@article {265,
	title = {Abrupt mid-Holocene onset of centennial-scale climate variability on the Peru-Chile Margin},
	journal = {Geophysical Research Letters},
	volume = {36},
	year = {2009},
	note = {id: 1890; 499OY Times Cited:0 Cited References Count:41Y},
	abstract = {Understanding the natural climate variations in the eastern tropical Pacific (ETP) is crucial for predicting the evolution of the El Nino-Southern Oscillation (ENSO). Here we present the first continuous, decadal-resolution Holocene climate record from the Peru-Chile Margin, near the epicenter of the modern ENSO system. Geochemical proxies allow us to reconstruct sea surface temperature, phytoplankton productivity, and thermocline ventilation, variables that are tightly correlated to ENSO events today. Despite the observation that the mean state of all three variables did not change over the past 10,000 years, our data reveal a dramatic increase in climate variability near 5 ka; represented by prolonged periods (50-200 yrs) of climate extremes, which are absent in the early Holocene. These centennial-scale oscillations do not show typical El Nino-La Nina correlations between proxies. We therefore posit that a significant fraction of super-ENSO variance may originate outside the tropics, through processes that ventilate the ETP subsurface waters. Citation: Chazen, C. R., M. A. Altabet, and T. D. Herbert (2009), Abrupt mid-Holocene onset of centennial-scale climate variability on the Peru-Chile Margin, Geophys. Res. Lett., 36, L18704, doi:10.1029/2009GL039749.},
	issn = {0094-8276},
	doi = {10.1029/2009gl039749},
	author = {Chazen, C. R. and Altabet, M. A. and Herbert, T. D.}
}
@article {253,
	title = {Subdecadally resolved paleoceanography of the Peru margin during the last two millennia},
	journal = {Geochemistry Geophysics Geosystems},
	volume = {9},
	year = {2008},
	note = {id: 780; 303SA Times Cited:7 Cited References Count:54Y},
	abstract = {Using multiproxy sediment core data from the El Nino-Southern Oscillation (ENSO)-sensitive Peru margin, subdecadally resolved (down to similar to 0.6 year) surface productivity and subsurface denitrification are reconstructed for the last similar to 2300 years. Scanning XRF generated major elemental data (Ti, Fe, Si) correlate well with discrete inductively coupled plasma-atomic emission spectometry (ICP-AES) analyses and together with X-radiography (core density) are used as productivity indices. As surface productivity in this marine region is strongly impacted by ENSO, higher (lower) periods of surface productivity are inferred to represent a persistent normal/La Nina (El Nino)-like state. Surface productivity and subsurface denitrification appear to have remained intimately coupled during this period due to direct stimulation of requisite subsurface suboxia and/or hydrographic restructuring. The late Holocene Peru margin is characterized by persistent moderate productivity and subsurface denitrification punctuated at centennial scale by shorter-duration periods of high production and intense denitrification. These centennial-scale events are likely analogous to modern observations of decadal-scale "regime shifts{\textquoteright}{\textquoteright} but of higher amplitude and provide a background history for future natural changes to this system. Solar (irradiance) variability is suggested to have influenced Peru productivity as evidenced in numerous high-resolution paleorecords from the northern hemisphere.},
	issn = {1525-2027},
	doi = {10.1029/2007gc001744},
	author = {Agnihotri, R. and Altabet, M. A. and Herbert, T. D. and Tierney, J. E.}
}
