Storm after-effects observed at Ushuaia and Kerguelen

D-region disturbances have been detected at mid-latitudes after intense magnetic storms by means of a wide range of radiowave signals. Two different mechanisms have been suggested to account for these storm ‘after-effects’: one implies precipitation of energetic electrons from the radiation belt; the other, transport of neutral constituents from the auroral zones.This paper presents observations of abnormal enhancements of ionospheric absorption arising after two major magnetic storms occurring in March and April 1976. The measurements were made at Ushuaia (54.8°S, L = 1.7) and at Kerguelen (49.4°S, L = 3.7). The former were obtained by means of the pulse reflection method (A1) at MF and the latter by the riometer technique. It is shown that electron precipitation can explain the effects observed at Kerguelen but not those at Ushuaia which also depart significantly from the ‘winter anomaly’ trend observed at that site. The abnormal ionization at Ushuaia is attributed to transport from the southern auroral zone.     

Angular characteristics of radio pulses reflected from the subpolar ionosphere

This paper presents the results derived by measuring angular spectra of HF-radio pulses reflected from the subpolar ionospheric F2-region (62°N) using vertical-incidence soundings and a phase direction finder with Doppler filtering. The results correspond to three main types. One is the classical mirror reflection from the undisturbed ionospheric F2-region, typical of mid-latitudes (deviations from zenith do not exceed 3°; the angular spectrum width is less than 1°). The second type includes oblique diffuse reflections with a deviation from zenith of from 10 to 45°. The azimuth of arrival of these reflections is distributed in the range from 0 to 360°, the angular spectrum width is from 5 to 10°, and the range varies from 400 to 600 km. The third type includes anomalous mirror reflections with small deviations from zenith (not greater than 3°) but with substantially larger detection ranges (for example, 500km) as compared with the main reflections (250–300 km).     

Ledge effect in A1 absorption measurements

The short-term variability in A1 absorption measurements for Camden (34°S, 151°E) is caused by changes in the deviative component of absorption. These changes, in turn, are caused by enhanced electrondensity gradients (referred to here as ‘ledges’) near the reflection level. The ledges perturb the normal E-region electron density profile and introduce a bias (termed the ‘ledge effect’) into the absorption measurements. In the present experiment, the ledge effect was isolated by using the virtual reflection height information to interpret the A1 absorption measurements. During the period of this study (February 1980–January 1981), the ledge effect was observed to have both diurnal and seasonal variations. The effect was most noticeable in the afternoon around the equinoxes, but was essentially absent during the summer months.     

Field aligned airglow observations of transequatorial bubbles in the tropical F-region

It is possible to form images of the tropical F-region ionization structures, variously labelled as ‘bubbles’, ‘plumes’, or ‘depletions’, in a plane perpendicular to the magnetic field by observing the airglow emissions associated with them in a field aligned direction. Structures which are present at altitudes from 250 km to more than 700 km above the dip equator map down to the 250–350 km region, where recombination and associated airglow emissions occur, ranging from the equator to dip latitudes of 15° or more. The structures can be viewed in a field aligned direction from sites in the range 17°–23° dip latitude. Measurements with high angular resolution (as small as 0.1° in the meridian) could show structures as small as 2 km. It is possible to make simultaneous measurements in both 6300 and 7774 Å recombination emissions, from which the height h_max of the peak plasma concentration n(e)_max on the field line can be estimated from a ratio of the emission rates. It is possible to make maps of n(e)_max and h_max either by raster scanning the sky in the two emissions or by imaging them onto an imaging detector. Useful data can be obtained from one site over a range of 20° in dip latitude and 10° in dip longitude. Observations in the same magnetic meridian as a backscatter radar system are desirable, as also are observations from near magnetic conjugate points. Imaging characteristics for the observation sites in the range of dip latitude 17°–23° have been calculated.     

The influence of neutral temperatures and winds on the F-Iayer height

Observations of neutral winds and temperatures obtained using a FabryPerot interferometer at Beveridge (37°28′S, 145°6′E) have been combined with h'F measurements from ionosondes at Canberra (35°21′S, 149°10′E) and Hobart (42°54′S, 147° 12′E). Data from 16 nights have been used to study the response (height change) of the F2-layer to changes in neutral wind and temperature. The observations have been compared with the ‘servo’ model of Rishbeth. It is found that the ‘night stationary level’ of the F2-layer depends on temperature, with the height changing by (13 ± 6) km per 100K. This agrees well with the prediction of the ‘servo’ model. There is reasonable overall agreement between the observations and the model predictions for the change in height produced by a given meridional wind. However, there is considerable scatter in the individual comparisons due to the approximations used to apply the theory to the observations. In particular, the effect of electric fields on the F2-layer height has been ignored.     

HF observations of the vertical structure of mid-latitude spread-Es

The Bribie Island HF radar array (27°S, 153° E) can be set up to make angle of arrival and Doppler shift measurements throughout the range of spread-E_s, layers. Results of this experiment show that the range spread seen on ionograms is not due to multiple reflection with varying obliquity, but rather a genuine height spread exists. Where velocity measurements can be reliably made, reflector velocity appears to be a slowly varying function of height. Spread-E_s, can be blanketing or non-blanketing, sequential or non-sequential and at first impression it seems that the chief difference between spread-E_s, and normal E_s, is a small scale, partially transparent structure in lower regions that allows higher regions to be observed. It is suggested that on occasion spread-E_s, irregularities are further modulated by the passage of gravity waves.     

Mephisto

This article explores the resonances of objects that travelled between continents and the entangled imaginaries tied to them – here a 30-tonne German military tank captured by Australian soldiers during the First World War in France and shipped to Brisbane to be exhibited at the Queensland Museum. The author ‘reads’ the tank, intriguingly named ‘Mephisto’, as the apotheosis of nature/culture divide entrenched in nineteenth-century colonialism, which exported the taxonomies of the Enlightenment to the antipodes and in return repatriated objects of flora and fauna all over Europe. Mephisto thus also marks the manifestation of a German–Australian modernity: developed from the agricultural tractor, the tank remains a brutal and clumsy device designed purely to subdue and conquer territory.     

Transgender migrations: prostitution,identity and notions of ‘home’ in contemporary France

ABSTRACT

Migrant street prostitution in France has increased since the 1990s, largely as a result of the ease of movement facilitated by political shifts in Eastern Europe opening up national borders and the arrival of greater numbers of prostitutes from Africa and China. These often precarious migrations have generally been made by cisgender females; although, a comparatively smaller (but progressively significant) number are transgender. The representation of this latter group is explored in this article through four documentary/docufiction films that respectively recount what can be described as the sequential stages of geographical mobility (i.e. pre-migration, migration, and post-migration). Motivated by the concern that more particular voices within the ‘queer community’ are insufficiently represented, the focus here will be on how this group of transgender migrant prostitutes articulate a sense of ‘home’. Analysis is framed through Sara Ahmed’s notion of ‘home’ as ‘skin’, a porous space that blends the static and the mobile, the ‘here’ and ‘there’. The selected texts disarticulate the epistemology of prostitution in gendered terms and dislocate the transgender body from material associations that link successful migration with the movement from one place and body to another.     

The amplitude of auroral backscatter—III. Effect of tilted ionospheric layer

The effect of tilting of the E-layer on auroral backscatter is considered for the conditions applying in the vicinity of an auroral arc. Tilting modifies the degree of refraction, sometimes causing internal reflection, and this can explain a number of previously anomalous phenomena observed in auroral backscatter, including strong backscatter at apparently large aspect angles. As a result of tilts, refraction effects may be relevant over a wider range of frequencies than considered in the past, and the apparent aspect sensitivity and altitude of backscattered signals should be re-examined carefully.     

The latitudinal variation oi ionospheric absorption

The anomalous latitudinal variation, sometimes referred to as the equatorial anomaly, in ionospheric absorption observed by several investigators in the past is examined. For low dip angles (I ≤ 20°), the observed increases in absorption with increasing dip angles are due to the increasing contribution to the total absorption from the ionospheric region where the quasi-tranverse conditions hold. For dip angles greater than ∼- 20°, the major contribution to the total absorption comes from the ionospheric region satisfying the quasi-longitudinal conditions resulting in a decrease of absorption with increasing dip angles.     

Thermal range of coastal tourism resort microclimates

With considerable evidence demonstrating the intrinsic importance of weather and climate for tourist decision-making, the projected redistribution of climatic resources as a result of climate change is anticipated to have important consequences for temporal and spatial patterns of tourism demand. Some of the world's leading coastal tourism destinations (Mediterranean and Caribbean) have been identified as becoming ‘too hot’ for tourism. However, the microclimates of coastal tourism areas have not been considered by such assessments. With a focus on thermo-physiologically relevant climatic parameters, this paper examines the adaptive range of microclimatic conditions available in two coastal resort settings in the Caribbean islands of Barbados and Tobago. Recorded weather parameters include air temperature, black globe temperature, relative humidity, and wind speed. The microclimatic results, which are presented using the Universal Thermal Climate Index (UTCI), show that hourly thermal conditions can range up to 4 °C in different outdoor areas of the resort property (beach, garden, pool, cabana). This is salient in terms of characterizing tourism destinations for climate change assessments, as the results reveal that thermal conditions can vary at the micro-scale of a coastal resort, with the ability for tourists to attain thermally comfortable conditions within a single resort property. When a location becomes thermally uncomfortable (i.e. too hot), tourists can change their location (e.g. move from the pool to the beach), providing an onsite adaptive range between 1 °C and 4 °C. The results also demonstrate that thermo-physiologically relevant climatic parameters provide a more precise estimate of the available range of thermal comfort than is inferred from ambient temperature alone. The findings are discussed in the context of tourists’ climatic preferences and reveal that the microclimatic conditions recorded in this study (UTCI 29–36 °C) are well within tourists’ preferred thermal conditions and do not exceed tourists’ thermal thresholds for coastal tourism.     

Connected feminists: foregrounding the interpersonal in connective action

New social movement theories have been developed to address the organisational structures of activism in the age of digital platforms, but have tended to focus on structural questions rather than interpersonal dynamics. This paper engages with Bennett and Segerberg’s theory of connective action but uses a feminist lens to foreground the interpersonal dynamics between digitally equipped activists to develop a uniquely feminist account of connective action. It draws on Jo Freeman’s ‘tyranny of structurelessness’ to illustrate how informal organisation pervades new forms of connective action and continues to hamper the feminist movement. However, it also introduces and identifies the ‘feminist manager’ as an attempt to address the problematic practices of structurelessness and informality, and paves the way for consciously recognising the organisational structures required to advance the movement beyond consciousness-raising initiatives.     

Anthropological and physicochemical investigation of the burnt remains of Tomb IX in the ‘Sa Figu’ hypogeal necropolis (Sassari,Italy) – Early Bronze Age

Excavations carried out in Tomb IX of the hypogeic necropolis of ‘Sa Figu’, near the village of Ittiri (Sassari, Italy), supplied burnt human bone remains and pottery unambiguously referred to the Early Bronze Age (characterised by the local culture of ‘Bonnannaro’). Besides the anthropological study, we have investigated and evaluated the possibility of a funerary cremation practice in Sardinian pre‐history, a subject that has previously not been considered from a scientific point of view. Making use of a calibration procedure based on X‐ray diffraction (XRD) line‐broadening analysis, related to the microstructural properties, it was possible to estimate the combustion temperature to which the fragmented bones were subjected. It was found that the studied bones reached temperatures varying from 400°C up to a maximum of 850°C. This spread of values suggested inhomogeneous combustion of the bones, which seems compatible with funerary cremation practices. Copyright © 2007 John Wiley & Sons, Ltd.     

Optical interferometer measurements of thermospheric temperature at Kavalur (12.5°N, 78.5°E), India

First results on the behaviour of thermospheric temperature over Kavalur (12.5°N, 78.5°E geographic; 2.8°N geomagnetic latitude) located close to the geomagnetic equator in the Indian zone are presented. The results are based on measurements of the Doppler width of O(¹D) night airglow emission at 630 nm made with a pressure-scanned Fabry-Perot interferometer (FPI) on 16 nights during March April 1992. The average nighttime (2130-0430 IST) thermospheric temperature is found to be consistently higher than the MSIS-86 predictions on all but one of the nights. The mean difference between the observed nightly temperatures and model values is 269 K with a standard error of 91 K. On one of the nights (9/10 April 1992, Ap = 6) the temperature is found to increase by ~250 K around 2330 IST and is accompanied by a ‘midnight collapse’ of the F-region over Ahmedabad (23°N, 72°E, dip 26.3°N). This relationship between the temperature increase at Kavalur and F-region height decrease at Ahmedabad is also seen in the average behaviour of the two parameters. The temperature enhancement at Kavalur is interpreted as the signature of the equatorial midnight temperature maximum (MTM) and the descent of the F-region over Ahmedabad as the effect of the poleward neutral winds associated with the MTM.     

Another Look at Lerna: An EH IIB Trading Post?

The Early Helladic IIB sealings from Lerna have rarely been considered as functional documents even though they are often called as evidence for EH II economic complexity, for elite control of resources or even for ‘central place’ redistribution. Close analysis of the sealings, however, casts doubt on whether the documents support these economic or social interpretations, seeming rather to point to the grafting of a foreign system of resource management onto a less developed society. After examining the specific functions of the sealings —‘who did what?’— we consider their implications for social organization. This evidence is then linked to the wider picture: a whole range of new sealing practices as well as the striking innovations in architecture and construction which appear at much the same time. We conclude that these developments are largely due to the arrival of foreign (probably Anatolian) traders at Lerna early in EH IIB.     

Analysis of Es traces from a calibrated oblique ionosonde

An analysis is performed on ionosonde data produced during five years of operation of an oblique sounder transmitting on a path from Darwin (12.4°S, 130.9°E) to Alice Springs (23.5°S, 133.7°E). It is found that the occurrence of sporadic-E (E_s) shows a relatively mild diurnal dependence, with a significant amount of E_s occurring in the early evening before midnight. It appears that, on average, nighttime E_s produces weaker reflections than daytime E_s.The power of the E_s reflections as a function of frequency is collated for all ionograms. The resulting power curve exhibits total and partial reflection sections. In trying to reproduce the partial reflection section of the curve it is shown that a layer without horizontal structure is required to be only 100 m thick. A second model involving a layer consisting of horizontally localised clouds of scatterers, with scale sizes ranging from 100 to 1000 metres, reproduces the partial reflection section of the curve quite well. The size, intensity and distribution of the clouds affects the curve shape on individual ionograms, resulting in the suggestion that nighttime layers are more irregular than daytime layers.     

‘The women's lobby’: Networks,coalition building and the women of middle Australia

The ‘women's lobby’ or the ‘powerful feminist lobby’ has been held responsible for a range of evils including the undermining of the traditional family, public expenditure on community services, social engineering and the imposition of ‘political correctness’. To what extent is there a ‘women's lobby’ working from inside or outside government to influence public decision‐mating? In this paper we explore this question, using data from a social network analysis of the Australian women's movement conducted in 1992–3.

Our findings are that there is a large, very loosely connected network of organisations engaging in advocacy on behalf of women. Density of ties is less than is found in a comparable study of the Canadian women's movement but there are more ties between non‐government groups and government agencies. Issues of organisational philosophy have inhibited the development of a ‘peak body’ for the non‐government women's movement and led to reliance on issue‐specific coalitions. Latterly, awareness of increasing fragmentation has led to a series of attempts to create more effective national networking.     

Types of ionospheric scintillations in southern mid-latitudes during the last sunspot maximum

A 5-yr study (1987–1992) has been undertaken at a southern mid-latitude station, Brisbane (35.6°S invariant latitude) on scintillation occurrences in radio-satellite transmission (at a frequency of 150 MHz) from polar orbit Transit satellites, within a sub-ionospheric invariant latitude range 20–55°S. Over 7000 recorded passes were used to define the spatial and temporal occurrence pattern of different types of scintillation events. Two predominant scintillation types were found: so-called type P (associated with a scintillation patch close to the magnetic zenith) and type S (characteristic of the equatorward edge of auroral scintillation oval). Type S was by far the most frequent during sunspot maximum (1988–1992), with sharp occurrence peaks in the summer-autumn period. Its seasonal occurrence showed a high degree of correlation (correlation coefficient r = 0.8) with the seasonally averaged 10.7 cm solar radio flux. This type occurred mainly at night-time except in austral summer where 40% of scintillations were detected in daytime, coinciding with the well-known summer peak of sporadic-E occurrence. Type P was more predominant during a year (1987) of ascending sunspot activity but decreased to a much lower level during the sunspot maximum.     

Loss cone fluxes and pitch angle diffusion at the equatorial plane during auroral radio absorption events

The flux and pitch angle distribution of energetic electrons near the loss cone have been investigated over the energy range 15–300 keV, using measurements on the geosynchronous satellite GEOS-2 at the times of auroral radio absorption events detected by riometers in Scandinavia. It is shown that conditions of strong pitch angle diffusion apply only during the most intense absorption events ( 6 dB at 30 MHz) which are relatively infrequent. During most events the loss cone is partially depleted, with the degree of depletion increasing as the absorption becomes weaker. The variation of the pitch angle diffusion coefficient with the observed radio absorption is estimated. A consequence of loss cone depletion is a tendency to overestimate the smaller events when computing the radio absorption from flux measurements in the 0°–5° range of detector pointing angles. An empirical law is derived which enables the computation of radio absorption consistent with measurements. D-region recombination laws are discussed and limits are set on the height profile of the effective recombination coefficient.