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Impact of short period, non‐tidal, temporal mass variability on GRACE gravity estimates
Author(s) -
Thompson P. F.,
Bettadpur S. V.,
Tapley B. D.
Publication year - 2004
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2003gl019285
Subject(s) - aliasing , environmental science , geodesy , climatology , geology , atmospheric sciences , undersampling , computer science , artificial intelligence
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.