Space-Time Analysis of the Sea Level Variability Of the Arabian Sea using Satellite Altimetry Data

The ongoing effects of climate change are contributing to a gradual rise in sea levels, which has become a significant environmental concern. It creates a serious threat to coastal areas, especially in the Gulf Region, which includes various cities bordering the Arabian Gulf, the Red and the Arabian Sea. This phenomenon has the potential to significantly influence the socioeconomics of the region by altering coastal marine ecosystems and can pose serious infrastructure sustainability challenges. This research focuses on analyzing the sea-level variability in the Arabian Sea using satellite altimetry data from 1993 to 2023. The analysis was conducted along a profile that runs along the coastline of the Arabian Sea, closer to the southeastern coastal areas of the Arabian Peninsula Region. To ensure stationarity, the satellite altimetry time series data (1993- 2023) was decomposed into seasonal and trend components. The seasonal components were modeled using the first-order Fourier Series. Along the profile, the results were presented at four points i.e., point 1 is located at the southern end of the Arabian Sea, while point 4 is located at the northern end of the profile (close to Oman Gulf). A variability in the seasonality model with maximum peak-to-peak amplitude (-13 cm to +10 cm) was observed at 3rd point toward the north, and as one moves towards the south the seasonal change gradually decreases with a minimum value at the last point located in the south (- 8.2 cm to 6.2 cm). Trend analysis was conducted using Mann-Kendall Test to assess its significance and was modeled using piecewise linear regression to quantify the oscillations in different epochs. The magnitude and direction of the trends at all selected locations vary at different time epochs, suggesting the role of climatic forcing that controls the sea level variability at the inter-annual scales. The results shows that the fastest sea level rise was after 2013 in point 4 closer to the confluence of the Arabian Sea and Oman Gulf, which is 1.17±011cm/year. In the other hand, the slowest rise was before 2010 in point 1 closer to the confluence of the Red Sea and the Arabian Sea with a rise of 0.49 mm/year. This is a baseline cost-effective study that uses freely available satellite data to understand sea level variability in the study area, underlining seasonal, inter-annual, and long-term variability and further help to observe the possible teleconnection between the Arabian Sea, Arabian Gulf, and the Red Sea.