., 2009). However, other studies suggest that the modern dipole systems are neither stable nor undeviating throughout the Cenozoic (Wara et al., 2005). In order to determine the duration and strength of the thermohaline gradient for which these two dipole systems have persisted throughout the Cenozoic time period, modern analog technique (MAT) methods, stable isotopic methods, and spectral analyses on Cenozoic sediment cores from online data repositories were used. The presence, abundance or absence of specific planktonic foraminifera in the sediment cores provided support for a thermohaline gradient of ENSO and SAO systems during the Cenozoic for comparison with the thermohaline gradient of the modern day dipole systems in order to determine correlation.