28th International Liège Colloquium on Ocean Hydrodynamics
Modelling hydrodynamically dominated marine ecosystems
Liège, May 6-10 1996
Modelling ecosystems in a sustainable development
perspective is a truly interdisciplinary challenge.
Biogeochemical cycles cannot be considered independently of
the hydrodynamic constraints exerted on them.
Hydrodynamic processes the time scales of which correspond
to the time scales of biological populations, capture these
populations in their physical spatial structures (the so-called
"ecohydrodynamic adjustment") and the frequency and persistence
of the latter command the speed of the exchanges between the
marine biosphere, the ocean reservoirs and the atmosphere.
It is difficult to see how a simple model could be used to
describe ecosystems and biogeochemical cycles. On the one hand,
geochemical and ecological processes are strongly correlated with
physical processes by the resonant interactions and subsequent
scale matching of the ecohydrodynamic adjustment; in addition,
they live on nutrient supplies which are partly regenerated in
the water column - hence subject to the caprices of local
hydrodynamics -, partly imported into the system through the
boundaries (bottom-sediments, coasts, air-sea interface,...)
with a spatial variability which, inevitably, is imprinted on the
system's kinetics. On the other hand, the complexity and
diversity of ecological and geochemical interactions webs leaves
little hope for the development of realistic management models
including too simpliste biology and geochemistry.
Yet, there are limitations, -if not on computing power and
computing time in a foreseeable future-, on the volume of
computer products, the -technical and human- ways and means of
exploiting them for the advancement of our basic scientific
understanding or the development of rational management schemes,
in any reasonable time.
A trade-off must be found between physical and
biogeochemical complexity of the models.
When the hydrodynamic constraints play a cogent part (as in
fronts, upwellings...), there is a tendency among the
hydrodynamicists to investigate the physics in details and try to
get away with a very simple representation of the biology.
The purpose of the Colloquium is to provide a forum for
discussing the success and shortcomings of these
hydrodynamics-dominated models, inviting biologists and
geochemists to report their own progresses (approaching the system
from the other side, so to say) and identify the bases for the
development of models of optimal complexity.
A. Berger, Institut d'Astronomie et de Géophysique, University of Louvain, Belgium.
M. Fasham, James Rennel Centre for Ocean Circulation, Southampton, U.K.
E.E. Hofmann, Centre for Coastal Physical Oceanography, Old Dominion University, USA.
S.E. Jorgensen, University of Copenhagen, Denmark.
T. Komatsu, Ocean Research Institute, University of Tokyo, Japan.
L. Legendre, Université Laval, Québec, Canada.
C. Moloney, University of Cape Town, South Africa.
J.C.J. Nihoul (Chairman), GHER, University of Liège, Belgium.
G. Radach, Institüt fur Meereskunde, Universität Hamburg,
A. Robinson, Division of Applied Science, Harvard
University, USA (Chairman of the Globec Modelling Group).
B. Rotschild, Chesapeak Biological Laboratory, USA.
J.O. Strømberg, Kristineberg Marine Laboratory Biological
Station, Fiskebackskil, Sweden.
J.J. Walsh, Departement of Marine Science, University of
S. Djenidi (Chairman)
Ch. Winand (Secretary)
GHER - Modelenvironment
University of Liège
Sart Tilman, B5
B-4000 Liège, Belgium
Phone : +32 41 66 33 50
Fax : +32 41 66 23 55
e-mail : firstname.lastname@example.org
The members of the Organizing Committees wish to express their gratitude to the :
- Commission of the European Union
- Fonds National de la Recherche Scientifique (FNRS, Belgium)
- Institut de Recherche Marines et d'interactions Air-mer (IRMA, Belgium)
- Intergovernmental Oceanographic Commission of the UNESCO (IOC)
- International Association for the Physical Sciences of the Ocean (IAPSO)
- Ministère de l'Enseignement supérieur et de la Recherche scientifique (Belgium)
- National Science Foundation (NSF, USA)
- Office of Naval Research (ONR, USA)
- Scientific Council on Oceanic Research (SCOR, XSU)
- Province de Liège
- Université de Liège