Fourier analysis and Wavelet applied to air temperature in different types of occupation

Temperature time-series are commonly used to study the climate and due to the temporal nature of their signals, require investigations based on time-frequency space in order to reveal the spectral characteristics as a function of time and the Wavelet transform provides an accurate representation of a signal as a function of time and frequency simultaneously, as well as, to analyse any signal, to which the Fourier series is limited to certain tests. Thus, this study made a descriptive analysis using the monthly series of Fourier and Wavelet transform of the variable air temperature at four points of the study, three urban and one rural area, for the year 2007. For the variable air temperature it was found that the energy intensity in the high frequency was 24 and significant powers over the whole year was verified, in time scales from 2 to 32 days for the four studied points, whose variance is more pronounced at the center of urban area.