Diagram statistically displaying model performance for tides or quasi-periodic oscillations

Abstract

This paper presents a diagrammatic way to compare the amplitude and phase lag between observed and simulated by plotting the harmonic constants of tides in a polar graph that simultaneously shows two statistics, root mean square difference (RMSD) and correlation coefficient. The diagram can be used to display the improvement or progress of a model in terms of the RMSD as well as the amplitude and phase of the tides. The diagram can also provide an assessment of model performance with respect to amplitudes, phase lags, and RMSDs when there are many harmonic constants with widely ranging amplitudes and/or with different units of observations by displaying the ratio of the model values to the observed. For Quasi-periodic oscillations such as continental shelf waves, the diagram can provide the comparison and reveal the degree of the modulation in the amplitude and phase.