56 research outputs found
Investigation of initiation of gigantic jets connecting thunderclouds to the ionosphere
The initiation of giant electrical discharges called as "gigantic jets"
connecting thunderclouds to the ionosphere is investigated by numerical
simulation method in this paper. Using similarity relations, the triggering
conditions of streamer formation in laboratory situations are extended to form
a criterion of initiation of gigantic jets. The energy source causing a
gigantic jet is considered due to the quasi-electrostatic field generated by
thunderclouds. The electron dynamics from ionization threshold to streamer
initiation are simulated by the Monte Carlo technique. It is found that
gigantic jets are initiated at a height of ~18-24 km. This is in agreement with
the observations. The method presented in this paper could be also applied to
the analysis of the initiation of other discharges such as blue jets and red
sprites.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France
Relationship between well-being and recycling rates: evidence from life satisfaction approach in Britain
This study explores the relationship between self-reported well-being and recycling rates. The estimates are based on Britain using data from the British Household Panel Survey. The effects of recycling rates on individuals' happiness are estimated. Two approaches are followed. The first approach refers to panel probit-ordinary least squares (OLS). The second approach is the latent class generalised ordered probit. The results support that a significant positive relationship between self-reported well-being and recycling is presented
Understanding the (non-)Use of Societal Wellbeing Indicators in National Policy Development : What Can We Learn from Civil Servants? A UK Case Study
Gross Domestic Product is often used as a proxy for societal well-being in the context of policy development. Its shortcomings in this context are, however, well documented, and numerous alternative indicator sets have been developed. Despite this, there is limited evidence of widespread use of these alternative indicator sets by people working in policy areas relevant to societal wellbeing. Civil servants are an important group of indicator end-users. Better understanding their views concerning measuring societal wellbeing can support wider discussions about what factors determine indicator use and influence in policy decision-making. Taking the UK as a case study, we ask what views exist among civil servants in the UK about measuring societal well-being? To answer this question, we used a bootstrapped Q methodology, interviewing 20 civil servants to elicit their views about measuring societal well-being. Three distinct discourses emerged from our analysis: one that was concerned about the consequences of ignoring natural, social and human capital in decision making; one that emphasised opportunity and autonomy as key determinants of well-being; and one that focused on the technical aspects of measuring societal well-being. Each of these discourses has direct implications for the way that we integrate societal wellbeing into policy making and highlights the potential benefits of including end-users in indicator development and strategy
Observations of Prolific Transient Luminous Event Production Above a Mesoscale Convective System in Argentina During the Sprite2006 Campaign in Brazil
On the night of 22â23 February 2006, 444 transient luminous events (TLEs), 86% sprites, were observed above a prolific mesoscale convective system (MCS) over Argentina, as part of the third sprite campaign in Brazil. GOES infrared (IR) cloud top temperatures (Tc) and Tropical Rainfall Measuring Mission (TRMM) radar (PR) and microwave (TMI) data were used to investigate the MCS convective characteristics and their relationship with World Wide Location Network (WWLLN) detected cloudâtoâground (CG) lightning and TLE activity. The MCS had a minimum lifetime of 20 hours, 8.5 as a MCS, a maximum extent of âŒ430,000 km2, and gusty winds of âŒ39â50 km/h. It had several distinctive characteristics: exceptionally high TLE rate, multicellular structure with 19 distinguishable convective regions, and cloud tops temperatures (Tc) âŒ10â20 °C higher than regular TLEproducing MCSs over the central USA and South America. Most TLEs occurred above âindividual stratiform regionsâ, where Tc varied from â45 °C to â53 °C from the beginning to the end of the night, surrounding the areas of strong convections, with convective cores at Tc â59 °C to â74 °C, which did not extend up to or overshoot the tropopause, estimated at â75 °C (âŒ17.1 km) as normally observed for TLEâproducing MCS in these regions. The moderated convection is contrary to the expectation that large charge production is accompanied by vigorous updrafts within deep convection that give rise to cold cloud overshooting tops, thus prompting a detailed study of this prolific TLEâproducing thunderstorm. On the basis of a charge moment change threshold of 350 Ckm and estimated 5 km charge removal altitude, a lower threshold of âŒ4,300 C/h was estimated for the hourly charge transfer rate necessary for the observed sprite production (383 events), which is twice the rate for an average TLEâproducingMCS (70 events), also estimated.TMI/TRMM data for the storm at early development showed a low brightness temperature of 84 K, indicative of significant ice content, which is important for cloud electrification processes. We suggest that the unusually high incidence of TLEs in this moderately convective MCS may be related to other local geophysical phenomena such as a large tropospheric aerosol concentration due to smoke from forest fires. Satellite fire count data showed that there were âŒ200 fires between 20 and 22 February immediately north of the MCS initiation region and a transport simulation with the Coupled AerosolâTracer Transport model from the Brazilian developments on Regional Atmospheric Modeling System (CATT/BRAMS) model showed a large PM2.5 aerosol concentration, 10,000 mg/m2 (column integrated), at the region where the MCS developed. The aerosols present in the smoke may have been a source of ice nuclei affecting the production of ice particles that get positively charged, accounting for the charge transfer rate necessary to originate the observed TLE production
- âŠ