Enhancing projections of sea-level rise with changing seasonality for the Northwest European Shelf for 2023 to 2053.

Abstract

Sea-level rise is a primary damaging aspect of climate change, with potentially major consequences for coastal communities globally. In response to this, there has been a significant research effort into past and present patterns of sea-level change over multiple temporal and spatial scales to inform projections of future sea-level rise. While numerous studies have concentrated on global sea-level projections, there is a demand for more focused projections at the regional level. Existing work that seeks to project regional sea-level change has typically been limited by the complexity of regional climatic and atmospheric processes, and the difficulty of resolving these processes at relevant spatial scales within climate models. Finding alternative methods to resolve components at small enough temporal and spatial scales is therefore relevant to furthering our ability to project regional sea-level change. In this thesis, an approach is proposed and carried out to make projections of sea-level change for the Northwest European Shelf (NWES) between 2023-2053 at seasonal time steps and quantify the uncertainties related to each component of the projection. A novel aspect of the approach is the use of observed atmospheric-oceanic relationships to quantify the seasonal component of sea-level change, which, for the NWES, is strongly related to the North Atlantic Oscillation. Projections were made for 11 tide gauge locations across the NWES. Results show a set of robust projections that predict seasonal amplitudes between ± 0.1 m to ± 0.4 m. Across the 11 sites, projections are in line with SLC from observed sea-level data and existing projections of dynamic sea-level change. The uncertainties on the projections reflect uncertainty associated with the data used, assumptions within the methodology, and inherent variability present in the climate system. Overall, the approach demonstrated in the study is a novel way of projecting sea-level change over fine temporal and spatial scales.