The effect of Indian Ocean Dipole on precipitation in western Philippines recorded in stalagmite oxygen isotopes

Abstract

We investigated d18O values of duplicated stalagmites collected in Negros occidental, western Philippines. 22 and 16 layers of the stalagmites were dated by Th-230 method, and show the time sequence from 650 years BP to present. Our d18O records show a symmetric pattern to Indian records. This is probably due to IOD mode, which develops symmetric SST and precipitation structures between eastern and western coasts of Indian Ocean. The symmetric pattern between two d18O records is developed during the periods of anomalously high SST in western Pacific, suggesting that the increasing SST may accelerate the occurrence of IOD.