Resolving mass flux at high spatial and temporal resolution using GRACE intersatellite measurements

• Published in: Geophysical research letters Vol. 32; no. 4; pp. L04310 - n/a
• Main Authors: Rowlands, D. D., Luthcke, S. B., Klosko, S. M., Lemoine, F. G. R., Chinn, D. S., McCarthy, J. J., Cox, C. M., Anderson, O. B.
• Format: Journal Article
• Language: English
• Published: American Geophysical Union 01-02-2005; Blackwell Publishing Ltd
• Subjects: Amazon Basin; Flux; Geodesy and Gravity; Geophysics; Geopotential theory and determination; GRACE (experiment); Hydrological cycles and budgets; Hydrology; Instruments and techniques; modeling; Monitors; River basins; Satellite geodesy; Spatial resolution; technical issues
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2004GL021908

The GRACE mission is designed to monitor mass flux on the Earth's surface at one month and high spatial resolution through the estimation of monthly gravity fields. Although this approach has been largely successful, information at submonthly time scales can be lost or even aliased through the estimation of static monthly parameters. Through an analysis of the GRACE data residuals, we show that the fundamental temporal and spatial resolution of the GRACE data is 10 days and 400 km. We present an approach similar in concept to altimetric methods that recovers submonthly mass flux at a high spatial resolution. Using 4° × 4° blocks at 10‐day intervals, we estimate the mass of surplus or deficit water over a 52° × 60° grid centered on the Amazon basin for July 2003. We demonstrate that the recovered signals are coherent and correlate well with the expected hydrological signal.