The extraction of a salinity minimum time series representative of AAIW relies on the existence of an intermediate salinity minimum between 500m and 1200m depth. Some floats occasionally generated profiles that reached below 500m depth but did not extend deep enough to capture the salinity minimum. Such profiles were accepted if their total number was small compared to the length of the time series and if the salinity at the deepest level was very close to the minimum salinity found in the remainder of the profiles; the salinity at the deepest level was used as the salinity minimum in these cases. Other floats generated profiles with no intermediate minimum in the entire 500m–1200m depth range. (This occurred particularly when a float drifted too far south into the region where the salinity minimum comes closer to the surface.) Such profiles were excluded from the analysis