Physical Oceanography, Vol.
ANALYSIS OF OBSERVATIONS AND METHODS FOR CALCULATING
HYDROPHYSICAL FIELDS IN THE OCEAN
PRACTICAL FORMULAS FOR INTERCOUPLING OF PRESSURE AND DEPTH
IN THE BLACK SEA
V. I. Zaburdaev and P. V. Gaiskii
On the basis of the generalization of the concept of “standard” ocean to the Black Sea, we deduce
practical formulas for the conversion of pressure into depth and vice versa depending on the lat-
itude of the place with regard for the equation of state for 1980. The error of these relations for
the “standard” Black Sea (whose salinity is equal to
at a temperature of
from the sur-
face to the bottom) does not exceed
dbar. The difference between the “practi-
cal” and actual depths in winter and summer periods does not exceed
for depths vary-
ing within range
m. The proposed practical formulas enable one to simplify the proce-
dure of rapid evaluation of depth (or pressure) in real time by excluding the procedure of inte-
gration over a specific volume.
The formulas for conversion of hydrostatic pressure into depth for seawater with oceanic salt composition
were proposed by Saunders and Fofonoff  and Fofonoff and Millard, Jr. .
These formulas are based on the equation of hydrostatics written in the integral form
gdz s t p dp
= v( , , ) , (1)
where z is depth, g is the acceleration of gravity, p is hydrostatic pressure, and
v(,, )st p is the specific vol-
ume of seawater with salinity s at temperature t under pressure p (the in-situ specific volume).
Integrating the left-hand side of Eq.
(1) and using the dependence of the acceleration of gravity on depth
(pressure) in the explicit form, we obtain
()ϕ is the acceleration of gravity on the sea surface represented as a function of the geographical lati-
tude ϕ, γ
m), characterizes the dependence of the acceleration of gravity on depth (on the
distance to the center of Earth), and γ
dbar), characterizes the dependence of the accelera-
tion of gravity on hydrostatic pressure.
Marine Hydrophysical Institute, Ukrainian Academy of Sciences, Sevastopol. Translated from Morskoi Gidrofizicheskii Zhurnal,
27–34, November–December, 2002. Original article submitted June 22, 2001.
0928-5105/02/1206–0323 $27.00 © 2002 Plenum Publishing Corporation 323