Improving SST reconstructions from coral Sr/Ca records: multiple corals from Tahiti (French Polynesia)

Abstract

We reconstruct SST from coral Sr/Ca ratios measured at three coral cores taken from the lagoon of Tahiti (French Polynesia). Two coral cores were drilled from the same coral colony (one horizontally and one vertically), and a third core was drilled vertically from another coral growing at a different site. We evaluate several Sr/Ca records as proxies for regional SST variations: (1) the three single-core records from Tahiti, (2) an average Sr/Ca record computed from the two cores drilled from the same coral colony, (3) an average Sr/Ca record computed from all three Tahiti cores, and (4) an average Sr/Ca record computed from the three Tahiti cores and a fourth core taken from a different island (Rarotonga). On a monthly scale, the average Sr/Ca record including the four coral cores from Tahiti and Rarotonga shows the best correlation with regional SST. The variance of the SST reconstruction is very realistic and the residual SST is low. This suggests that reconstructing SST from average proxy records gives a better representation of regional SST variations. Of the three Tahiti cores, the one that was drilled horizontally shows the best correlation with grid-SST on an annual mean scale. All three Tahiti corals show much larger interannual SST variations than that indicated by grid-SST.

Reconstruction of Sea Surface Temperature Data based on the Sr/Ca of Porites Coral in Ambon Bay

“…After that, the solutions were ready to be analyzed by SST reconstruction was started by developing the time chronology of the coral Sr/Ca using the anchor point method. Previous studies have stated that Sr/Ca is inversely correlated to SST data [6][7][8][9]14]. Thus, anchor points are located at every minimum and maximum Sr/Ca (which represent the month of maximum SST and minimum SST respectively).…”

“…The huge coral resources in Indonesia can be used to solve this problem. Besides the function of coral as a habitat for marine biota, coral also serves as natural recording medium for environmental parameters such as sea surface temperature (SST) [6][7][8][9] and sea surface salinity (SSS) [10][11][12]. These parameters are recorded by corals in the form of geochemical proxy.…”

“…This means that with a 1-meter coral sample we can reconstruct environmental data until a hundred years ago [11]. One well-known geochemical proxy that records SST is the ratio of strontium to calcium (Sr/Ca) [7,14]. Figure 1.…”

Evaluation of the Use of Faas for Sr/Ca Concentration Analysis of Porites From Ambon Bay and Jukung Island Coral

“…Pengendapan Sr dan Ca dalam biogenik karbonat karang sangat dipengaruhi oleh suhu air laut (Weber, 1973). Rasio stronsium dibanding kalsium (Sr/Ca) dalam karang inilah yang banyak digunakan sebagai alat (proxy) untuk merekonstruksi suhu permukaan laut pada masa lampau (Cahyarini et al, 2008;Cahyarini et al, 2009;Chen et al, 2010;Sayani et al, 2011).…”

The Influence of ENSO/IOD on SST Signal in Kendari, Southeast Sulawesi Waters: 27-year-records of Sr/Ca from Porites corals

“…Sr/Ca content in corals has been demonstrated as a temperature proxy (e.g. Cahyarini et al, 2009;Linsley et al, 2000). Combination of living and fossil corals can provide I J O G long time series climate data extending hundreds or even thousands of years ago.…”