STUDY OF SEA SURFACE TEMPERATURE VARIABILITY IN PANJANG ISLAND, BANTEN: SATELITE, MODEL, PROXY, AND IN SITU DATA

• Main Author: Kartadimaja, Zulfikar
• Format: Final Project
• Language: Indonesia
• Subjects: Geologi, hidrologi & meteorologi
• Online Access: https://digilib.itb.ac.id/gdl/view/75721
• Institution: Institut Teknologi Bandung

Sea Surface Temperature (SST) is an important parameter in studying climate change and can indicate ocean-atmosphere interaction anomalies such as EI Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD). Due to limitation of in situ data in understanding the climate, data from satellite observations, model results, or proxy data are mostly used. The objectives of this final project are to evaluate SST relative to in situ from satellite observations, model results and coral Sr/Ca content as an SST proxy, to understand the variability and trend of SST in Panjang Island, Banten over the past 41 years (1981-2022), and calculate linear growth from Porites sp. coral samples and the influence of SST on the coral linear growth. Evaluation on SST from satellite observations (Optimum Interpolation Sea Surface Temperature V2.1), and models (Hycom Global Ocean Forecasting System V3.0 and V3.1) shows representative result on the satellite observation data relative to in situ (r = 0,853; n = 299) than model data, through descriptive statistics for satellites (???? ????????????????? = 0,445°C; ???? ???????????????? = 0,304°C; RMSE = 0,538°C). Testing the variance of satellite observation (model) data relative to in situ with p-value = 0,785 (0,346), exhibits no significant difference, but the average test for both (p-value < 0.001) experiences a significant difference. Equation of y= 0,953 x (SPL satellite) + 1,778 shows a linear relationship between SST in situ and SST satellite and it is used to reconstruct SPL in situ (???????? ???? ???????????? ???????????? ???????????? ????????? ). Coral powder sub-sampling was carried out with a 0.8mm drill bit then it is analyzed by using ICP-EOS to obtain the content of Sr/Ca. Chronological development of Sr/Ca based on SST reconstruction (in-situ x satellite) using the anchor point method. The linear regression equation for corals PN (PE) is Sr/Ca = -0,06 x ???????? ???? ???????????? ???????????? ???????????? ????????? + 10,729; r = 0,333; n = 150; p-value < 0,001 (Sr/Ca= -0,041 x ???????? ???? ???????????? ???????????? ???????????? ????????? + 10,073; r = 0,387; n = 48; p-value < 0,001). Verification results of SST (Sr/Ca-SPL) reconstruction of PN (PE) corals relative to in situ data has a difference of 0,001 – 1,201°C; r = 0,72; p-value < 0,001 (0,044 – 1,504°C; r = 0,708; p-value = 0,007) and the Sr/Ca content of corals represented SST variations in Panjang Island. The SST trend in Panjang Island, Banten shows an increase of SST since the last 41 years (1981 – 2022) of 0,012°C/year with SST in situ monthly variation up to 27,902 – 30,677°C. The daily variation of SST based on in situ SST ranges from 27,820 – 31,167°C during the period 15 April 2022 – 7 February 2023. Monthly SST conditions in Panjang Island are influenced by wind speed (r= -0,397; n= 497; p-value<0.001) and rainfall (r = -0,117; n = 497; p-value = 0,009). Variations on monthly SST anomalies show the effect of ENSO (r = 0,483; n = 495; lag = 3 month; p-value < 0,001) and IOD (r = -0,36; n = 495; lag = 0 month; p-value < 0,001) in Panjang Island, Banten. Linear growth of corals Porites sp. calculated by densitometric method using CoralXDS software. The age of PN (PE) coral samples was 12 years from 2009–2021 (4 years; 2018–2021) retroactively from October 2021 (time of collecting coral), with an average PN (PE) linear growth of 0,964cm (0,569cm). The value of the correlation coefficient between the annual anomaly of SPL reconstruction in situ and the linear growth of PN coral (PE) is 0,457; n = 12; p-value = 0,136 (-0,895; n= 4; p-value = 0,105).