Contemporary monitoring of storm surge activity
Authors: Ji Tao , Li Guosheng 
Published: October 2019

There is growing interest in storm surge activity related to catastrophic events and their unintended consequences in terms of casualties and damage around the world and in increasing populations and issues along coastal areas in the context of global warming and rising sea levels. Accordingly, knowledge on storm surge monitoring has progressed significantly in recent years, and this review, focused on monitoring the spatial and temporal variability of storm surges, responds to the need for a synthesis. Three main components are presented in the review: (1) monitoring storm surges from the viewpoint of three effective approaches; (2) understanding the challenges faced by the three monitoring approaches to increase our awareness of monitoring storm surges; (3) identifying three research priorities and orientations to provide new ideas in future storm surge monitoring. From the perspective of monitoring approaches, recent progress was achieved with respect to tide gauges, satellite altimetry and numerical simulation. Storm surge events can nowadays be identified accurately, and the surge heights can be calculated based on long-term tide gauge observations. The changing frequency and intensity of storm surge activity, combined with statistical analysis and climatology, can be used to enable a better understanding of the possible regional or global long-term trends. Compared with tidal observation data, satellite altimetry has the advantage of providing offshore sea level information to an accuracy of 10 cm. In addition, satellite altimetry can provide more effective observations for studying storm surges, such as transient surge data of the deep ocean. Simultaneously, the study of storm surges via numerical simulation has been further developed, mainly reflected in the gradual improvement of simulation accuracy but also in the refinement of comprehensive factors affecting storm surge activity. However, from the above approaches, storm surge activity monitoring cannot fully reflect the spatial and temporal variability of storm surges, especially the spatial changes at a regional or global scale. In particular, compared to global storm surge, tide gauges and satellite altimeters are relatively sparse, and the spatial distribution is extremely uneven, which often seriously restricts the overall understanding of the spatial distribution features of storm surge activity. Numerical models can be used as a tool to overcome the above-mentioned shortcomings for storm surge monitoring, as they provide real-time spatiotemporal features of storm surge events. But long-term numerical hindcast of tides and surges requires an extremely high computational effort. Considering the shortcomings of the above approaches and the impact of climate change, there is no clear approach to remedy the framework for studying the spatial and temporal characteristics of global or regional storm surge activity at a climatic scale. Therefore, we show how new insights or techniques are useful for the monitoring of future crises. This work is especially important in planning efforts by policymakers, coastal managers, civil protection managers and the general public to adapt to climate change and rising sea levels.