Green wave
Original uploader was <a href="https://de.wikipedia.org/wiki/User:Honina" class="extiw" title="de:User:Honina">Honina</a> at <a class="external text" href="https://de.wikipedia.org">de.wikipedia</a>
CC BY-SA 3.0
Originally from <a class="external text" href="https://de.wikipedia.org">de.wikipedia</a>; description page is/was <a class="external text" href="https://de.wikipedia.org/w/index.php?title=Image%3AGr%C3%BCne_welle_2.PNG">here</a>.