
Dear Mark,
 
In the paper under proofreading stage, I have asked to change the following sentence on page 3 in the explanation of the Umkehr effect:
 
“As the solar zenith angle (90° < SZA < 60°) is decreasing, …” to “As the solar zenith angle (60° < SZA < 90°) is increasing, …” 
 
The confusion was introduced when I changed from “solar elevation angle” parameter to the more communally used “solar zenith angle” parameter which increases when the sun is setting in the evening.
 
Thank you for accepting this correction. 
 
Best regards,
 
René Stübi
 
Federal Department of Home Affairs FDHA
Federal Office of Meteorology and Climatology MeteoSwiss
