Regional sea level changes in the marginal seas of southeast Asia: Mechanisms and projections of possible 21st-century trends (IndoArchipel-2)
The main element of the project’s work plan is a programme of numerical experimentation consisting of the following sets of simulations:
(i) Regionally-refined simulations utilizing the model configuration with the 1/20°-nest, addressing the question of how the interaction of changes in the deep ocean with the complex bathymetry and the local forcing conspire in the generation of sea level patterns in the shallow seas and shelves of the study area. To which degree are the local sea level changes governed by the large-scale atmospheric forcing and reflect the basin-scale variability modes? To what extent are the deep ocean signals modified by interactions with the bathymetry, what is the effect of changes in the boundary currents for the local current dynamics and associated sea level patterns in marginal seas and passages of the Archipelago? How does the bathymetric influence change at longer time scales, and could thus be affected by future trends in the vertical density structure due to a progressing deep ocean warming?
(ii) A series of experiments with perturbations in the density structure of the Southern Ocean and the Pacific to alter the transport rates of deep water and the upwelling of those water masses in the Pacific will be aimed at isolating the forcing factors behind possible future trends of the ITF transport.
(ii) The high-resolution nested model configuration will be utilized in ‘projection’-experiments directed at delineating the possible future trends of regional sea level as a consequence of specific changes in the atmospheric forcing during the next 50-100 years. The main purpose of the high-resolution model is here to determine a regionally much more refined projection of sea level trends than in the original climate model projections which, owing to their coarse resolution, do not resolve the complex geography nor the current-bathymetry interactions potentially important in the area.