The second example shown in Fig. 14, float 3900222,
spent nearly two years in the low salinity region off the southern
west coast of Chile, the formation region of the low
salinity AAIW variety that dominates the eastern South Pacific
(Fig. 5). During most of the time the AAIW properties
recorded by the float agreed well with the climatological
mean. But for a period of some 120 days it encountered
a variety of AAIW with significantly higher salinity. The
records suggests that the boundary between the two varieties
had the character of a well defined front: The salinity record
switches back and forth between salinities around 34.25 and