Modeling of a Marine Geoid Along the Nigerian Coastal Waters

Abstract

The marine geoid is a consistent reference surface which is a crucial component in understanding ocean currents, sea level changes, and ocean atmosphere interactions. The use of inconsistent reference datum that can vary over time and area, can constitutes some forms of problems when generating charts at some required accuracies. Therefore, this research aimed to develop a marine geoid model along the Nigerian coastline, by using Sentinel-3 satellite altimetry data. The methodology employed in this research was a remote sensing approach, which used satellite altimetry approach to develop the marine geoid, which involves data collection, data extraction, data processing and data analysis of sentinel 3 satellite altimetry data to obtain the mean sea surface (MSS) and the mean dynamic topography (MDT) used to develop the marine geoid model. The analyses of MSS, MDT, and geoid data revealed that the MSS values along the Nigerian coastal waters are relatively high with moderate variability, while the MDT values exhibited more consistency, with minimal deviations and normally distributed. The marine geoid analysis showed significant spatial variability, with higher geoid heights in the southern and eastern parts of the coastline, and lower values in the north and west. The study reveals that the marine geoid values ranging from 9.8066 meters to 24.5928 meters, with a mean value of 16.86 meters. The statistical summary of MSS values shows a range from 10.255 meters to 25.012 meters, with a mean value of 17.3046 meters. The statistical summary indicates a relatively narrow range of MDT values, with a minimum of 0.4013 and a maximum of 0.4864, with mean value of 0. 4447.The results indicate that satellite altimetry missions, provide effective means of generating detailed marine geoid model, which are crucial for enhancing our understanding of sea level variability, ocean circulation, and gravity field variations. The findings also underscore the importance of continuous geodetic and oceanographic research in improving the accuracy of geoid models, which can provide information for coastal managements and contribute to insight of sea-level rise.