[A-OS19] Sea level rise under global warming and its impact on coastal areas

[AOS19-01] Projected sea level changes around Japan from dynamical downscaling using a high-resolution ocean model

*Tatsuo Suzuki¹, Yoko Yamagami¹, Hiroaki Tatebe¹ (1.Japan Agency for Marine-Earth Science and Technology)

Keywords:dynamic sea level change, dynamical downscaling, global warming

Sea level rise is one of the most important issues of global warming on human society, with direct implications for coastal areas due to increased erosion and more frequent storm surge flooding. Furthermore, changes in dynamic sea level, reflecting changes in the surface current field of the ocean, are closely related to the transport of heat and nutrients. Understanding the distribution of sea-level changes during global warming is therefore important for considering impact assessments during warming, and outputs from global climate models (GCMs) participating in CMIP6 play an important role in informing a variety of assessments of future climate change impacts, although many models are insufficient to address issues of concern to stakeholders, for example, due to lack of resolution. The ocean component of common climate models does not resolve eddies and does not reproduce detailed ocean structures such as the Kuroshio Extension front and subarctic front as climate fields. In this study, dynamic downscaling during warming was carried out using a high-resolution ocean model (COCO5 eddy-resolving version) to determine how the structure of these detailed current fields in the ocean changes during warming. A historical experiment was conducted using JRA55-do to reproduce the detailed ocean current fields around Japan. Future warming anomalies from MIROC6 were added to the boundary conditions to assess the effects of global warming. The results show two peaks of dynamic sea level changes, associated with the northward shift of the KE front and the subarctic front.