Idealised simulations of cyclones with robust symmetrically-unstable sting jets

Idealised simulations of Shapiro-Keyser cyclones developing a sting jet (SJ) are presented. Thanks to an improved and accurate implementation of thermal wind balance in the initial state, it has been possible to use more realistic environments than in previous idealised studies. As a consequence, this study provides further insight in SJ evolution and dynamics and explores SJ robustness to different environmental conditions, assessed via a wide range of sensitivity experiments. The control simulation contains a cyclone that fits the Shapiro-Keyser conceptual model and develops a SJ whose dynamics are associated with the evolution of mesoscale instabilities along the airstream, including symmetric instability (SI). The SJ undergoes a strong descent while leaving the cloud-head banded tip and markedly accelerating towards the frontal-fracture region, revealed as an area of buckling of the already-sloped moist isentropes. Dry instabilities, generated by vorticity tilting via slantwise frontal motions in the cloud head, exist in similar proportions to moist instabilities at the start of the SJ descent and are then released along the SJ. The observed evolution supports the role of SI in the airstream’s dynamics proposed in a conceptual model outlined in a previous study. Sensitivity experiments illustrate that the SJ is a robust feature of intense Shapiro-Keyser cyclones, highlighting a range of different environmental conditions in which SI contributes to the evolution of this airstream, conditional on the model having adequate resolution. The results reveal that several environmental factors can modulate the strength of the SJ. However, a positive relationship between the strength of the SJ, both in terms of peak speed and amount of descent, and the amount of instability occurring along it can still be identified. In summary, the idealised simulations presented in this study show the robustness of SJ occurrence in intense Shapiro-Keyser cyclones and support and clarify the role of dry instabilities in SJ dynamics

Louis XVI’s Chapel during the French Revolution 1789-1792

Abstract — The close association of Christianity with the late Bourbon monarchy’s style of governance has often been interpreted as a burdensome legacy, which impacted greatly on the period preceding the French Revolution. In recent years, historians have referred to the ideological, juridical and intellectual assaults on the religious foundations of the French crown, throughout the eighteenth century, either as a process of ‘ desacralization ’ or as the religious origins of the French Revolution. This article, though inspired by this school of thought, takes a different approach by examining the less well-known ceremonial and ritual components of this form of kingship, with particular reference to the king’s chapel. Louis XVI’s ecclesiastical household was both the centre of royal patronage for the Gallican Church and the chief regulatory authority of the monarch’s personal religious devotion. Its actions, transformation and fate during the Revolution are instructive in two ways. First, its survival during the first three years of the revolutionary troubles highlights its fundamental and constraining influence over the French monarchy. Secondly, the gradual, though determined, effort to undermine the pact between throne and altar that it represented exemplifi es a lesser known aspect of the national deputies ’ anticlerical agenda

Louis XVI and Marie Antoinette

The important role played by Louis XVI and Marie Antoinette in the radicalization of the early phase of the French Revolution has never been in doubt. Most histories continue to focus on the regal couple’s real, and supposed, role in fomenting counter-revolution at home and especially abroad. This chapter engages with the complex question of the dwindling fortunes of Louis XVI’s monarchy from a more domestic angle. It focuses on that neglected, though crucial, year of 1790 which witnessed the failure to erect a viable constitutional settlement. It became impossible to accommodate both Crown and assembly in a viable working relationship. Essentially, the king’s distrust for the deputies, who had little by little arrogated his remaining powers, proved insurmountable. The monarchy’s passive resistance to the revolution’s early reform programme and political culture became increasingly unpopular. This created a radicalized and tension-filled atmosphere which pushed the revolution into hitherto unexpected directions

Collaborators, Collaboration, and the Problems of Empire in Napoleonic Italy, The Oppizzoni Affair, 1805-1807

The recent bicentennial commemorations of the Napoleonic empire have witnessed a proliferation of new studies. Scholars now possess much more sophisticated conceptual tools than in past decades with which to gauge the problems faced by French imperial administrators throughout Europe. Well-trodden concepts, like centre/periphery or collaboration/resistance, have been reinvigorated by more sophisticated understandings of how rulers and ruled interacted in the early nineteenth century. This article argues that, while much progress has been made in understanding problems of ‘resistance’, there is more to be said about the other side of the same coin, namely: ‘collaboration’. Using the micro/local history of a scandal in Napoleonic Bologna, this article wishes to reaffirm that collaboration was an active agent that shaped, and often shook, the French imperial project. The biggest problem remained that, despite ‘good intentions’, collaborators sometimes simply did not collaborate with each other. After all, imperial clients were determined to benefit from the experience of empire. The centre was often submerged by local petty squabbles. This article will use a specific micro-history in Bologna to highlight the extent to which Napoleonic empire builders had to thread a fine line between the impracticalities of direct control and the dangers of ‘going native’

Ornamentalism in a European Context? Napoleon’s Italian Coronation, 26 May 1805

Napoleon’s Italian Coronation has been neglected, or at best consigned to a footnote, by historical scholarship. The ceremony elicited immense expenditure and involved thousands of participants, but its true importance lay in the elusive, and somewhat confused, semiotic claims put forward by its organisers. The manner in which the events of May 1805 were choreographed reveal much about how French Imperialists viewed their nascent Empire and their relationship with their Northern Italian citizen-subjects. The argument put forward here is inspired by the concept of ‘ornamentalism.’ While the realities of imperial brutality, cultural chauvinism and economic exploitation over conquered territories cannot be brushed under the carpet, the reverse side of this coin is also worthy of further investigation. Nowhere more than in the satellite Kingdom of Italy did Napoleon seek to promote collaboration and local investment in his supranational Empire. He rewarded, honoured and rallied his Lombard and Emilian officials to endow them with a sense that they belonged to, and benefited from membership, of the wider imperial community. The Coronation in Milan, on 26 May 1805, was an essential experiment in the creation of new hierarchies and elite affinities. It left a mixed, though significant, legacy which was continued, to a certain extent, by Napoleon’s Habsburg successors well into the first half of the nineteenth century

Esperimento RTK1: verifica delle prestazioni del posizionamento NRTK (Cap. 4 app. 1)

Un libro bianco su: "I servizi di posizionamento satellitare per l'e-government