A review of forecast error covariance statistics in atmospheric variational data assimilation. I: Characteristics and measurements of forecast error covariances

The calculation of accurate normal coordinates I: general theory, and application to methane

The calculation of accurate and reliable vibrational potential functions and normal co-ordinates is discussed, for such simple polyatomic molecules as it may be possible. Such calculations should be corrected for the effects of anharmonicity and of resonance interactions between the vibrational states, and should be fitted to all the available information on all isotopic species: particularly the vibrational frequencies, Coriolis zeta constants and centrifugal distortion constants. The difficulties of making these corrections, and of making use of the observed data are reviewed. A programme for the Ferranti Mercury Computer is described by means of which harmonic vibration frequencies and normal co-ordinate vectors, zeta factors and centrifugal distortion constants can be calculated, from a given force field and from given G-matrix elements, etc. The programme has been used on up to 5 × 5 secular equations for which a single calculation and output of results takes approximately l min; it can readily be extended to larger determinants. The best methods of using such a programme and the possibility of reversing the direction of calculation are discussed. The methods are applied to calculating the best possible vibrational potential function for the methane molecule, making use of all the observed data.

Addressee orientation in political speeches: tracing the dialogical 'other' in argumentative monologue

This article suggests that the addressees as the dialogical ‘other’ loom large in monological political speeches. However, political speeches are produced under conditions of addressee heterogeneity, i.e. the speakers do not actually know who they will be talking to. It will be argued that the addressees are nevertheless a crucial element in speakers’ context models, that speakers orientate towards imagined addressees and that certain aspects – what possible addressees may do, think or believe and that they are a part of an imagined community – are particularly relevant from the speakers’ point of view. An analysis of addressee orientation in political speeches aims at reconstructing speakers’ conceptualisations of possible addressees. The analysis reveals patterns of addressee orientation which suggest that the addressees are framed in terms of presumed nearness (i.e. agreement) or distance (i.e. disagreement) to the speakers. Both presumed agreement and disagreement will be discussed in terms of how the speakers aim to impose their default perspectives on the addressees. The analysis is based on examples from a substantial corpus of German chancellors’ political speeches from 1951-2001.