A GRACE/GFO Empirical Low-Pass Filter to Extract the Mass Changes in Nicaragua

Among the Gravity Recovery and Climate Experiment (GRACE) GRACE Follow-on temporal gravity products, north–south stripe noise in spherical harmonic coefficient (SHC) products contaminates inversion of Earth’s mass field. In this study, SHC are adopted to estimate changes Nicaragua. To improve estimation, we propose an empirical low-pass filter suppress noise. After only using our filter, Nicaragua regional uncertainty diminishes from 123.26 mm 69.11 mm, mean signal-to-noise ratio all available months (2002–2021) improves 1.67 1.8. Subsequently, is employed basin terrestrial water storage (TWS) change end, TWS estimations compared with various observations such as mascon hydrological models, situ groundwater observation. The main conclusions follows: (1) wavelet coherent analysis, there a negative resonance between climate factor (El Nino–Southern Oscillation) period 2~4 years; (2) significant ~3.8-year periodic signal estimation contributed by aliasing error. Our work can provide new knowledge references for small areas.