RECONSTRUCTION OF SEA SURFACE TEMPERATURE DATA BASED ON SR/CA CONTENT OF PORITES CORALS IN AMBON BAY

• Main Author: Corvianawatie, Corry
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/70368
• Institution: Institut Teknologi Bandung

Outer and inner part of Ambon Bay which separated by sill (depth 10m) has a unique oceanography dynamic. In this research dynamical of oceanography analyzed based on sea temperature (SST). The lack of continual and long time series data SST could limit the study. To overcome this problem coral Sr/Ca is used to reconstruct SST. In this research, Porites coral taken from coast of Galala City, Outer Ambon Bay (depth +3m) is used. Sub-sampling of coral sample on their growth axis using0.7mm drilling bit is done to get the coral powder sample in monthly resolution. Coral sub-sampling result in 80 coral powder samples. Coral Sr/Ca analyzed using ICP-OES. Anchor point method is used to develop the chronology of coral Sr/Ca from ERSST v3b dataset and result in the regression equation of Sr/Ca=-0.059xSST+10.32 with r--0.699 (n=95, p<0.05). Mean value of reconstructed SST is 28.85°C (n=95, a-1.19°C). Reconstructed SST is verified with the SST local measurement (in situ data). The data length of SST measurement is from May to November 2008. The verification result the SST difference of 1.2-2.5°C with the error of -0.05% so based on the proxy SST calibration and verification, it convince that coral Sr/Ca records SST variation in the Ambon Bay, thus SST can be reconstructed using coral Sr/Ca from Ambon Bay. The reconstructed SST data is then can be use for analyzing the oceanographic condition in Ambon Bay. The seasonal variation of reconstructed SST shows maximum SST in December (during northwest monsoon) and minimum SST (during southwest monsoon). We compare reconstructed SST with air temperature, wind speed, and long of sun radiation and result in correlation coefficient SST and air temperature is r= 0.711(n=95, p<0.05), SST and wind speed is r=-0,609 (n=95, p<0,05), SST and long of sun radiation is r-0.602 (n=40, p<0,05). This more convince us that the seasonal variation of SST in Ambon Bay could be affected by the long of sun radiation, air temperature, and wind speed. There is small correlation between ENSO and SST anomaly (mean seasonal remove) in Ambon Bay even for time lag 3 months r=-0.209 (n=95, p<0.05).