However, author critiques this factor as "rather unrealistic". Second factor is temporal-spatial focusing which is the result of applying dispersion to a wave group with chirped spatial distribution of frequencies. Author notes that this mechanism can work for the "forced" wavetrains only which can not develop spontaneously. Finally, third factor is nonlinear focusing which produces solitons and so-called breathers as model representations of rogue waves. About real mechanisms of the rogue waves forming in the open ocean, author concludes that 'nobody knows the answer to these questions yet.'
My Comments: This paper shows that there are some fields for researches with no direct and clear answers. Real mechanism of the rogue waves forming in the open ocean is yet unknown. Existing mathematical models for explanation of these phenomena are refined but not realistic. Indeed, considered mechanisms for the wave energy focusing are operable only for narrow sets of cases or for unnatural conditions. Details of mathematical notations (especially in Appendix) were not clear for me.
Article Summary: This is short but comprehensive introduction to the freak/rogue waves phenomenon. It contains well adjusted set of facts and ideas about rogue waves, namely: informal definition, brief history of observations with examples, discussion about causes of its origin, typical values of the break forces, sea conditions that may create (or accompany) freak waves, etc. There are no formulae at all. This article serves as global pattern for the rogue waves problem whereas numerous articles concentrate upon mathematical details and minor features of this phenomenon.
My Comments: As for me, this is one of the best articles about rogue waves. Some facts are just amazing. For example, cases from the article show that freak waves greater than 25 meters in height are real and much more common than expected. Obviously, this phenomenon is far beyond so-called linear model. Than, actual causes and mechanisms of rogue waves are unknown (cf. previous article). Here, unpredictable freak waves are real miracles of the Nature, not mirages. It is important to distinguish freak waves and tsunamis. Then, article contains tremendous facts about the force of a breaking freak wave. It is about 100 MT/m2 for a 12-meter rogue wave which is much more than for wave in linear model. Article reading was easy and fascinating. Article is highly recommended for any scholar at the beginning stage of studying this phenomenon.
Source: Proceedings of Rogue Waves 2004 Conference, Brest, France - October 2004.
Off the Internet at: http://www.ifremer.fr/web-com/stw2004/rw/fullpapers/haver.pdf
Article Name: Freak waves: a suggested definition and possible consequences for marine structures.