The floats did not spend their lives in a data-sparse region
(compare Fig. 6), and there is no reason to think that the
AAIW salinity field given by the World Ocean Atlas should
not be accepted as representative of the long term mean situation
north east of New Zealand. This suggests that Antarctic
Intermediate Water that reached the area was about 0.03–
0.06 less saline during the years 2001–2005 than the climatological
average. One possible explanation can be found
in the time difference between the Argo data and the WOA.
All data of WOA 2001 were taken before the first Argo float
was deployed in the region, and the bulk of the WOA 2001
data stems from earlier decades. Wong et al. (1999) found
a freshening of AAIW in South Pacific transects along 32◦ S
of 0.03–0.06 over a time span of twenty years, comparable to
the difference found here between the Argo data and WOA
2001.