Coral Records of 20^th Century Tropical Pacific Climate

           I am interested to investigate how the tropical Pacific climate might evolve under the current anthropogenic warming. A better understanding of this issue is critical considering significant and widespread influence of this climate system on global temperature and precipitation. My approach is to reconstruct 20^th century tropical Pacific climate using continuous and high resolved climate proxies derived from coral geochemistry.  Currently, I study corals from three islands of the northern Line Islands chain located the central tropical Pacific (Palmyra, Fanning and Christmas Islands; 2N-6N, 157W-162W)  to reconstruct the histories of sea-surface temperature (SST), salinity and upwelling  over the last century.  I am planning to expand the coral collection to southern Line Islands in the near future. 

Location of study sites with climatological SST of the tropical Pacific

           In order to reconstruct SST and salinity, I measure coral Sr/Ca ratios as a proxy for SST and coral d¹⁸O values as a proxy for SST and salinity.  Then, I reconstruct the history of salinity using the values of d¹⁸O of seawater, which is derived by subtracting the SST contribution on coral d¹⁸O values.  For my upwelling proxies, I intend to use coral Cd/Ca and Ba/Ca ratios.  The prospect of using these upwelling proxies on my corals is still under investigation.  I received an introductory training for measuring these proxies from Dr. Katie Matthews (a former PhD student of Dr. Andrea Grottoli at UPenn) and Dr. Bill McDonough (Univ. of Maryland-College Park).   

           Currently, I am working on the late 20^th century section (post-1970) of SST and salinity reconstructions from the three islands, and trying to manuscript the results.

           On my personal note, I am deeply interested to see the finding on which direction the tropical Pacific climate is evolving under the current state of warming.  What is going to happen with the tropical Pacific climate?  The answer will greatly influence the surrounding countries including mine.  I was so fascinated by the strength of the 1997-98 ENSO (El Nino/Southern Oscillation); the drought and the hotspots on our tropical forests during El Nino, and then the floods that submerged the first floor of my school when La Nina hit.  I had never seen anything like that, and strangely had never heard the term ENSO (well, I was just born when the previous big ENSO hit).  The big El Nino and La Nina were a double-punch mess that unfortunately could not come at any better political and economic situations.  I find it helpful to keep in mind the ultimate goal of what I am working on, to keep me motivated when lab works become very very repetitive ;)

Last updated: Fall 2008.