What is typically used to improve the accuracy of long-term sea-level change observations?

Using a well-defined fixed level or datum is crucial for improving the accuracy of long-term sea-level change observations. A fixed level or datum serves as a stable reference point from which sea level changes can be measured over time. This reference allows for consistent comparisons of sea level at different locations and times, taking into account factors such as tide variations, seasonal changes, and atmospheric influences.

By establishing a reliable baseline, researchers can more accurately interpret the data related to long-term trends in sea-level changes. This method helps to minimize errors in measurements, ensuring that the observed changes are reflective of actual trends rather than fluctuations caused by variables that might not be consistent over the long term.

While historical tide databases, satellite altitude measurements, and real-time ocean data feeds all provide valuable information for understanding sea-level dynamics, they may not provide the same level of stability and reference necessary for long-term observations as a well-defined fixed datum does. These other methods may supplement sea-level data collection, but they do not replace the foundational importance of a recognized reference level.