 As a member of the "Deutschen Akademie der Wisschaften zu Berlin", (German Academy of Sciences Berlin), or DAW, Ertel founded and led the "Institute for Physical Hydrography" of this academy as of 1948.In 1949, Ertel was elected to be a full member of the DAW and was its vice president from 1951 to 1961.During this time, he saw to the founding of some new academy institutes, and also ensured that all of Germany could participate during the International Geophysical Years (1957/58 and 1958/59).