Remedy 3: Standardize AMF calculation methods and databases of a-priori information used in AMF calculations to improve the accuracy of the measured total column ozone

Primary gap remedy type: 
Proposed remedy description: 

Differences between AMFs can cause discernible discrepancies between the ozone data sets. For example, some NDACC UV-visible groups use their own individual DOAS settings and ozone AMFs calculated with different RTMs and sets of ozone, pressure and temperature profiles as input data, and with or without latitudinal and seasonal variations. The objective of the recommendations formulated by the NDACC UV-visible WG previously was thus to reduce these discrepancies through the use of standardized DOAS settings and ozone AMF look-up tables that account for the latitudinal and seasonal dependencies of the ozone vertical profile (see Hendrick et al., 2011).

The next step is to review, update and expand these existing tables further by initiating a targeted effort which also incorporates all relevant findings previously attained within projects such as NORS as well as investigations undertaken within GAIA-CLIM. Projects such as FRM4DOAS which are using centralised processing for the ozone data analysis also promote the use of more standardized AMF calculations and databases. With all this in mind, setting up a project to review and investigate the best routines and input variables for the AMF calculations, and to then recalculate and update the NDACC AMF LUTs to be used to homogenise the ozone total column data measured at different locations would be an efficient way forward.


Standardized AMFs will improve the overall accuracy of the measured total ozone column retrieved from zenith sky UV-visible measurements.

Measurable outcome of success: 

Determine the difference between standardized AMFs and individually calculated ones and, in turn, the difference in the calculated vertical ozone columns. If the standardized AMF lead to smaller uncertainties in the total column ozone datasets we know that the remedy was successful.

Expected viability for the outcome of success: 
  • Medium
Scale of work: 
  • Single institution
  • Consortium
Time bound to remedy: 
  • Less than 3 years
Indicative cost estimate (investment): 
  • Low cost (< 1 million)
Potential actors: 
  • EU H2020 funding
  • Copernicus funding
  • National funding agencies
  • ESA, EUMETSAT or other space agency
  • Academia, individual research institutes