Laguna Pallcacocha Sediment Color Intensity Data and ENSO Variability During the Holocene, WDC/Paleoclimatology

This data set represents a continuous lacustrine (lake) sedimentary
record of Holocene El Nino/Southern Oscillation (ENSO) variability
Laguna Pallcacocha, Southern Ecuadorian Andes, Ecuador.

From the abstract
("http://www.ngdc.noaa.gov/paleo/pubs/moy2002/moy2002.html"):
"Here we present a record of sedimentation in Laguna Pallcacocha,
southern Ecuador, which is strongly influenced by ENSO variability,
and covers the past 12,000 years continuously. We find that changes on
a timescale of 2???8 years, which we attribute to warm ENSO events,
become more frequent over the Holocene until about 1,200 years ago,
and then decline towards the present. Periods of relatively high and
low ENSO activity, alternating at a timescale of about 2,000 years,
are superimposed on this long-term trend. We attribute the long-term
trend to orbitally induced changes in insolation, and suggest internal
ENSO dynamics as a possible cause of the millennial
variability. However, the millennial oscillation will need to be
confirmed in other ENSO proxy records."

For additional details see:
Moy, C.M., G.O. Seltzer, D.T. Seltzer, and D.M. Anderson, 2002,
Variability of El Nino/Southern Oscillation activity at millennial
time scales during the Holocene epoch. Nature, V. 420:6912 pp
162-165, November 14, 2002.