The ozone device was operated in the crow's nest to be free of ship interference. This precautionary measure proved to be unnecessary, as parallel measurements with an optical ozone device showed. It even had disadvantages because of the awkward usability and was no longer practiced on later trips. The bubbler was completely replaced once during the trip. The air pump on the ozone device was changed five times as a precaution. The care was provided by Dr. Helas taken over by MPI Mainz. On the outward journey, an ozone minimum was observed in the area of the ITCZ (7°N), as is typical for conditions with high levels of solar radiation and low vertical mixing. Further trace substances (NOx; HNO₃; krypton-85, aerosol) were measured on this trip.