Research Interests
The tropical oceans of the world serve as the heat engine that drives global atmospheric circulation and influence climate phenomena such as El Niño and La Niña, which have global and societal impacts. In order to investigate how tropical oceans vary over time, climate records such as SST and SSS are needed to constrain tropical variations. In regions where no instrumental records are available, massive corals serve as proxy recorders of climate. Massive coral skeletons are composed of CaCO3 and have annual density bands, similar to tree-rings, and the coral skeletal geochemistry records variations in SST and SSS. Using geochemical analytical tools such as Stable Isotope Ratio Mass Spectrometry and Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES), variations in oxygen isotopes and trace elemental ratios (Sr/Ca) can be calibrate against instrumental records to reconstruct SST and SSS variations. Because massive corals are long-lived and fossil colonies are preserved in the geological record, Paleoclimatologists can reconstruct past climate on inter-annual to centennial time scales and address questions concerning ENSO, decadal variability, cooling during the Little Ice Age, and other climate phenomena.

My research uses an inter-disciplinary approach, combining geology with chemistry and biology to address questions concerning climate and testing their results against physical constraints of the ocean-atmosphere system. Current and past projects include:

• Replication study of coral Sr/Ca records from New Caledonia, SW Pacific Ocean, for the period 1900 to 1999;

• Reconstructing SST and SSS variations in the SW tropical Pacific over the past 350 years using coral geochemical records from New Caledonia;

• Investigating SST and SSS variations in the Tahiti, central tropical Pacific, during the Holocene

• Exploring multi-decadal to centennial scale climatic variations in paleoclimatology records using time series analysis.

Papers & Presentations

DeLong, K.L., Quinn, T.M., Taylor, F. 2005. Sea Surface Temperature Variability in the Southwest Tropical Pacific Since1679 AD Derived From Coral Skeletal Geochemistry. Poster 2005 AGU Fall Meeting. (PDF, 3.4MB)

DeLong, K.L., Quinn, T.M., Taylor, F. 2006. Reconstructing 20th Century SST Variability in the Southwest Pacific: A Replication Study Using Multiple Coral Sr/Ca Records from New Caledonia. Poster 2006 AGU Fall Meeting. (PDF, 2.0MB)

DeLong, K. L., Quinn, T. M. and Taylor, F. W., 2007, Reconstructing 20th Century SST Variability in the Southwest Pacific: A Replication Study Using Multiple Coral Sr/Ca Records from New Caledonia, Paleoceanography, 22, PA4212, doi:10.1029/2007PA001444. Email kdelong@marine.usf.edu for electronic password to download a copy from AGU.

DeLong, K.L., Quinn, T.M., Poore, R.Z., and Mitchum, G.T. 2007. Investigating the Forcing and Response in Proxy Records of Multi-Decadal Scale Climate Variability, Poster 2007 AGU Fall Meeting. (PDF, 2.3 MB)

DeLong, K. L., Quinn, T. M. and Taylor, F. W., 1st International Sclerochronology Conference, July 2007 “Reconstructing 20th Century SST Variability in the Southwest Pacific: A Replication Study Using Multiple Coral Sr/Ca Records from New Caledonia” Received Outstanding Student Presenter award.