The data are available the day after they are produced by the Met Office.
Software is also available to calculate potential vorticity on the same grid.
The data assimilation system is a development of the scheme used at the Met Office for operational weather forecasting, which has been extended to cover the stratosphere. For short periods of particular interest the analyses are available at 6-hourly intervals. Assimilation experiments using UARS data in addition to operational meteorological observations have been carried out for limited periods. The BADC has also produced a set of monthly mean and zonal mean data. Software is available from the BADC to help you to read and analyse the data and to calculate Potential Vorticity.