Skip to content

Weekly periodicities of Aerosol Optical Thickness over Central Europe – evidence of an anthropogenic direct aerosol effect

by D Bäumer, R Rinke, B Vogel
Atmos. Chem. Phys. Atmospheric Chemistry and Physics ()
Get full text at journal


Statistical analyses of data from ground-based sun photometer stations in Central Europe are presented. All sta-tions are part of the Aerosol Robotic Network (AERONET), and only data of the highest data quality level 2.0 has been applied. The averages by weekday of Aerosol Optical Thick-ness (AOT) at a wavelength of 440 nm of 12 of the 14 stations in the investigation area show a weekly periodicity with low-est values on Sunday and Monday, but greatest values from Wednesday until Saturday, that is significant at least on a 90% level. The stations in Germany and in Greater Paris show weekly cycles with ranges of about 20% on average. In Northern Italy and Switzerland this range is about 10% on average. By applying several checks, we exclude that the weekly cycles were caused by a maintenance effect or by different retrieval conditions as a consequence of a weekly cycle in cloud cover. The corresponding weekly cycle of an-thropogenic gaseous and particulate emissions leads us to the conclusion of the anthropogenic origin of the weekly AOT cycle. Since these AOT patterns are derived from the reduc-tion of the direct sun radiation by the columnar atmospheric aerosol, this result represents strong evidence for an anthro-pogenic direct aerosol effect on shortwave radiation. Further-more, this study makes a first contribution to the understand-ing and explanation of recently observed weekly periodicities in meteorological variables as temperature in Germany.

Cite this document (BETA)

Readership Statistics

33 Readers on Mendeley
by Discipline
61% Earth and Planetary Sciences
24% Environmental Science
9% Physics and Astronomy
by Academic Status
27% Student > Ph. D. Student
21% Professor > Associate Professor
18% Researcher
by Country
6% Germany
3% Spain
3% India

Sign up today - FREE

Mendeley saves you time finding and organizing research. Learn more

  • All your research in one place
  • Add and import papers easily
  • Access it anywhere, anytime

Start using Mendeley in seconds!

Sign up & Download

Already have an account? Sign in