Applying Empirical Orthogonal Function and Determination Coefficient Methods for Determining Major Contributing Factors of Satellite Sea Level Anomalies Variability in the Arabian Gulf

Abstract

Gridded satellite altimetry data of the Arabian Gulf during 1993–2017 were utilized to determine the relative contributions of sea surface temperature, sea level pressure, wind speed, and evaporation reanalysis data on the variability of remotely sensed sea level anomaly (SLA), which shows a mean increasing trend of 3 mm/yr. Sea surface temperature had the strongest effect on SLA, contributing 38.40% of the variability. Sea level pressure had the second greatest effect at 17%. Wind speed did not have a significant contribution to SLA variability, while evaporation had an effect of approximately 4.13%. EOF analysis was used to determine the mode of SLA variability. The first six modes explained more than 90% of the variability in SLA. The first mode, which represents the annual signal, explains 80.30% of the variability, while the second mode resolves approximately 6.80%. The contributions of different factors on the first and second modes show that the sea surface temperature and sea level pressure dominate the influence on the annual signal. Wind speed did not show a strong effect on either annual or semiannual fluctuations, while the main contribution on the semiannual signal was due to evaporation with 9.62%.