# gsw_Nsquared_lowerlimit

**specified profile of minimum buoyancy frequency squared**

## Contents

## USAGE:

Nsquared_lowerlimit = gsw_Nsquared_lowerlimit(p,long,lat)

## DESCRIPTION:

Calculates the minimum Nsquared such that a cast is stable.

## INPUT:

p = sea pressure [ dbar ]
( i.e. absolute pressure - 10.1325 dbar )
long = longitude in decimal degrees [ 0 ... +360 ]
lat = latitude in decimal degrees north [ -90 ... +90 ]

lat & long may have dimensions 1x1 or Mx1 or 1xN or MxN, where p is MxN.

## OUTPUT:

Nsquared_lowerlimit = Minimum Brunt-Vaisala Frequency squared [rad^{2} s^{-2} ]

The units of N^{2} are radians^{2} s^{-2} however in may textbooks this is
abreviated to s^{-2} as radians does not have a unit. To convert the
frequency to hertz, cycles sec^{-1}, divide the frequency by 2π, ie N/(2π).

## EXAMPLE:

p = [ 10; 50; 125; 250; 600; 1000;]
long = 180;
lat = 4;

N2_lowerlimit = gsw_Nsquared_lowerlimit(p,long,lat)

N2_lowerlimit =

1.0e-07 *

0.992537375311876
0.963422068375535
0.911872676938447
0.834100587303554
0.661608727070520
0.525909580878582

## AUTHOR:

Paul Barker and Trevor McDougall. [ help@teos-10.org ]

## VERSION NUMBER:

3.06.13 (4th August, 2021)

## REFERENCES:

Barker, P.M., and T.J. McDougall, 2016: Stabilisation of hydrographic
profiles. *J. Atmosph. Ocean. Tech.*, submitted.

IOC, SCOR and IAPSO, 2010: The international thermodynamic equation of
seawater - 2010: Calculation and use of thermodynamic properties.
Intergovernmental Oceanographic Commission, Manuals and Guides No. 56,
UNESCO (English), 196 pp. Available from the TEOS-10 web site.

The software is available from http://www.TEOS-10.org