Reference the seabed topographic depth observations based on the national mean dynamic topography model

Area of Science:

• Geodesy and Oceanography
• Marine Geophysics

Background:

• The traditional mean sea surface reference in Vietnam, using the Hon-Dau tide gauge, faces challenges due to regional non-equipotentiality.
• Accurate depth observations are crucial for maritime activities and coastal management in Vietnam.

Purpose of the Study:

• To introduce and validate the Vietnam national mean dynamic topography model (MDTVN22) for precise depth observations.
• To establish a robust methodology integrating tide gauge data with the MDTVN22 model.

Main Methods:

• Utilized the MDTVN22 model for depth observations across 3430 sites in Hai Phong and 813 sites in Quang Ninh.
• Integrated shore tide gauge data with the MDTVN22 model for enhanced precision.
• Conducted validation experiments in Hai Phong to compare measurement discrepancies.

Main Results:

• Identified a 5 to 6 mm difference between the mean sea surface and MDTVN22 references in the Gulf of Tonkin.
• Validation experiments showed a minimal discrepancy of ±0.006 m using the MDTVN22 model compared to the traditional method.
• The integrated methodology proved resilient and enhanced the precision of depth observations.

Conclusions:

• The MDTVN22 model offers improved accuracy for depth observations in Vietnam.
• Adopting the MDTVN22 model is significant for precise seabed topography assessment.
• The developed methodology enhances the scientific validity of depth measurements in the region.