Tropical nightglow observations and predictions from ionospheric models

To study the tropical nightglow emissions in the vicinity of the Brazilian magnetic anomaly, two balloons were flown in February 1973 and 1977 carrying photometers. The behaviour in the tropical nightglow of the 630 and 557.7 nm lines is described and compared with predictions based on recent ionospheric models. Possible effects of the magnetic activity on the F2-layer in the tropics are suggested which are not accounted for by the ionospheric models.     

Gravity wave activity in the upper mesosphere over Urbana,Illinois: lidar observations and analysis of gravity wave propagation models

We analyze 375 h of Na Wind/Temperature lidar measurements of the mesopause region (≈ 80–105 km) Na density and temperature profiles on 57 nights distributed over 2 yr at Urbana, Illinois. These observations yield a high-resolution seasonal data set of gravity wave activity in the upper mesosphere. From this data, we present measurements of the Brunt-Väisälä period, the relative atmospheric density perturbations and their spectra, and the parameters of 143 quasi-monochromatic gravity waves. The direct measurement of the Brunt-Väisälä period allows accurate calculation of the horizontal velocity perturbations and vertical displacement perturbations from the density measurements. The horizontal velocity and vertical displacement vertical wave number spectrum magnitudes and indices show considerable seasonal and nightly variability. The gravity wave amplitudes, wavelengths, and observed periods exhibit systematic relationships similar to those found in previous studies, and are consistent with the MU radar measurements of intrinsic gravity wave parameters. Here, we present a detailed analysis of the observations in terms of Diffusive-Filtering Theory models of gravity wave propagation. The magnitudes of the vertical wave number spectrum, the form of the joint vertical wave number and frequency spectrum, and the systematic relationships between the monochromatic gravity wave parameters are consistent with the Diffusive-Filtering model. We compare these results with a variety of radar, lidar, and airglow observations from other sites. This observational study suggests that the complex nonlinear interactions of the gravity wave field may be modeled successfully as a diffusive damping process, where the effective diffusivity is a function of the total wave variance.     

The Lilliputian dreams: preliminary observations of nationalism in Okinawa,Taiwan and Hong Kong

This paper is a preliminary comparative analysis of three polity‐seeking nationalisms that emerged in the contiguous peripheral areas – the overlapping ‘spheres of influence’ of three contending imperial centres: Taiwan, Okinawa and Hong Kong. Specifically, it examines and compares the pattern of nation‐formation and the form, ideology and politics of nationalism in each case, and in doing so it tries to suggest a possible explanatory framework for the rise of these nationalisms. Its tentative conclusion is that the rise of nationalism in Taiwan, Okinawa and Hong Kong should be understood as a macro‐historical sociological phenomenon caused by both the short‐term penetration from centralizing colonial and geopolitical centre(s) that triggered nationalist mobilization in the periphery and the long‐term process of peripheral nation‐formation that created the social basis for mobilization. The three cases also demonstrate some other traits of anti‐centre peripheral nationalism: they all adopted a similar ideological strategy of indigeneity, and all developed a differentiation between radical and pragmatic lines characteristic of minority or peripheral nationalisms. A final observation is that while the geopolitics of states in the region is powerfully shaping the development of the three nationalisms, interactions on the societal level may over time create a counterforce from below.     

The family,honour and gender in Sicily: models and new research*

This article shows how the latest research into Sicily's social and economic history calls into question certain well‐established interpretations of the history of the family and its structures, the paradigm of Mediterranean honour, and the theory of familism. This new appraisal also highlights the major significance of the history of women and gender identity.     

A sea of potential: The politics of global ocean observations

The Global Ocean Observing System (GOOS) is creating a new understanding of the world ocean. With a vast and heterogeneous network of sensors, it converts the ocean's properties into flows of information, creating a “data double” of a dynamic sea. This view of the ocean underlies not only international geopolitics but also more broadly emergent modes of government. This paper analyzes changing strategies for governing global ocean observations to better understand the shifting coconstitution of nature, technology, and politics. In particular, I inquire into the GOOS's recent developments, which indicate a new conception of the ocean as a space of potentiality. I argue that this emergent understanding poses problems for our conventional political analytics, particularly that of biopolitics. To account for this shift, I draw on and extend Elizabeth Povinelli's offering of geontopolitics, which identifies a departure from the fundamental distinctions between life and nonlife made by biopolitics, seeing instead the potential for unpredictable changes not only in human subjects but also in geophysical systems and the contemporary planetary environmental conditions they shape. Emphasizing how geontopolitics both names a new mode of government and signifes its limits, Povinelli suggests three figures, following Foucault's four figures of biopolitics. I conclude by suggesting the world ocean as a fourth figure of geonotopolitics, as that which is so imbricated with life as to be indistinct from it. Throughout, I maintain that like Foucault's figures of biopolitics, the world ocean must be understood as inseparable from the knowledge relations that make it legible.     

The height distribution of radio meteors: observations at 6 MHz

As part of a program aimed at deriving the true influx to the Earth of small meteoroids we have measured the height distribution of radio meteors to limiting magnitude + 6 (mass ~ 1.0 mg) at a frequency of 6 MHz for the combined Daytime Arietid and Zeta Perseid showers, and also for the Eta Aquarids; these showers have widely different velocities but no substantial dependence upon velocity is apparent. The distributions peak at ~ 105 km, 10 km above the peak found using conventional VHP meteor radars and in line with observations previously made by us at 2 MHz. Instrumental limitations confine the span of heights to 84 <h <116 km, but it is notable that within this range the 6 MHz height distributions appear to be symmetric, with a swift drop-off above 105 km; this contrasts with the asymmetric 2 MHz distribution which showed a slow drop-off with many meteors to 140 km. The origin of this difference is probably due to diffusion and the finite-velocity effect, which will be considered in a subsequent paper.     

The height distribution of radio meteors: observations at 2 MHz

Conventional meteor radars, operating at wavelengths of around 5–15 m, are unable to detect high-altitude meteors due to the wavelength-dependent echo ceiling. It is suggested that the ‘missing mass’ in the 10⁻⁶–10⁻² g range of interplanetary material is in fact a high-velocity component which is normally undetected since it ablates at high altitude. This contention is supported by previous work. In this paper we describe measurements of the heights of radio meteors (limiting magnitude about +7) at a wavelength of 150 m (frequency 2 MHz), for which the echo ceiling is above 140 km. The resultant true height distribution is found to peak at ~ 104 km, about 10 km above the peak found by conventional meteor radars. The majority of meteors are detected at or above this peak, and substantial numbers are seen right up to 140 km. It is therefore concluded that the ‘missing mass’, comprising the vast majority of the meteoric input to the atmosphere, ablates well above 100 km.     

The future of geomagnetic storm predictions: implications from recent solar and interplanetary observations

Within the last 7–8 years, there has been a substantial growth in our knowledge of the solar and interplanetary causes of geomagnetic storms at Earth. This review article will not attempt to cover all of the work done during this period. This can be found elsewhere. Our emphasis here will be on recent efforts that expose important, presently unanswered questions that must be addressed and solved before true predictability of storms can be possible. Hopefully, this article will encourage some readers to join this effort and perhaps make major contributions to the field.     

Formal models and formalist economic anthropology: The problem of maximization

Harold K. Schneider. Economic Man; The Anthropology of Economics. New York: The Free Press, 1974. x + 278 pp. Figures, glossary, bibliography, and index. $8.95.     

The E-region electron density diurnal asymmetry at Saint-Santin: observations and role of nitric oxide

Measurements of the E-region electron density were made with the Saint-Santin incoherent scatter radar during consecutive days in June 1978, March 1979 and December 1980. On the basis of a statistical study, the observations show the presence of a diurnal asymmetry of the electron density, with morning values usually exceeding the afternoon densities by 3–20%. Two possible causes of the dissymmetry are examined: the asymmetry in the diurnal variation of the neutral composition and the effect of nitric oxide. The presence of NO partly converts O₂⁺ into NO⁺ ions and increases the effective recombination rate of the electrons in the afternoon. Numerical simulations assessing the relative importance of the two factors are, in general, in good agreement with the measurements.     

The polis and the res publica: two Arendtian models of violence

The influence of the ancient Greek world on Hannah Arendt’s thought is well documented, yet her interest in the politics of the Roman Republic is often considered less central to her work. This paper explores Arendt’s analysis of both these political worlds, with a particular emphasis on what this comparison can tells us about her understanding of the role of violence in politics. Arendt has generally been understood to structurally exclude violence from the political, in part due to the claims she makes in her later essay ‘On Violence.’ Yet in her portrayal of Roman politics, and her preference for this political system above the Greeks’ (in certain respects), a genuinely political engagement with violence can be discerned. The paper claims that this particular case study indicates the framework of the vita activa, set out by Arendt in The Human Condition, should be reinterpreted, particularly insofar as ‘fabrication’ or ‘work’ here appears as something that is legitimately part of the political, and incorporates within it some forms of violence. The claims that violence is structurally anti-political, this paper concludes, are temporally specific to a twentieth-century context, rather than constituting a foundational ‘rule’ of political practice for Arendt.