Db. Chelton et al., GEOGRAPHICAL VARIABILITY OF THE FIRST BAROCLINIC ROSSBY RADIUS OF DEFORMATION, Journal of physical oceanography, 28(3), 1998, pp. 433-460
Global 1 degrees x 1 degrees climatologies of the first baroclinic gra
vity-wave phase speed c(1) and the Rossby radius of deformation lambda
(1) are computed from climatological average temperature and salinity
profiles. These new atlases are compared with previously published 5 d
egrees x 5 degrees coarse resolution maps of lambda(1) for the Norther
n Hemisphere and the South Atlantic and with a 1 degrees x 1 degrees f
ine-resolution map of c(1) for the tropical Pacific. It is concluded t
hat the methods used in these earlier estimates yield values that are
biased systematically low by 5%-15% owing to seemingly minor computati
onal errors. Geographical variations in the new high-resolution maps o
f c(1) and lambda(1) are discussed in terms of a WKB approximation tha
t elucidates the effects of earth rotation, stratification, and water
depth on these quantities. It is shown that the effects of temporal va
riations of the stratification can be neglected in the estimation of c
(1) and lambda(1) at any particular location in the World Ocean. This
is rationalized from consideration of the WKB approximation.