Photochemical Box Model Output for ACE Occultations

Photochemical corrections are necessary for making meaningful validation comparisons of diurnally varying species such as NO and NO2. The output of a photochemical box model can be used to accomplish this. It is done by calculating the VMR of the species of interest at the local time of each measurement and using these values as a scaling factor to map the measurement at local time 1 to local time 2.

To allow a consistent correction method to be used by the ACE Validation Team, Chris McLinden from Enivronment Canada has used his box model to calculate the VMR profile of nearly all of the ACE-FTS species for each occultation. He has also provided the VMR profiles for 6 species (NO, NO2, HNO3, N2O5, ClO and ClONO2) over the entire dirunal cycle at 33 time steps. These can be used to map measurements of one of these species from one local time to another. Nominally, the altitude range of these calculated profiles is 10 - 50 km with the lower altitude limited by the lowest alitude measured by the ACE-FTS instrument. These calculations are run using the ACE-FTS ozone, temperature and pressure profiles as inputs for each occultation.

A readme file has been provided by Chris. The data files are provided in ASCII format and as MatLab .mat files. Format descriptions are available for both the ASCII format files and the .mat files. Note: the .mat files are only compatible with MatLab version 7.0 or higher.

Use your ACE Validation username and password to access these files.

To access ASCII formatted files: ASCII files
To access MatLab .mat files: MATLAB files