How well do multi-satellite products capture the space-time dynamics of precipitation? Part I: five products assessed via a wavenumber-frequency decomposition

Abstract As more global satellite-derived precipitation products become available, it is imperative to evaluate them carefully for providing guidance as how well space-time features are captured use in hydrologic modeling, climate studies and other applications. Here we propose a Fourier spectral analysis define suite of metrics which the spatial organization storm systems, propagation speed direction features, scales at satellite product reproduces variability reference “ground-truth” (“effective resolution”). We demonstrate methodology relates our physical intuition using case study system with rich structure. then five high-resolution multi-satellite (CMORPH, GSMaP, IMERG-early, IMERG-final PERSIANN-CCS) over period two years southeastern US. All show generally consistent power density when compared ground gauge-radar dataset (GV-MRMS), revealing agreement terms average morphology dynamics systems. However, deficit wavelengths shorter than 200 km periods 4 h reveals that all excessively “smooth”. The also low levels coherence these fine scales, discrepancies capturing location timing features. From coherence, shows superior ability resolving down products.