Since the present paper had gone to print, the author has had opportunity to study an important paper by Dr Mircea Herovanu: Determination des paramètres d‘Ångström par des observations actinométriques courantes (Geofisica pura e applicata, Vol. 44 1959/III). Evidently the method of Herovanu is fundamentally very similar to the one applied in the present paper, with the exception that Herovanu does not make the simplifying assumption that the two groups of radiation, corresponding to our λ1, and λ2, can be regarded as homogeneous. His computations then are more laborious and must be based on graphical integration. It can be shown however, that his results, with such an accuracy as the measurements are justifying, can be derived equally well, in applying equations perfectly similar to those given in the present paper. His investigation then furnishes a further support for the validity for practical work of the assumption as regards the the homogenety of the wavelength groups considered. I propose to considered this question more in detail in a following note.
Techniques of Determinig the Turbidity of the Atmosphere1
Article first published online: 18 MAR 2010
1961 Blackwell Munksgaard
Volume 13, Issue 2, pages 214–223, May 1961
How to Cite
ÅNGSTRÖM, A. (1961), Techniques of Determinig the Turbidity of the Atmosphere. Tellus, 13: 214–223. doi: 10.1111/j.2153-3490.1961.tb00078.x
- Issue published online: 18 MAR 2010
- Article first published online: 18 MAR 2010
- Manuscript received January 16, 1961
After a short survey I of the principles underlying the determination of the turbidity coefficient β, earlier introduced by the author as a measure of the atmospheric turbidity, a condensed summary II is given of earlier and also of more recent determinations of β. The variation of the turbidity with the time of the year, the airmass and with latitude is discussed. Finally a simple method of determining the wave length dependence of the extinction by atmospheric aerosol is outlined. The method is founded upon measurements of integral radiation values with aid of pyrheliometers and glass filters, III. Accuracy and probable error are considered, IV.