Causes of plasma flow bursts and dayside auroral transients: An evaluation of two models Invoking reconnection pulses and changes in the Y component of the magnetosheath field

Longitudinal flow bursts observed by the European Incoherent Scatter (EISCAT) radar, in association with dayside auroral transients observed from Svalbard, have been interpreted as resulting from pulses of enhanced reconnection at the dayside magnetopause. However, an alternative model has recently been proposed for a steady rate of magnetopause reconnection, in which the bursts of longitudinal flow are due to increases in the field line curvature force, associated with the By component of the magnetosheath field. We here evaluate these two models, using observations on January 20, 1990, by EISCAT and a 630-nm all-sky camera at Ny Ålesund. For both models, we predict the behavior of both the dayside flows and the 630-nm emissions on newly opened field lines. It is shown that the signatures of steady reconnection and magnetosheath By changes could possibly resemble the observed 630-nm auroral events, but only for certain locations of the observing site, relative to the ionospheric projection of the reconnection X line: however, in such cases, the flow bursts would be seen between the 630-nm transients and not within them. On the other hand, the model of reconnection rate pulses predicts that the flows will be enhanced within each 630-nm transient auroral event. The observations on January 20, 1990, are shown to be consistent with the model of enhanced reconnection rate pulses over a background level and inconsistent with the effects of periodic enhancements of the magnitude of the magnetosheath By component. We estimate that the reconnection rate within the pulses would have to be at least an order of magnitude larger than the background level between the pulses.

Modelling the high-latitude ionosphere for time-varying plasma convection

The paper discusses how variations in the pattern of convective plasma flows should beincluded in self-consistent time-dependent models of the coupled ionosphere-thermosphere system. The author shows how these variations depend upon the mechanism by which the solar wind flow excites the convection. The modelling of these effects is not just of relevance to the polar ionosphere. This is because the influence of convection is not confined to high latitudes: the resultant heating and composition changes in the thermosphere are communicated to lower latitudes by the winds which are also greatly modified by the plasma convection. These thermospheric changes alter the global distribution of plasma by modulatingthe rates of the chemical reactions which areresponsible for the loss of plasma. Hence the modelling of these high-latitude processes is of relevanceto the design and operation of HF communication, radar and navigation systems worldwide.

EISCAT observations of bursts of rapid flow in the high latitude dayside ionosphere

Observations are presented of short-lived, highly structured bursts of rapid plasma flow observed with the EISCAT radar in the high latitude dayside ionosphere. It is shown that the properties of the bursts are consistent with ionospheric perturbations caused by impulsive, localized reconnection at the Earth's magnetopause, i.e. by flux transfer events.

The DYMECS project: a statistical approach for the evaluation of convective storms in high-resolution NWP models

A new frontier in weather forecasting is emerging by operational forecast models now being run at convection-permitting resolutions at many national weather services. However, this is not a panacea; significant systematic errors remain in the character of convective storms and rainfall distributions. The DYMECS project (Dynamical and Microphysical Evolution of Convective Storms) is taking a fundamentally new approach to evaluate and improve such models: rather than relying on a limited number of cases, which may not be representative, we have gathered a large database of 3D storm structures on 40 convective days using the Chilbolton radar in southern England. We have related these structures to storm life-cycles derived by tracking features in the rainfall from the UK radar network, and compared them statistically to storm structures in the Met Office model, which we ran at horizontal grid length between 1.5 km and 100 m, including simulations with different subgrid mixing length. We also evaluated the scale and intensity of convective updrafts using a new radar technique. We find that the horizontal size of simulated convective storms and the updrafts within them is much too large at 1.5-km resolution, such that the convective mass flux of individual updrafts can be too large by an order of magnitude. The scale of precipitation cores and updrafts decreases steadily with decreasing grid lengths, as does the typical storm lifetime. The 200-m grid-length simulation with standard mixing length performs best over all diagnostics, although a greater mixing length improves the representation of deep convective storms.

An intelligent system to real time rainfall prediction using radar data

This work presents a new approach for rainfall measurements making use of weather radar data for real time application to the radar systems operated by institute of Meteorological Research (IPMET) - UNESP - Bauru - SP-Brazil. Several real time adjustment techniques has been presented being most of them based on surface rain-gauge network. However, some of these methods do not regard the effect of the integration area, time integration and distance rainfall-radar. In this paper, artificial neural networks have been applied for generate a radar reflectivity-rain relationships which regard all effects described above. To evaluate prediction procedure, cross validation was performed using data from IPMET weather Doppler radar and rain-gauge network under the radar umbrella. The preliminary results were acceptable for rainfalls prediction. The small errors observed result from the spatial density and the time resolution of the rain-gauges networks used to calibrate the radar.

Geoestatística aplicada à acumulação da precipitação pluviométrica com radar meteorológico

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Analisi di dati telerilevati ottici e radar per la gestione dei disastri: le alluvioni nel Bangladesh.

Abstract L’utilizzo dei dati satellitari per la gestione dei disastri naturali è fondamentale nei paesi in via di sviluppo, dove raramente esiste un censimento ed è difficile per i governi aggiornare le proprie banche dati con le tecniche di rilevamento e metodi di mappatura tradizionali che sono entrambe lunghe e onerose. A supporto dell’importanza dell’impiego del telerilevamento e per favorirne l’uso nel caso di catastrofi, vi è l’operato di diverse organizzazioni internazionali promosse da enti di ricerca, da agenzie governative o da organismi sopranazionali, le quali svolgono un lavoro di cruciale valore, fornendo sostegno tecnico a chi si occupa di far giungere alle popolazioni colpite gli aiuti umanitari e i soccorsi nel più breve tempo possibile. L’attività di tesi è nata proprio dalla collaborazione con una di esse, ITHACA (Information Technology for Humanitarian Assistance, Cooperation and Action), organizzazione no-profit, fondata dal Politecnico di Torino e SiTI (Istituto Superiore sui Sistemi Territoriali per l’Innovazione), la quale a sua volta collabora con il WFP (World Food Programme) delle Nazioni Unite, realizzando cartografie speditive necessarie per la valutazione delle conseguenze di un evento catastrofico, attraverso l’impiego di dati acquisiti da satellite. Su questo tema si è inserito il presente lavoro che ha come obiettivo quello di dimostrare la valenza dei dati telerilevati, siano essi di tipo ottico o Radar, nel caso di alcuni dei disastri naturali più catastrofici, le alluvioni. In particolare è stata studiata la vulnerabilità del Bangladesh, il quale annualmente si trova ad affrontare eventi alluvionali, spesso di grave intensità. Preliminarmente allo studio, è stata condotta una ricerca bibliografica al fine di avere una buona conoscenza dell’area sia in termini geografici e fisici che di sviluppo e tipologia di urbanizzazione. E’stata indagata in particolare l’alluvione che ha colpito il paese nel Luglio del 2004, attraverso delle immagini satellitari multispettrali, in particolare Landsat 7, per un inquadramento pre-evento, ed ASTER per studiare la situazione a distanza di tre mesi dall’accaduto (immagine rilevata il 20 Ottobre 2004). Su tali immagini sono state condotte delle classificazioni supervisionate con il metodo della massima verosimiglianza che hanno portato la suddivisione del territorio in quattro classi di destinazione d’uso del suolo: urbano (Build-up), campi e vegetazione (Crops&Vegetation), sabbia e scavi (Sand&Excavation), idrografia e zone alluvionate (Water). Dalla sperimentazione è emerso come tali immagini multispettrali si prestino molto bene per l’analisi delle differenti caratteristiche del territorio, difatti la validazione condotta sulla mappa tematica derivata dall’immagine Landsat 7 ha portato ad un’accuratezza del 93% circa, mentre la validazione dell’immagine ASTER è stata solo di tipo qualitativo, in quanto, considerata l’entità della situazione rilevata, non è stato possibile avere un confronto con dei punti da assumere come verità a terra. Un’interpretazione della mappa tematica derivante dalla classificazione dell’immagine ASTER è stata elaborata incrociandola in ambiente GIS con dati forniti dal CEGIS (Center for Environmental and Geographic Information Services) riguardanti il landuse della zona in esame; da ciò è emerso che le zone destinate alla coltivazione del riso sono più vulnerabili alle inondazioni ed in particolare nell’Ottobre 2004 il 95% delle aree esondate ha interessato tali colture. Le immagini ottiche presentano un grosso limite nel caso delle alluvioni: la rilevante copertura nuvolosa che spesso accompagna siffatti eventi impedisce ai sensori satellitari operanti nel campo dell’ottico di rilevare il territorio, e per questo di frequente essi non si prestano ad essere impiegati per un’indagine nella fase di prima emergenza. In questa circostanza, un valido aiuto giunge dall’impiego di immagini Radar, le quali permettono osservazioni ad ogni ora del giorno e della notte, anche in presenza di nuvole, rendendole di fondamentale importanza nelle situazioni descritte. Per dimostrare la validità di questi sensori si sono analizzati due subset derivanti da un mosaico di immagini della nuova costellazione italiana ad alta risoluzione CosmoSkymed: il primo va dalla città di Dhaka al Golfo del Bengala ed il secondo copre la zona più a Nord nel distretto di Sylhet. Dalla sperimentazione condotta su tali immagini radar, che ha comportato come ovvio problematiche del tutto differenti rispetto alle elaborazioni tradizionalmente condotte su immagini nel campo dell’ottico, si è potuto verificare come l’estrazione dei corpi d’acqua e più in generale dell’idrografia risulti valida e di veloce computazione. Sono emersi tuttavia dei problemi, per esempio per quanto riguarda la classificazione dell’acqua in presenza di rilievi montuosi; tali complicazioni sono dovute alla presenza di zone d’ombra che risultano erroneamente assegnate alla classe water, ma è stato possibile correggere tali errori di attribuzione mascherando i rilievi con l’ausilio di una mappa delle pendenze ricavata da modelli di elevazione SRTM (Shuttle Radar Topographic Mission). La validazione dei risultati della classificazione, condotta con un grande numero di check points, ha fornito risultati molto incoraggianti (ca. 90%). Nonostante le problematiche riscontrate, il Radar, in sé o in accoppiamento con altri dati di diversa origine, si presta dunque a fornire in breve tempo informazioni sull’estensione dell’esondazione, sul grado di devastazione, sulle caratteristiche delle aree esondate, sulle vie di fuga più adatte, diventando un’importante risorsa per chi si occupa di gestire l’emergenza in caso di eventi calamitosi. L’integrazione con i dati di tipo ottico è inoltre essenziale per pervenire ad una migliore caratterizzazione del fenomeno, sia in termini di change detection che di monitoraggio post-evento.

Funding the utilization of community health workers in Texas

Community health workers (CHWs) are volunteers or paid members of communities that perform outreach, patient assistance, health education, and assist in navigation of healthcare system amongst other duties. The utilization of CHWs in hospital and community setting provides health benefits to their communities while reducing cost to the overall healthcare system. ^ The general population of Texas lacks adequate access to primary care. An important indicator of such a crisis is excessive usage of emergency department services in Texas, especially by the large minority population within the state. Also, unmanaged chronic diseases have been shown to be correlated with the excessive usage of emergency services. According to a recent survey of 25 Houston metropolitan area hospitals, almost 54% of the ER visits could have been resolved in primary care settings. A Galveston based study also indicated that the ER usage was higher amongst African-Americans and Latinos. Meanwhile, 28.5% of the total ER visits were made by Latinos from the surrounding areas (Begley et al., 2007). There is substantial evidence present which indicates enormous cost-savings that CHWs have produced in Texas and nationwide through reduction in unnecessary ER visits along with better management of chronic diseases (Fedder et al, 2003). ^ This paper provides an analysis regarding the need and importance for sustainable and stable sources of funding for Community health workers (CHWs) in Texas utilizing Kingdon's model of Agenda Setting as framework. The policy analysis is also aimed at reporting on the policy process and actions taken by Children at Risk to address this critical issue. Children at Risk, a Houston based advocacy organization, has created a legislative proposal that calls on the Texas Health and Human Commission to apply for a Medicaid §§1115 waiver to provide sustainable sources of funding for CHWs, Rep. John Zerwas sponsored HB 2244 bill and it was filed on March 3, 2011. The bill would affect the use of CHWs in Texas in two ways: 1) through the establishment and operation of a program designed to train and educate CHWs 2) by creating a statewide training and certification advisory committee. The advisory committee is required in the bill to submit recommendations for providing sustainable funding and employment for CHWs. The HB 2244 failed to move out of the House Public Health committee. However, HB2244 was amended into HB 2610 introduced by Representative Guillen. The House Bill 2610 is geared towards establishing a community-based navigator program in order to assist individuals applying for public assistance through the Internet. The House Bill 2610 was signed by the Governor and will be effective September 1, 2011.^

Radar en la tormenta : la problemática de la selección de textos literarios infantiles

Fil: Pujalde Ibarra, Carmen Patricia. Universidad Nacional del Nordeste

Aplicación práctica transceptor BGT24MTR11 : radar Doppler

En los últimos tiempos, los radares han dejado de ser instrumentos utilizados únicamente en aviación, defensa y detección de velocidad. El avance de la tecnología de radiofrecuencia ha permitido la reducción de coste, tamaño y consumo de los componentes radar. Esto ha permitido que cada sea más frecuente el uso del radar en elementos de nuestra vida cotidiana tales como la automoción, la seguridad, la medida de líquidos… Este proyecto se basa en uno de estos nuevos componentes de bajo coste y pequeño tamaño, el transceptor BGT24MTR11. El BGTR24MTR11 integra transmisor, VCO y receptor, los elementos principales para la creación de un radar Doppler en la banda de frecuencia ISM 24-24,25 GHz. A partir de la placa de evaluación de ese transceptor, se aborda el diseño de un prototipo/demostrador de radar Doppler CW en la banda de 24 GHz. Para la generación de frecuencia se utiliza la placa de evaluación del PLL HMC702 y se ha diseñado un PCB a medida cuyas funciones son las de alimentación, programación y amplificación de las señales recibidas por el prototipo. Por último, se comprueba el correcto funcionamiento del prototipo y se verifica su funcionamiento mediante la simulación de dos escenarios de prueba. ABSTRACT. In the recent times, radar systems have changed of being tools used only in aviation, defence and speed detection. Radiofrequency technology improvements have allowed a cost, size and power consumption of the radar components. This is the reason because each time is more frequent the use of radar in elements of our daily life such as automotive, security, liquid measurements… This Project is base don one of this low power and size components, the MMIC transceptor BGT24MTR11. This transceptor integrates the main components needed to make a Doppler radar in the ISM Band (24-24 GHz), the transmitter, the receiver with the low noise amplifier and the VCO. Using the evaluation board of this transceptor, this Project approach the design of a CW Doppler radar prototype/demonstrator in the frequency band of 24 GHz. The frequency generation is based on the use of the HMC702 PLL evaluation board. Moreover, it has been designed a custom PCB whose funcionts are the power supply, programation and amplification of the signals received by the prototype. At the end, the correct operation of the prototype is verified and it is tested simulating two different test scenarios.

In situ investigation of rapid subsurface flow : Temporal dynamics and catchment-scale implication

Non peer reviewed

Department of Transportation national plan for navigation /

Issued Nov. 1977.

The effects of traffic radar guns on law enforcement officers : hearing before the Ad Hoc Subcommittee on Consumer and Environmental Issues of the Committee on Governmental Affairs, United States Senate, One Hundred Second Congress, second session, August 10, 1992.

Includes bibliographical references.

Coastal Ocean Dynamics Applications Radar (CODAR) remote sensing demonstration program /

Mode of access: Internet.

A system for using radar to record wave direction /

"September 1979."