Research Article

Possible Micrometeorological Anomalies Induced by Volcanic Activity Recorded at Stromboli Island (Aeolian Archipelago, Italy)

Figure 6

Power spectra obtained by FFT applied to the hourly atmospheric pressure ratios between Stromboli and Salina islands. (a) (brick red line, August 2011–February 2012) refers to the turbulent period embracing the 2011 volcanic unrest, compared to the equivalent quieter period of the next year (August 2012–February 2013, blue line in (b)). Data related to the eruptive period (August 2014–February 2015) are discontinuous, not allowing FFT analysis. Both curves start at 2 hours for removing aliased data determined by sampling period (1 hour).
(a)
(b)