Observations of quiet-time moderate midlatitude L-band scintillation in association with plasma bubbles

Observations of moderate night time amplitude scintillation on the GPS L1C/A signal were recorded at the midlatitude station of Nicosia, corresponding geographic latitude and longitude of 35.18˚N and 33.38˚E respectively, on a geomagnetically quiet day. The variations of slant total electron content (STEC) and amplitude scintillation index (S4) on the night of June 12, 2014, indicate the presence of electron density depletions accompanying scintillation occurrence. The estimated apparent horizontal drift velocity and propagation direction of the plasma depletions are consistent with those observed for the equatorial plasma bubbles, thus suggesting that the moderate amplitude L-band scintillation observed over Nicosia may be associated with the extension of such plasma bubbles. The L-band scintillation occurrence was concurrent with the observations of range spread F on the ionograms recorded by the digisonde at Nicosia. The height–time–intensity plot generated using the ionogram data also showed features which can be attributed to off-angle reflections from electron density depletions, thus corroborating the STEC observations. This observation suggests that the midlatitude ionosphere is more active even during geomagnetically quiet days than previously thought and that further studies are necessary. This is particularly relevant for the GNSS user community and related applications

Determination of the hemispheric character (i.e. southern or northern latitudinal position) of equatorial ionosonde stations as deduced from long-term recordings of the minimum height of the F-region (h ' F)

The virtual (or minimum) height of the F-region (h'F), recorded over a number of solar cycles for I I equatorial and mid-latitude ionosonde stations, was used to deduce the hemispheric (i.e. southern or northern hemisphere) character of equatorial stations. The semi-annual median monthly height (h'F) variations consist of two components: major local summer maximum and winter sub-maximum (about 5 percent of the summer maximum). This hemispheric pattern was most consistently observed for equatorial stations (within 5degrees of the geomagnetic equator) in a period centred on the local midnight (21-03 LT) but was also present, to a lesser extent, at mid-latitude stations and at other time intervals. It is evident that the physical parameter h'F defines the hemispheric character of an equatorial station which has different (sometimes opposite) geographic and geomagnetic latitudes. There is a sharp transition in the latitudinal character of the stations on both sides of the equator leading to hypothesis that the equal maxima in h'F in December and June solstices are observed at a near-equator position labelled as ionosonde deduced equator (IDE). Such a signature was observed for an American equatorial (both geographic and geomagnetic) station Talara (Peru) which is an experimental support of the hypothesis. The IDE can be another useful parameter characterising the equatorial ionosphere. This finding reveals a new application of the standard ionosonde data in defining the geophysical character of equatorial stations, being an important contribution to space climatology. (C) 2002 Elsevier Science Ltd. All rights reserved

‘Great markers of culture’: The Australian sport field

In Creative Nation, sport is distinguished by its almost complete absence, except as a competitor for sponsorship with ‘cultural organisations’, and in brief mentions as content for SBS Radio and Aboriginal community radio stations. Sport is not mentioned at all in the 2011 National Cultural Policy Discussion Paper, but in the ensuing policy, Creative Australia, is treated, with art and religion, as one of the ‘great markers of culture’ in which, distinctively, elite professionalism, amateurism and fandom/appreciation happily co-exist. This article reflects on developments in the Australian sport field over the last two decades, highlighting the management of elite-grass roots and public–private funding tensions, and relevant parallels in the arts field. It addresses the pivotal relationship between the sport and broadcast media fields, arguing that sport, as a Bourdieusian ‘field of struggles’, is an under-appreciated domain of national cultural policy in which different forms of capital collide and converge

Mainstreaming Sustainable Decision-making for Ecosystems: Integrating Ecological and Socio-economic Targets within a Decision Support System

The authors acknowledge the publisher in granting permission for making post-print version available in open access institutional repository.Ecosystem sustainable management, and the underlying decision-making process, generally requires the analysis of ecological, social and economic information, integrating both value judgements and policy goals. Since this process can be regarded as complex and tricky, natural resource management requires a well-structured and transparent decision-making process. In this regard, it is necessary to search for and implement sets of measures which can effectively solve emerging problems. Based on the assumption that decisions concerning the management of watersheds may imply trade-offs between their different functions, the intent was to test if software tools, such as MULINO, could be used to enhance multi-level governance of ecosystems. To achieve this, the DPSIR and MCA were incorporated, to analyze and quantify the explicit trade-offs between several types of services provided by estuarine ecosystems and stakeholder objectives. The Mondego Estuary (Portugal) was used as case study. This system is under constant pressure, from both natural and anthropogenic drivers. Urban expansion and tourism were identified as having a strong impact on system development, while agriculture, although declining, had a determinant role in the system’s status. The study evaluated potential alternatives focusing on the water quality improvement goals that could be designed for the system. The MCA ranked several alternatives and pinpointed as the ʺbestʺ option the alternative that combines buffer zones, eco-tourism enhancement, wastewater treatment plant development, the Murraceira trademark and bivalves bio-control. This analysis allowed a simplification of several management objectives; nonetheless, further tests are still required to understand the real connection between these outcomes and decision-makers

Ionospheric Response to Natural and Man Made Impacts

International audienceThe problem of energy transfer from the Earth’s solid mantles to the atmosphere and surrounding space is of essential importance for the fundamental geophysics and applied studies. These processes can largely govern the structure and dynamics of the phenomena developing in the near Earth space. Moreover, the consequences of such impacts as earthquakes, hurricanes, etc. upon the Earth’s electromagnetic field and ionosphere can become an extra factor in monitoring the processes involved in the upcoming large-scale seismic and meteorological catastrophes. The acoustic-gravity waves (comprising acoustic and gravity waves and hereafter referred to as AGW) are one of the most efficient ways to transport over the ionosphere the energy of the dynamic processes developing in the low atmosphere. The early experiments of the 1950’s and 60’s on Doppler sounding even showed that the ionosphere can serve as a sensitive indicator of natural and man made disturbances. The Doppler sounding of the ionosphere revealed impulse and wave disturbances excited by powerful sources of infrasound, such as: a) megaton nuclear explosions in the atmosphere, kiloton ground industrial explosions, b) earthquakes and volcano eruptions, c) thunderstorms, tornadoes and tsunamis, d) bolides and meteorites, e) rocket launches and flights of supersonicjets, f) aurora and solar eclipse