Levitus, S., 1989: Interpentadal variability of salinity in the upper 150 m of the North Atlantic Ocean, 1970-1974 versus 1955-1959. Journal of Geophysical Research, 94 (C7), 9679-9685.

Abstract: We have composited and objectively analyzed historical hydrographic observations for the North Atlantic Ocean for two pentads, 1955-1959 and 1970-1974. Our purpose is the study of the temporal variability of salinity in the upper layers of the North Atlantic Ocean. Upper ocean (0-150 m) salinity differences between the two pentads exhibit statistically significant changes. The subarctic gyre east and north of Newfoundland freshened by as much as 0.5%o. The northern portion of the subtropical gyre increased in salinity by as much as 0.4%o, while the interior of this gyre decreased in salinity.