Dobson-stations performance assessment using TOMS data

Examples of comparisons of monthly summaries (based on daily measurements) of some of the regularily operating Dobson stations, with the values deduced from the Total Ozone Mapping Spectrometer (TOMS) overpass are given. Shortcomings in certain Dobson stations are identified, such as: use of an incorrect value for the extraterrestrial constant (HOBART); sudden large volume changes (Brisbane); unusually low Dobson readings (Mauna Loa); and use of inaccurate cloud blue sky charts, causing fictitious differences with direct sun measurements (Toronto).