Astronomical and greenhouse gas configuration from past to future simulation: An analysis of sea surface temperature's impact on sea levels in Indonesia

• The study improves CCSM4′s climate component processes modeling. • CCSM4 enhances accuracy of global phenomena and regional climate variability simulations. • The model validation ensures the reliability for future climate projection studies. • CCSM4 aids climate assessments via insights into anthropogenic climate change. • The world’s largest archipelago in tropics, vulnerable to sea level rise disasters. Climate change and steric variables influence sea level rise in the modern era. This study used the Community Climate System Model version 4 (CCSM4) to compare sea surface temperature (SST) and sea level height (SSH) in Indonesia during the mid-Holocene (MH), pre-industrial (PI), and future periods in 2300 with Representative Concentration Pathways 8.5 (RCP8.5). The results show that the average SST value is lower in the MH, with a change in values of around −1°C in the MAM season and increases in the future by around 2°C, whereas the average SSH value is lower in the MH with a change in values of around −0.1 m during the SON season in Western Sumatra and increases in the future over the SON season by around 0.1 m in Northern Papua, compared to PI. The average correlation between the two metrics is positive, with values of 0.55 (MH-PI) and 0.8 (RCP8.5-PI). SST and SSH climatological patterns in Western Sumatra, the Banda Sea, and Northern Papua reveal that SST and SSH fall during the JJA season and increase during the SON season, respectively. This fluctuation is produced by either a lag in insolation or the winter remnant effect. Signal analysis with Fourier transform reveals that the major signal spectrum for changes in SST and SSH is contributed by annual and semi-annual periodicity in the three regions. A notable interannual periodicity exists; however, it is not predominant, leading to variable interannual influences on SST and SSH in Indonesia.