Radio atmospheric Sferics received from about distance or greater have their frequencies slightly offset in time, producing "tweeks". When the electromagnetic energy from a sferic escapes the Earth-ionosphere waveguide and enters the magnetosphere, it becomes dispersed by the near-Earth plasma, forming a whistler signal. Because the source of the whistler is an impulse (i.e., the sferic), a whistler may be interpreted as the impulse response of the magnetosphere (for the conditions at that particular instant). A lightning channel with all its branches and its electric currents behaves like a huge antenna system from which electromagnetic waves of all frequencies are radiated. Beyond
Rough Waves Shukei (), whose still-extant paintings include a number of dynamic and mysterious images of sea waves, among them "Egret, Moon, and Wave" and "The Wind and the Waves". "Rough Waves" also reflects the influence of Tawaraya Sōtatsu, who specialized in gloomy landscapes, but is nevertheless an independent interpretation by Ogata of the frightening and violent force of the sea. "Rough Waves" impressed Ogata’s follower Sakai Hōitsu, who in 1805 created his work "Waves", in which he tried to convey a similar frightening atmosphere and a premonition of danger. At some time in the past, Hōitsu's family had commissioned work from