Different methods exist to implemen

Different methods exist to implement spectral analysis from a discrete time record. The Fast Fourier Transform (FFT) is the common one as used in this study based on Nortek STORM software. First of all, one should recognize extreme events as the candidates of measured data (see Fig. 2) by defining a meaningful threshold. Here, wave height over 1 m is considered as an appropriate threshold to gather enough amount of wave records. Also, the data should be treated carefully considering anomalies, e.g.,gaps or spikes. Earlier analysis of over 24000 seventeen minutes long data series from August 2006 to September 2007 showed that some storms last for about 48 h. Here, it should be noted that the measurement tool is turned on every 1 h; working for seventeen minutes. After some basicdata assessment, more than 100 extreme events, most of them belonging to the Monsoon Season, were selected for the spectral analysis.