dbar

decibar

Pressureexact by definition

The decibar is exactly 10⁴ pascals, one tenth of a bar. It is the unit of physical oceanography for a specific and useful reason: a change of one decibar corresponds almost exactly to a change of one metre of depth in seawater, so a pressure profile in decibars can be read directly as a depth profile in metres.

Watch out: The correspondence is a convenient approximation and not a definition. It drifts with latitude, temperature and salinity, and by several thousand metres depth the accumulated difference between decibars and metres is a couple of percent.

1 dbar 10 kPa