The seasonal changes of sea-level anomalies on the Persian Gulf (1993-2017)

In this study, sea level anomaly of Persian Gulf (spatial resolution of 0.25 degrees of latitudes and longitudes) was investigated in the MATLAB software environment by using long-term AVISO data for 25 years (1 January 1993 to 31 December 2017). The 25-year average of the data shows that the sea level anomaly is positive and equals 3.06 ± 0.05 cm (mean± standard deviation), which is higher than the global average. Its range varies from a minimum of 2.46 cm to a maximum of 3.42 cm. The 25-year average of each season illustrates that sea level anomalies face a rise in autumn and a fall in spring. The two seasons of summer and winter are transition seasons from the maximum anomaly of autumn to the minimum anomaly of spring. The results also show that the spatial distribution of sea level anomaly in the basin is different. The mean sea level anomaly trend in the Persian Gulf is +2.9±0.1 mm/year, which practically divides Persian Gulf in the three parts of northwestern parts near the Arabian coast (anomalies less than 2.5 mm/year), the northern and central parts of the gulf (anomalies of 2.5-5.5 mm/year) and the southern part of the gulf and Strait of Hormuz (anomalies more than 3.5 mm/year). Therefore, although the head of Persian Gulf has positive trend changes, it is less than its southern part and near the Strait of Hormuz. If the Persian Gulf Sea level continues to rise, over the next 200 years, the Persian Gulf sea level will rise more than 0.5 m, with significant changes in the size and area of the basin.