Statistical significance of a weak spectral peak using filtering techniques: a case study

Abstract

Se aplican técnicas de filtrado a series de geopotencial en los niveles de 850, 700 y 300 hPa de Howard Base, Panamá para determinar si un pico espectral débil cerca de la frecuencia de 0.25/día puede ser considerado real o no. Los filtros aplicados a los datos son un filtro pasa-banda ARMA y un filtro para cancelar polos. Los ensayos estadísticos utilizados son aquellos apropiados a series filtradas y no respaldan la hipótesis que el pico es real.Filtering techniques are applied to geopotential series at the 850, 700 and 300 hPa levels at Howard Base, Panama to determine if the weak spectral peak near a frequency of 0.25/day can be considered real or not. An ARMA bandpass filter and a pole cancelling method are applied to the data. Statistical tests suitable to filtered series are applied and it is determined that the hypothesis that the peaks are real is not supported.