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The tides play a significant role in driving global oceanic mixing. While satellite altimetry provides accurate measurements of global tidal elevations, information about global tidal transports is limited. However, satellite magnetometer observations have allowed for the detection of magnetic signals induced by ocean tides. In this study, we demonstrate how satellite magnetometer observations can be used to directly derive global ocean tidal transports.

The movement of electrically conducting materials within Earth’s magnetic field generates an electromagnetic field through induction. This phenomenon occurs with oceanic currents and tidal motions. Previous studies have successfully detected tidal magnetic signatures using satellite data, and the number of resolved constituents continues to grow. These tidal signals can provide valuable information about the spatial distribution of conducting materials in the Earth’s mantle.

Estimating oceanic properties, such as ocean transports, temperature, salinity, and electric conductivity, using electromagnetic signals is desirable. However, existing studies rely heavily on numerical ocean models or limited local measurements, resulting in high uncertainties. Recently, global satellite electromagnetic fields have been used to estimate temporal variations of the global oceanic heat content.

Satellite magnetometers are also crucial for estimating tidal currents in other celestial bodies. Liquid salty oceans on icy moons, such as those around Jupiter and Saturn, could be detected and their properties estimated through electromagnetic induction processes.

To derive tidal transports from satellite magnetometer observations, we combine the Kalman Filter algorithm and the x3dg electromagnetic induction solver. The Kalman Filter algorithm is a sequential assimilation algorithm that involves a forecast and an analysis step. The x3dg solver allows for accurate estimation of the magnetic response to an inducing field. By assimilating satellite data, tidal transports can be recovered without relying on specific oceanographic forward models or prior estimates of oceanic friction.

In conclusion, satellite magnetometer observations offer a valuable method for directly deriving global ocean tidal transports. This information is crucial for better understanding oceanic mixing and can also have implications for the exploration of other celestial bodies with liquid oceans.

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