Abstract
The Indo‐Pacific coral Diploastrea heliopora reveals regional multidecadal‐ to centennial‐ scale climate variability using coral carbonate δ18O (δ18Oc) as a combined proxy for sea surface temperature (SST) and sea surface salinity (SSS). However, to assess the coral's full potential in resolving climatic events, an independent SST proxy would be more advantageous. We examined both Sr/Ca and δ18O of Diploastrea against an adjacent Porites lobata core collected from northeast Luzon, Philippines. Winter Sr/Ca data from Diploastrea show a significant correlation to SST (r = −0.41, p < 0.05, (root‐mean‐square="" of="" the="" residual)="" rmsr =" 0.81°C)" and="" provide="" a="" proxy="" with="" similar="" sensitivity="" as porites(r ="">< 0.05, rmsr =" 0.62°C)." an="" interspecies="" sst="" record="" is="" shown="" to="" be="" robust="" and="" used="" for="" a="" reconstruction="" of="" the="" pacific="" decadal="" oscillation="" during="" boreal="" winter="" (r =" −0.70, p = 0.02)." while="" we="" were="" unable="" to="" generate="" a="" robust diploastrea δ18o‐sss="" calibration="" at="" interannual="" timescale,="" the="" freshening="" trend="" toward="" the="" present,="" commonly="" observed="" in="" the="" region,="" is="" qualitatively="" captured="" in diploastrea δ18o.="" comparison="" with porites δ18o="" and="" instrumental="" sss="" records="" shows="" that="" the="" magnitude="" of="" freshening="" is="" consistent="" between="" coral="" species.="" wet="" and="" dry="" season porites δ18o="" provide="" support="" for="" the="" relative="" influence="" of="" el="" niño–southern="" oscillation="" events="" and="" local="" precipitation="" to="" sss="" variability="" at="" our="" site.="" the="" multiproxy,="" multispecies="" approach="" of="" this="" study="" further="" strengthens="" the="" evidence="" for diploastrea as="" an="" alternate="" climate="" archive="" in="" the="" indo‐pacific="" region="" and="" seals="" its="" potential="" in="" helping="" resolve="" less="" understood="" global‐scale="" climate="">