Two ozone uv analyzers were used, a Dasibi 1008 AH and a TECO 49. The TECO 49 analyze was calibrated to a NIST traceable analyzer at NOAA-CMDL prior to the project. One minute averages of the output of each analyzer were recorded on the PMEL data system and plots were made of the raw data. A small portion of the data was deleted (consisting mostly of times that the inlet air was passed through a zero filter - usually when the relative wind was well behind the beam of the ship). After the raw data were cleaned, the Dasibi 1008 AH analyzer was calibrated to the TECO 49 record and 30-minute averages were created. The 30-minute average from each instrument was then averaged together to create the final data file. 30-minute intervals that had no clean ozone data are tagged with a value -999.
The PMEL radon instrument is a "dual flow loop, two filtered radon detector". The general features of the instrument are described in Whittlestone and Zahorowski, Baseline radon detectors for shipboard use: Development and deployment in the First Aerosol Characterization Experiment (ACE1), J. Geophys. Res., 103, 16,743-16,751, 1998. The instrument response is due to radon gas, not radon daughters (all of the existing radon daughters are filtered out before entering the decay/counting tank). The instrument registers the total number of decay counts per 30 minute interval on a filter arising from the decay of radon in the tank. The time given in the data file is the time of the start of the counting interval. As the volume of the decay/counting tank was 905 l and the sample flow rate into and out of the tank was typically 70 l/min, the response time of the radon instrument was about 13 minutes. The radon detector was standardized in Honolulu at the beginning of the cruise and in Yokosuka at the end of the cruise using radon emitted from a known source.
Data can be downloaded in ACF format by following the ASCII link, or in binary netCDF file format by following the netCDF link