About two-thirds of all float profiles reach 2000 decibars
. Because it takes a minimum of six months of data to calculate a final adjustment for salinity drift, less than 10% of the profiles are of the higher level quality-controlled delayed-mode data.
Its geopotential topography is expressed as the difference (in meters) in height between two defined isobaric surfaces, as for example the surface of the sea and the surface at 1,000 decibars
(a depth of about 3,280 ft, or 1,000 m).