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The oceanic response to imposed changes in the latitude of the subpolar westerly winds (SWWs) over the Southern Ocean is assessed in a global ocean model. The latitude changes are achieved by applying a zonally uniform zonal wind stress anomaly that is quasi-sinusoidal in latitude, with a positive (negative) band to the south (north) of about 50ЊS. This(More)
Coordinated Ocean-ice Reference Experiments (COREs) are presented as a tool to explore the behaviour of global ocean-ice models under forcing from a common atmospheric dataset. We highlight issues arising when designing coupled global ocean and sea ice experiments, such as difficulties formulating a consistent forcing methodology and experimental protocol.(More)
A global, flux-corrected climate model is employed to predict the surface wind stress and associated wind-driven oceanic circulation for climate states corresponding to a doubling and quadrupling of the atmospheric CO 2 concentration in a simple 1% per year CO 2 increase scenario. The model indicates that in response to CO 2 increase, the position of zero(More)
An eddying global model is used to study the characteristics of the Antarctic Circumpolar Current (ACC) in a streamline-following framework. Previous model-based estimates of the meridional circulation were calculated using zonal averages: this method leads to a counter-intuitive pole-ward circulation of the less dense waters, and underestimates the eddy(More)
We develop the theory of Abelian functions defined using a tetrag-onal curve of genus six, with the specific example of the cyclic curve, y 4 = x 5 + λ 4 x 4 + λ 3 x 3 + λ 2 x 2 + λ 1 x + λ 0 discussed in detail. We define gener-alisations of the Weierstrass σ and ℘ functions, along with additional classes of Abelian functions. In addition, we present the(More)
This article makes the key observation that when using cylindrical algebraic decomposition (CAD) to solve a problem with respect to a set of polynomials, it is not always the signs of those polynomials that are of paramount importance but rather the truth values of certain quantifier free formulae involving them. This motivates our definition of a Truth(More)
—In considering the reliability of numerical programs , it is normal to " limit our study to the semantics dealing with numerical precision " (Martel, 2005). On the other hand, there is a great deal of work on the reliability of programs that essentially ignores the numerics. The thesis of this paper is that there is a class of problems that fall between(More)
Cylindrical algebraic decomposition (CAD) is an important tool for the study of real algebraic geometry with many applications both within mathematics and elsewhere. It is known to have doubly exponential complexity in the number of variables in the worst case, but the actual computation time can vary greatly. It is possible to offer different formulations(More)
A new algorithm to compute cylindrical algebraic decompo-sitions (CADs) is presented, building on two recent advances. Firstly, the output is truth table invariant (a TTICAD) meaning given formulae have constant truth value on each cell of the decomposition. Secondly, the computation uses regular chains theory to first build a cylindrical decomposition of(More)