Recommendations on Which ACE Data to Avoid in Comparisons

Caveat Emptor - Not All Data Sets are Created Equal

For purposes of the ACE Validation Program, the ACE measurement data set starts on February 21, 2004.

This date marks the end of the Satellite Commissioning phase and the beginning of the Science Operations phase. There were some occultation measurements taken prior to this date but these should be avoided. Occultations prior to January 10 were for calibration and these occultations should not be used at all. Measurements taken during the Science Commissioning, during January and most of February, generally should not be used. Since February 21, 2004, there have been a few instances where there were issues with the data and the occultations from these periods should be avoided or used with caution. For example, detector temperatures which are higher than nominal degrade the SNR performance of the ACE-FTS and this can negatively impact the retrievals.

***Please note that there is a known issue affecting ~80-90 version 3.5/3.6 occultations per year, with anomalously high N2O measurements. As of January 30, 2018, we are working to add the affected occultations to the linked table below.***

The ACE Data Issues Page lists occultations with known issues. This list is updated as new issues are reported so please check it frequently. You can download a csv version of this using the button at the bottom of the page.

If you find any problems or issues with the ACE data please let the Validation Coordinator know by submitting a Data Issue Report.