Model Simulation of Storm Surge in the Northwestern South China Sea Under the Impact of Sea Level Rise: A Case Study of Super Typhoon Rammasun (2014)

Abstract

Because of global warming, the sea level is expected to continue to rise, possibly having a significant impact on the intensities and spatial distribution characteristics of coastal storm surges. In this study, we took super typhoon Rammasun (2014) as a case study and applied the SCHISM (Semi-implicit Cross-scale Hydroscience Integrated System Model) to simulate storm surge in the northwestern South China Sea under future sea level rise (SLR) scenarios. To improve the accuracy of storm surge hindcast, we used reconstructed wind field to drive the model in which ERA5 reanalysis data were superposed on the wind field calculated from the Holland parametric cyclone model. The results show that the storm surge hindcast was significantly improved by using this reconstructed wind forcing. 2-D and 3-D model hindcast capabilities were compared; the 3-D model reproduced the storm surge better. The regional sea level projections in 2050, 2100, 2200, and 2300 for RCP 4.5 scenarios (provided by the IPCC AR6 dataset) were superposed on the original water depth as the predicted sea levels, then those depths were used in models of storm surge in the study area under a typhoon identical to Rammasun. Model results demonstrate that storm surge peaks in most sea areas decrease nearly linearly with SLR, especially in regions of high surges.

Impact of Typhoon on Coastal Upwelling Off The Eastern Hainan Island: A Case Study of Typhoon Rammasun (2014)

“…In addition, a warm current coming from Beibu Gulf via Qiongzhou Strait flowed along the northern coast of the Island. Zhou et al (2022) found that the east-west water level gradients at the Strait are responsible for this warm current.…”

Explanations for the positive storm surges on the left side of landfall typhoons in China

“…In order to achieve an accurate simulation of storm surges, various factors need to be considered, such as the configuration of shoreline and bathymetry, the value of bottom friction coefficient, and most importantly, the precision of typhoon wind field (Zhou et al, 2022). For the numerical simulation and prediction of storm surges, there are many kinds of wind fields that can be used.…”

Study of Landfalling Typhoon Potential Maximum Gale Forecasting in South China

“…Landfalling TCs accompanied by strong winds, which can trigger storm surges and rainfall that can further aggravate heavy rainfall disasters, represent a disaster-causing factor that cannot be ignored [3]. Super Typhoon Rammasun (2014), which was the strongest typhoon ever recorded to make landfall in China [4,5], had characteristics of multiple landings, rapid intensification, and maintained intensity. The maximum wind speed near the TC center reached 72 m/s when it first made landfall in Wenchang, Hainan Province [6].…”