Imperial College London
Alternate

ProfessorGrahamHughes

Faculty of Engineering, Department of Civil and Environmental Engineering

Chair in Environmental Fluid Mechanics
 
 
 
//

Contact

 

+44 (0)20 7594 9701g.hughes

 
 
//

Location

 

332Skempton BuildingSouth Kensington Campus

//

Summary

 

Publications

Citation

BibTex format

@article{Saenz:2015:10.1175/JPO-D-14-0105.1,
author = {Saenz, JA and Tailleux, R and Butler, ED and Hughes, GO and C'Oliver, KI},
doi = {10.1175/JPO-D-14-0105.1},
journal = {Journal of Physical Oceanography},
pages = {1242--1257},
title = {Estimating Lorenz’s Reference State in an Ocean with a Nonlinear Equation of State for Seawater},
url = {http://dx.doi.org/10.1175/JPO-D-14-0105.1},
volume = {45},
year = {2015}
}
Download

RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The study of the mechanical energy budget of the oceans using the Lorenz available potential energy (APE) theory is based on knowledge of the adiabatically rearranged Lorenz reference state of minimum potential energy. The compressible and nonlinear character of the equation of state for seawater has been thought to cause the reference state to be ill defined, casting doubt on the usefulness of APE theory for investigating ocean energetics under realistic conditions. Using a method based on the volume frequency distribution of parcels as a function of temperature and salinity in the context of the seawater Boussinesq approximation, which is illustrated using climatological data, the authors show that compressibility effects are in fact minor. The reference state can be regarded as a well-defined one-dimensional function of depth, which forms a surface in temperature, salinity, and density space between the surface and the bottom of the ocean. For a very small proportion of water masses, this surface can be multivalued and water parcels can have up to two statically stable levels in the reference density profile, of which the shallowest is energetically more accessible. Classifying parcels from the surface to the bottom gives a different reference density profile than classifying in the opposite direction. However, this difference is negligible. This study shows that the reference state obtained by standard sorting methods is equivalent to, though computationally more expensive than, the volume frequency distribution approach. The approach that is presented can be applied systematically and in a computationally efficient manner to investigate the APE budget of the ocean circulation using models or climatological data.
AU  - Saenz,JA
AU  - Tailleux,R
AU  - Butler,ED
AU  - Hughes,GO
AU  - C'Oliver,KI
DO  - 10.1175/JPO-D-14-0105.1
EP  - 1257
PY  - 2015///
SN  - 0022-3670
SP  - 1242
TI  - Estimating Lorenz’s Reference State in an Ocean with a Nonlinear Equation of State for Seawater
T2  - Journal of Physical Oceanography
UR  - http://dx.doi.org/10.1175/JPO-D-14-0105.1
UR  - http://hdl.handle.net/10044/1/40695
VL  - 45
ER  -
Download