Chapter 5
NESTING OCEAN MODELS
Eric Blayo and Laurent Debreu
LMC-IMAG and INRIA Rhˆ one-Alpes, Grenoble, France
Abstract
This note is focused on the problem of providing boundary conditions
for regional ocean models. It is shown that usual methods generally do
not address the correct problem, but more or less approaching ones. A
tentative classification of these methods is proposed. Then their theoretical foundations are discussed, and recommendations are given.
Keywords: Open boundary conditions, regional models, nesting.
1.
Introduction
The use of high resolution regional ocean models has become widespread in recent years, in particular due to the development of operational oceanography and coastal management systems. An important
point, that has a strong influence on the quality of the results, is the way
that a local model is forced at its open boundaries. Several methods,
whose precise contents, theoretical justification, and practical performances are often somewhat difficult to compare precisely, are presently
used in actual applications. In this context, the first aim of this note is
to provide a tentative classification of these methods (section 1). Then
we will discuss the one-way (section 2) and two-way (section 3) interactions, focusing on the theoretical foundations and practical use of the
different approaches. Some final remarks on the available software tools
and on the problem of data assimilation within nested models are given
in sections 4 and 5.
:
127
E. P. Chassignet and J. Verron (eds.), Ocean Weather Forecasting, 127-146.
© 2006 Springer Printed in the Netherlands.
.
NESTING OCEAN MODELS
Eric Blayo and Laurent Debreu
LMC-IMAG and INRIA Rhˆ one-Alpes, Grenoble, France
Abstract
This note is focused on the problem of providing boundary conditions
for regional ocean models. It is shown that usual methods generally do
not address the correct problem, but more or less approaching ones. A
tentative classification of these methods is proposed. Then their theoretical foundations are discussed, and recommendations are given.
Keywords: Open boundary conditions, regional models, nesting.
1.
Introduction
The use of high resolution regional ocean models has become widespread in recent years, in particular due to the development of operational oceanography and coastal management systems. An important
point, that has a strong influence on the quality of the results, is the way
that a local model is forced at its open boundaries. Several methods,
whose precise contents, theoretical justification, and practical performances are often somewhat difficult to compare precisely, are presently
used in actual applications. In this context, the first aim of this note is
to provide a tentative classification of these methods (section 1). Then
we will discuss the one-way (section 2) and two-way (section 3) interactions, focusing on the theoretical foundations and practical use of the
different approaches. Some final remarks on the available software tools
and on the problem of data assimilation within nested models are given
in sections 4 and 5.
:
127
E. P. Chassignet and J. Verron (eds.), Ocean Weather Forecasting, 127-146.
© 2006 Springer Printed in the Netherlands.
.