The monthly sea-level anomaly patterns on the Persian Gulf

Due to the unique features of Persian Gulf, it is important to evaluate sea level changes temporally and spatially. In this study, the Sea Level Anomalies of Persian Gulf were processed using the average daily data of 25 years (1993-2017) with spatial resolution of 0.25 degrees along latitude and longitude in the Matlab software, to achieve the average monthly sea level anomaly patterns of Persian Gulf. The results show that the sea level anomaly is as an irregular oscillatory wave and its trend is incremental and equal to 2.9±0.1 mm/year (mean ± SD), which is 1.2 mm/year more than the global average rate. Monthly changes indicate that the sea-level anomalies are rising in October, November, and December and falling in February, March, April, and May, and other months can be considered as transitory months. The minimum sea-level anomalies occur in May (-0.05±0.19 cm) and their peaks occur at six months later in November (9.30±0.21 cm). The monthly spatial distributions are also different in the basin. By comparing the spatial patterns of different months, a relative symmetry was found between January and July, June, and December, which can be likened to a double-polar anomaly.