Interpentadal variability of salinity in the upper 150 m of the North Atlantic Ocean, 1970–1974 versus 1955–1959

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‰. The northern portion of the subtropical gyre increased in salinity by as much as 0.4‰, while the interior of this gyre decreased in salinity.