Lettau’s Contribution to the Obukhov Length Scale: A Scientific Historical Study

Abstract

Abstract It has been repeatedly assumed that Heinz Lettau found the Obukhov length in 1949 independently of Obukhov in 1946. However, it was not the characteristic length scale, the Obukhov length L , but the ratio of height and the Obukhov length ( z / L ), the Obukhov stability parameter, that he analyzed. Whether Lettau described the parameter z / L independently of Obukhov is investigated herein. Regardless of speculation about this, the significant contributions made by Lettau in the application of z / L merit this term being called the Obukhov–Lettau stability parameter in the future.