Resumo

MAGALLANES-QUINTANAR, Rafael; LOPEZ HERNANDEZ, Aurelio Manuel  e  GALVAN-TEJADA, Carlos Erick. Evaporation analysis and climate change in central México. Nova scientia [online]. 2017, vol.9, n.18, pp.76-93. ISSN 2007-0705.  https://doi.org/10.21640/ns.v9i18.750.

Long-term monthly pan evaporation time series registered at 35 meteorological stations located within Mexico’s state of Zacatecas were analyzed through linear regression approach in order to identify their trends and to calculate their anomalies. In addition, we analyzed the power spectrum signals of evaporation anomaly series through fractal analysis to identify their important frequencies and its possible connection with periodic phenomena. Results suggest that negative trends are prevailing over positive trends. We found negative linear trend for 21 out of 35 pan evaporation time series. 18 out of 21 decreasing trends were significant at p<0.05. On the other hand, 14 out of 35 pan evaporation trends were positive but only 8 of them at significant level (p<0.05). Moreover, the noise in these monthly pan evaporation series tends to be persistent behavior. Additionally, we found that important frequencies in our study seem that could be related with the yearly cycle, quasi-biannual cycle, ‘El Niño Southern Oscillation’ phenomena and sunspot cycle.

Palavras-chave : linear trends; fractal dimensión; power spectrum density; ENSO; sunspot cycle.