Geophysical Research Letters

Impact of short period, non-tidal, temporal mass variability on GRACE gravity estimates



[1] Using orbital simulations of the Gravity Recovery and Climate Experiment (GRACE) spacecraft, we examined the effects on gravity recovery due to short period, non-tidal temporal mass variability in the atmosphere, ocean, and continental hydrology. We found that the magnitude of the aliasing error was strongly correlated with the power of the high-frequency variability of the models. Degree error relative to measurement error increased by a factor of ∼20 due to atmospheric aliasing (corresponding to geoid anomalies of approximately 1 mm at 500 km wavelengths), by a factor of ∼10 due to the ocean model, and by a factor of ∼3 due to the continental hydrology model. De-aliasing done with approximate models gave the greatest reduction in aliasing error for the mid-degrees and higher. For the atmosphere, the residual error was ∼1/5 times that of the aliasing error. A barotropic ocean model reduced the aliasing error due to a baroclinic model to nearly the level of measurement noise.