Applications of Harmonic Analysis in the Processing of Marine Environmental Data

Abstract Periodic signals in marine environmental elements are crucial for understanding oceanic processes. This study compares Fourier series analysis and harmonic analysis for extracting periodic components from marine time series. Fourier methods rely on harmonic frequencies, limiting accurate fitting of non-harmonic signals like tidal constituents. Harmonic analysis overcomes this by specifying target frequencies and using least-squares fitting. The key innovation lies in establishing a comparative framework that clarifies theoretical distinctions and quantitatively demonstrates harmonic analysis’s superiority using sea surface temperature and sea level data. Results show significantly lower fitting errors for non-harmonic components like M 2 and K 1 tides, providing methodological support for refined marine data processing.