Extension of Satellite Altimetry Jason-2 Sea Level Anomalies Towards the Red Sea Coast Using Polynomial Harmonic Techniques

ABSTRACT

Satellite altimetry data are facing big challenges near the coasts. These challenges arise due to the fundamental difficulties of correction and land contamination in the foot print, which result in rejection of these data near the coast. Several studies have been carried out to extend these data towards the coast. Over the Red Sea, altimetry data consist of gaps, which extend to about 30–50 km from the coast. Two methods are used for processing and extending Jason-2 satellite altimetry sea level anomalies (SLAs) towards the Red Sea coast; Fourier Series Model (FSM), and the polynomial sum of sine model (SSM). FSM model technique uses Fourier series and statistical analysis reflects strong relationship with both the observation and AVISO data, with strong and positive correlation. The second prediction technique, SSM model, depends on the polynomial sum of sine, and does not reflect any relationship with the observations and AVISO data close to the coast and the correlation coefficient (CC) is weak and negative. The FSM model output results in SLA data significantly better and more accurate than the SSM model output.

KEYWORDS:

• Polynomial harmonic techniques
• Red Sea coast
• satellite altimetry Jason-2
• sea level anomalies

Acknowledgements

The authors are deeply thankful to the data providers; the JPL Physical Oceanography Distribution Active Archive Center (PODAAC), the Archiving Validation and Interpretation of Satellite Oceanographic (AVISO) for providing Jason-2 data. This also extends to the Saudi Arabian GCS for providing hourly tide gauge data along the coast of the Red Sea. They are grateful for the High-Performance Computing center at King Abdulaziz University (http://hpc.kau.edu.sa) for giving us a chance to use their facilities during analyses of data. Our thanks are for King Abdulaziz University, Jeddah, Saudi Arabia and Hodeidah University, Yemen for making this research possible. They are deeply grateful to Prof. Fazal Ahmad for his many suggestions and to Dr. V M Aboobacker for reviewing the final draft of this manuscript.