Does the butterfly diagram indicate asolar flux-transport dynamo?

We address the question whether the properties of the observed latitude-time diagram of sunspot occurence (the butterfly diagram) provide evidence for the operation of a flux-transport dynamo, which explains the migration of the sunspot zones and the period of the solar cycle in terms of a deep equatorward meridional flow. We show that the properties of the butterfly diagram are equally well reproduced by a conventional dynamo model with migrating dynamo waves, but without transport of magnetic flux by a flow. These properties seem to be generic for an oscillatory and migratory field of dipole parity and thus do not permit an observational distinction between different dynamo approaches.Comment: 4 pages, 1 figur

Report of the Working Group on Determining the Child\u27s Capacity to Make Decisions

[Preamble] As with adults, a lawyer has an ethical obligation to advocate the position of a child unless independent evidence exists that the child is unable to express a reasoned choice about issues that are relevant to the particular purpose for which the lawyer is representing the child. Where such evidence exists, the lawyer must engage in additional fact-finding to determine whether the child has, or may develop, the capacity to direct the lawyer\u27s action in the particular context

Flow instabilities of magnetic flux tubes IV. Flux storage in the solar overshoot region

We consider the effects of material flows on the dynamics of toroidal magnetic flux tubes located close to the base of the solar convection zone, initially within the overshoot region. The problem is to find the physical conditions in which magnetic flux can be stored for periods comparable to the dynamo amplification time, which is of the order of a few years. We carry out nonlinear numerical simulations to investigate the stability and dynamics of thin flux tubes subject to perpendicular and longitudinal flows. We compare the simulations with the results of simplified analytical approximations. We determine ranges of the flow parameters for which a linearly Parker-stable magnetic flux tube is stored in the middle of the overshoot region for a period comparable to the dynamo amplification time. The residence time for magnetic flux tubes with fluxes of 2x10^{21} Mx in the convective overshoot layer is comparable to the dynamo amplification time, provided that the average speed and the duration of the downflow do not exceed about 50 m/s and 100 days, respectively, and that the lateral extension of the flow is smaller than about 10 degrees.Comment: Accepted to be published in Astronomy and Astrophysics. 16 pages, 16 figures. To access GIF animations, use http://www.mps.mpg.de/homes/ishik/flute/frict_inst.gif, http://www.mps.mpg.de/homes/ishik/flute/TF60.gif and http://www.mps.mpg.de/homes/ishik/flute/TF180.gi

El prólogo dedicado a Juan II de Vasco Ramírez de Guzmán: edición y estudio

Los manuscritos 9513, 9522 y 9358 de la Biblioteca Nacional\ud de España transmiten un prólogo de Vasco Ramírez de Guzmán a una traducción\ud desconocida y perdida dedicada al monarca Juan II de Castilla. La\ud mayor parte de la crítica ha considerado que este prólogo pertenecía a la\ud traducción de la versión latina del XII Diálogo de los muertos de Luciano.\ud En el presente trabajo, además de editar el prólogo y analizar su contenido,\ud se demuestra que se trata de un prólogo a una traducción perdida del De\ud consideratione de San Bernardo de Claraval.The Spanish National Library’s manuscripts 9513, 9522 and\ud 9358 transmit a Vasco Ramírez de Guzmán’s preface to an unknown and\ud lost translation devoted to the King John II of Castille. The majority of the\ud Literature Criticism have considered this preface to be part of the translation\ud into Latin of Lucian of Samosata’s XII Dialogue of the Dead. In this\ud article, in addition of editing and analysing the content of that preface, we\ud prove that it is in fact a foreword to a lost translation of Saint Bernard of\ud Clairvaux’s De consideratione

A coupled model of magnetic flux generation and transport in stars

We present a combined model for magnetic field generation and transport in cool stars with outer convection zones. The mean toroidal magnetic field, which is generated by a cyclic thin-layer alpha-omega dynamo at the bottom of the convection zone is taken to determine the emergence probability of magnetic flux tubes in the photosphere. Following the nonlinear rise of the unstable thin flux tubes, emergence latitudes and tilt angles of bipolar magnetic regions are determined. These quantities are put into a surface flux transport model, which simulates the surface evolution of magnetic flux under the effects of large-scale flows and turbulent diffusion. First results are discussed for the case of the Sun and for more rapidly rotating solar-type stars.Comment: Astron. Nachr. /AN, 328, 1111-1113 (2007). A newer, more extended paper related to this study can be reached here: http://arxiv.org/abs/1102.0569 (A&A 528, A135 [2011]). The supplementary animations can be reached here: http://www.aip.de/AN/movie

Los «errores» de una traducción medieval: la versión castellana de la Historia de septem sapientibus.

A partir de las discordancias observadas entre la versión castellana de la Historia de septeni sapientibus y su original, se establecen los diferentes tipos de «erron> que podemos encontrar en una traducción medieval

Técnicas de traducción en el siglo XV castellano: la novella de Diego de Cañizares a la luz de su or

El presente artículo es continuación y complemento de la edición de la novella de Diego de Cañizares y de su original latino que publiqué hace unos años en esta misma revista. Tras una consideración sobre los aspectos teóricos relacionados con la práctica de la traducción durante el siglo XV castellano, se analizan las técnicas traductológicas que emplea Diego de Cañizares para convertir en novella un exemplum homilético como era la Historia de septem sapientibus de Juan Gobi

La forma de gobierno en la Constitución de Cádiz (reflexiones sobre la configuración de la Jefatura del Estado monárquica)

Aunque el presente estudio ha de centrarse en la institución monárquica y su consideración en el constitucionalismo gaditano, resulta necesaria una previa reflexión que nos permitirá situarnos en el contexto histórico en que el texto constitucional se elabora; pues sólo así se comprende cómo se lleva a cabo la profunda reforma institucional en Cádiz introduciendo cambios tan revolucionarios como los franceses sin, en cambio, constituir un enfrentamiento con las instituciones establecidas internamente

Flux-dominated solar dynamo model with a thin shear layer

Flux-dominated solar dynamo models have demonstrated to reproduce the main features of the large scale solar magnetic cycle, however the use of a solar like differential rotation profile implies in the the formation of strong toroidal magnetic fields at high latitudes where they are not observed. In this work, we invoke the hypothesis of a thin-width tachocline in order to confine the high-latitude toroidal magnetic fields to a small area below the overshoot layer, thus avoiding its influence on a Babcock-Leighton type dynamo process. Our results favor a dynamo operating inside the convection zone with a tachocline that essentially works as a storage region when it coincides with the overshoot layer.Comment: 4 pages, 2 figures, accepted for publication in Astronomische Nachrichte