We describe a major extension to the Contour-Advective Semi-Lagrangian (CASL) algorithm (Dritschel & Ambaum, 1997, 2006). The extension, called ‘HyperCASL’ (HCASL), uses Lagrangian advection of material potential vorticity contours like CASL, but a Vortex-In-Cell (VIC) method for the treatment of diabatic forcing or damping. In this way, HyperCASL is fully Lagrangian regarding advection. A grid...

the spontaneous generation of inertia–gravity waves (igws) in the idealized simulation of vortical flows is investigated using the isentropic two-layer model on a sphere. the contour-advective semi-lagrangian (casl) algorithm is applied to solve the primitive equations using the potential vorticity (pv), velocity divergence, and acceleration divergence as the prognostic variables. the casl algo...

We present and test a new hybrid numerical method for simulating layerwise-twodimensional geophysical flows. The method radically extends the original ContourAdvective Semi-Lagrangian (CASL) algorithm (Dritschel & Ambaum, 1997) by combining three computational elements for the advection of general tracers (e.g. potential vorticity, water vapor, etc.): (1) a pseudo-spectral method for large scal...

Contour crossings are a form of numerical error common to contour dynamical and contour-advective simulations of geophysical fluid flows. This thesis is devoted to the study of contour crossings that occur in simulations of fluid motion performed by the Contour-Advective Semi-Lagrangian (CASL) algorithm. Components of the CASL algorithm relevant to the study of contour crossings are discussed. ...

This paper presents a static semantic analysis for CASL, the Common Algebraic Speciication Language. Abstract syntax trees are generated including subsorts and overloaded functions and predicates. The static semantic analysis, through the implementation of an overload resolution algorithm, checks and qualiies these abstract syntax trees. The result is a fully qualiied CASL abstract syntax tree ...

We present DO-Casl, a new member of the CASL family of specification languages. It is an extension of Casl-Ltl and it supports a methodology for conveniently writing loose specifications of observers on dynamic sorts. The need for such constructs arose during the development of a CASL library for distributed systems. Indeed, we have frequently used the same pattern of specification, in order to...

Casl is an expressive language for the algebraic specification of software requirements, design, and architecture. It has been developed by an open collaborative effort called CoFI (Common Framework Initiative for algebraic specification and development). Casl combines the best features of many previous algebraic specification languages, and it is hoped that it may provide a focus for future re...

In this paper we present a part of Casl-Mdl, a visual modelling notation based on Casl-Ltl (an extension for dynamic system of the algebraic specification language Casl). The visual constructs of Casl-Mdl have been borrowed from the UML, thus existing editors may be used. A Casl-Mdl model is a set of diagrams but it corresponds to a Casl-Ltl specification, thus Casl-Mdl is a suitable means to e...

Csp-Casl [7] is a comprehensive specification language which combines processes written in the process algebra Csp [2, 8] with the specification of data types formulated in algebraic specification language Casl [5]. Recent developments on Csp-Casl cover tool support [6] as well as testing from Csp-Casl specifications [3]. In this talk we address the question of how to formulate Csp-Casl as an i...

The language Csp-Casl combines specifications of data and processes. We give an institution based semantics to Csp-Casl that allows us to re-use the institution independent structuring mechanisms of Casl. Furthermore, we extend Csp-Casl with a notion of refinement that reconciles the differing philosophies behind the refinement notions for Csp and Casl. We develop a compositional proof calculus...