Measuring global mean sea level changes with surface drifting buoys

TL;DR

This paper proposes using a global array of surface drifting buoys with GNSS to independently estimate global mean sea level changes and trends, potentially supplementing existing tide gauge and satellite data.

Contribution

It demonstrates that a standardized array of 1250 buoys with GNSS can estimate sea level trends with high accuracy, assuming vertical position measurements are feasible.

Findings

Decadal trend estimates with <0.3 mm/yr uncertainty

Requires GNSS vertical error of 1.6 m or less

Provides an independent method for sea level monitoring

Abstract

Combining ocean model data and in-situ Lagrangian data, I show that an array of surface drifting buoys tracked by a Global Navigation Satellite System (GNSS), such as the Global Drifter Program, could provide estimates of global mean sea level (GMSL) and its changes, including linear decadal trends. For a sustained array of 1250 globally distributed buoys with a standardized design, I demonstrate that GMSL decadal linear trend estimates with an uncertainty less than 0.3 mm yr$^{-1}$ could be achieved with GNSS daily random error of 1.6 m or less in the vertical direction. This demonstration assumes that controlled vertical position measurements could be acquired from drifting buoys, which is yet to be demonstrated. Development and implementation of such measurements could ultimately provide an independent and resilient observational system to infer natural and anthropogenic sea level changes, augmenting the on-going tide gauge and satellites records.