Float 3900121 spent 700 days in the low salinity region
of the subtropical eastern South Pacific. An initial westward
excursion during the first 100 days was followed by a return
to the original launching region. Based on the WOA data this
should have resulted in a rise and fall of the AAIW salinity
minimum during the first 150 days. The Argo observations
show several short-lived events of higher AAIW salinity during
that period, which is dominated by AAIW salinities below
34.27. Agreement between the WOA field and the float
observations is reached after the first 250 days. This suggests
that in 2004 the region of AAIW salinities