Tide Gauge and Satellite Altimetry integration for Storm Surge Prediction
Andrersen, Ole Baltazar1; Cheng, Yongcun1; Deng, Xiaoli2; Steward, Mark2; Idris, Nurul2; Gharineiat, Zahra2
1DTU Space, DENMARK; 2University of Newcastle, NSW, AUSTRALIA

Tide gauge and satellite altimetry has vastly different spatial and temporal sampling. However the data can be integrated to take advantage of the high temporal sampling of the tide gauges with the high spatial sampling of the satellite. Combining the data, we have tried to investigate both high frequency signals (surges) but also annual to decadal sea level signal using data from the past 20 years to investigate existence of ability to capture surge and sea level along the Northwest European and Australian coastlines. The comparison demonstrates the importance of optimal tide modeling using the response method as well as careful use of the dynamic atmosphere correction delivered by the MOG2D model. Data from TOPEX/POESEIDON+Jason1/2 (T/P+J1/2) altimetry tide gauges recorders around both European and Australia coasts general exhibit temporal correlation of more than 90% for nearly all tide gauge stations. We have selected several representative surge events on the two continents based on tide gauge recordings and investigated the capability of detecting these using satellite altimetry. On the European coast we find that when 2 or more satellites are available we capture more than 90% of the extreme sea level events. Finally we have investigated how satellite and tide gauge observations can best be combined. One method studied is a multivariate regression method and another is an optimum 3D interpolation method to integrate the detided sea level from T/P+J1/2 altimetry and tide gauge recorders. The performance of these models is demonstrated by examining the hindcast skill, which are greater than 90% around some tide gauge stations.