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Mechanical Bathythermograph (MBT) Corrections

MBTs measure temperature down to the depth of 250m from the decks of slowly moving ships. The following studies attempt to correct a bias in MBT measurements created by systematic errors in depth (pressure) and temperature sensors.



Gouretski and Reseghetti Updated Corrections


Zcorrected = Zoriginal * Strech

Where sStretch is provided in table 1 at 1m depth interval.


Tcorrected = Toriginal - thermal_bias

Where the tThermal_bias is provided in table 2.

Gouretski and Reseghetti Original Corrections


Below 40 meters: S = 1 + b + a/Zoriginal, where S is the stretching , Zoriginal is the observed depth.

Above 40 meters: S = c + (Zoriginal - 5) * (d - c)/35, where d = 1 + b + a/40

The values of a, b and c for the years 1941 to 2003 are provided in table 1.

The corrected depth, Zcorrected = Zoriginal * S


Tcorrected = Toriginal - Thermal bias

Thermal bias for MBT for the years 1941 to 2003 are presented in table 2.