Dr. Alex Megann
James Rennell Division for Ocean Circulation and Climate
Southampton Oceanography Centre
Empress Dock, Southampton
SO14 3ZH, UK
Tel : +44 (0)23 80 596645
Fax : +44 (0)23 80 596204
Email:apm@soc.soton.ac.uk.
GLOBAL MODEL INTERCOMPARISON. I set up an isopycnic-coordinate ocean
model based on the Miami Isopycnic-Coordinate Ocean Model (MICOM), but
with the then novel enhancements of global wrap-around and arbitrary
grid aspect ratio (both now established in MICOM versions 2.8 onward),
as part of a contract with the Hadley Centre, part of the UK Met.
Office.
The model was analysed along with the Hadley Centre's own ocean model,
with particular emphasis on the seasonal cycle in the north Atlantic,
and on the path of the major current systems.
ARCTIC MODELLING. I developed a technique for reduced timesteps in the
Arctic to allow the model grid to be extended as far as the North Pole,
and added the ice model from the Met. Office Unified Model.
Comparison with the results from the quasi-global model confirmed
that the seas north of 75oN are important in the wintertime
production of dense bottom water, and that they should be included
in any future large scale model.
DYNAMICS OF THE EQUATORIAL PACIFIC. This included a study of the effects
of resolution and viscosity on the structure of the equatorial
current system, and a detailed examination of the momentum budget
in a suite of models with varying resolution and viscosity.
MODEL DEVELOPMENT. I am setting up an implementation of the Hybrid
Coordinate Ocean Model (HYCOM) in the tropical Pacific to determine
the sensitivity of the equatorial current system to the coordinate
system and the mixed layer scheme used in the model.
COUPLED OCEAN-ATMOSPHERE MODELLING. I am developing a coupled model
with a hybrid-coordinate ocean component: the Coupled Hadley-Isopycnic
Model Experiment (CHIME).
This will be at the heart of a project to study the interannual and
decadal variability of in the North Atlantic, supported by the the NERC
Coupled Ocean-Atmosphere Processes and effects on European
Climate (COAPEC)
thematic programme.
The ocean component of CHIME is a global implementation of the Hybrid
Coordinate Ocean Model (HYCOM) on a 1.25o by 1.25o
grid with a bipolar patch over the Arctic to avoid introducing a
singularity at the North Pole.
I am also working with Bablu Sinha on the development of the coupled model
which will use HYCOM as the ocean component and the Hadley Centre
atmospheric model, which will be used in the CHIME project.
2000
Marsh, R., A.J.G. Nurser, A.P. Megann and A.L. New, 2000: Water mass transformation in the Southern Ocean of a global isopycnic coordinate GCM. J. Phys. Oceanogr., 30, 1013-1045. PDF version
2001
Megann, A.P. and A.L. New, 2001. The Effects of Resolution and Viscosity in an Isopycnic-Coordinate Model of the Equatorial Pacific. J. Phys. Oceanogr. 31, 1993-2018. PDF version
2002
Marsh, R. and A. P. Megann, 2002. Tracing water masses with particle trajectories in an isopycnic-coordinate model of the global ocean. Ocean Modelling, 4, 27-53.
In Preparation
Megann, A.P., 2002. The Zonal Momentum Budget of the Pacific Equatorial Undercurrent in an Isopycnic-Coordinate Model. Submitted to J. Phys. Oceanogr., December 2001.
Last Updated: December 2001