La llamada “Edad del Cobre” en el siglo XIX. Aportaciones de Casiano de Prado y Juan Vilanova y Piera

Las tres edades que Tito Lucrecio Caro (99-55 a.C.) había reconocido en la Antigüedad para las épocas anteriores: Edad de Piedra, Edad del Bronce y Edad del Hierro, fueron asumidas en la primera mitad del siglo XIX para clasificar los objetos prehistóricos, cuando aún esta disciplina no era reconocida oficialmente y escasos investigadores la practicaban. Pero, frente a una clasificación tan estática, basada en los datos que hacían referencia exclusivamente a aspectos técnicos, con el desarrollo de nuevas disciplinas como la Geología y la Paleontología, que aportaban criterios de sucesión estratigráfica, se empezaron a observar algunas anomalías. Y más aún, después de la irrupción del paradigma darwinista, a partir de 1859, y la comprobación al mismo tiempo de que podían existir momentos intermedios o de transición (evolución sin ruptura) en el desarrollo cultural. La aparición de objetos de cobre puro, por ejemplo, permitiría plantear la existencia de una Edad del Cobre, situada entre la Edad de Piedra y la Edad del Bronce. El reconocimiento de la Edad del Cobre fue algo muy lento y el debate sobre su existencia o no llegó hasta bien entrado el siglo XX. El presente artículo se centra en el estudio historiográfico sobre cómo se llegó a aceptar la Edad del Cobre, que fue uno de los grandes temas de discusión del siglo XIX, y que hoy está injustificadamente olvidado en la literatura científica especializada

Ingenieros de minas arqueólogos en el siglo XIX. La huella de Prado. Homenaje a Casiano de Prado (1797-1866) en el bicentenario de su nacimiento.

Con motivo del bicentenario del nacimiento de Casiano de Prado, los autores del trabajo hemos querido rendirle un homenaje con esta tabla cronológica, donde se observa la importancia que tuvieron los ingenieros de minas en la arqueología española, especialmente la prehistórica, durante el siglo XIX. En su tiempo, Prado fue el inductor y el más importante activista en pro de la Ciencia prehistórica, no sólo entre los ingenieros de minas, sino también en buena parte de la comunidad científica. Casiano de Prado, que estaba al tanto de las investigaciones que a este respecto se estaban realizando en Francia desde los años 50, especialmente las de Boucher de Perthes, marca los inicios de los estudios prehistóricos en España. Al principio, hace estas investigaciones de forma privada, y las divulga a partir de 1862 cuando descubre, conjuntamente con Luis Lartet y con Verneuil, un bifaz paleolítico en San Isidro. Con este hallazgo será España el tercer país en el mundo, tras Francia e Inglaterra, donde se reconozca la existencia del ser humano durante la prehistoria

Future Arctic sea-ice loss reduces severity of cold air outbreaks in midlatitudes

This is the final version of the article. Available from American Geophysical Union (AGU) via the DOI in this record.The effects of Arctic sea-ice loss on cold air outbreaks (CAOs) in midlatitudes remains unclear. Previous studies have defined CAOs relative to present-day climate, but changes in CAOs, defined in such a way, may reflect changes in mean climate and not in weather variability, and society is more sensitive to the latter. Here we revisit this topic but applying changing temperature thresholds relating to climate conditions of the time. CAOs do not change in frequency or duration in response to projected sea-ice loss. However, they become less severe, mainly due to advection of warmed polar air, since the dynamics associated with the occurrence of CAOs are largely not affected. CAOs weaken even in midlatitude regions where the winter-mean temperature decreases in response to Arctic sea-ice loss. These results are robustly simulated by two atmospheric models prescribed with differing future sea ice states and in transient runs where external forcings are included.This work was supported by the Natural Environment Research Council grants NE/M006123/1 and NE/J019585/1. The authors kindly thank Clara Deser, Lantao Sun and Bob Tomas for their efforts in performing the CAM4 simulations and for sharing these. We also thank Dr. Michael Kelleher for his aid with the code. The HadGAM2 simulations were performed on the ARCHER UK National Supercomputing Service. We acknowledge the World Climate Research Programme's Working Group on Coupled Modelling, which is responsible for CMIP5, and we thank the climate modeling groups for producing and making available their model output. Data from CMIP5 runs can be accessed through http://cmip-pcmdi.llnl.gov/cmip5/ and data from the sea ice experiments are available from the authors upon request

Sobre una carta de Casiano de Prado enviada a Fernández de Castro en mayo de 1865 desde París, donde se destaca la importancia de los estudios prehistóricos

La carta que en este trabajo estudiamos forma parte de correspondencia que se encontraba extraviada. De la importancia de su hallazgo nos da una idea el hecho de que la correspondencia de Casiano de Prado se encuentra extraviada y que podría darnos idea de la relación entre Prado y los prehistoriadores franceses que tan buen acogida dieron siempre al prehistoriador español. Leyendo la carta de Casiano de Prado objeto de la presente comunicación vemos nos sólo el importante ánimo que tiene su autor en pro de los estudios prehistóricos, sino la efervescencia de los estudios prehistóricos en su país vecino.se escribe en Mayo de 1865 en París adonde había ido a divulgar su Descripción Física y Geológica de la Provincia de Madrid (1864). En la carta se puede seguir perfectamente el círculo de relaciones y amistades que había establecido Prado con el que obtenía el aval científico internacional que necesitaba tanto dentro como fuera de nuestras fronteras para poder defender unos estudios como los prehistóricos que despertaban recelos en buena parte de la sociedad

Elevated stratopause events in the current and a future climate: A chemistry-climate model study

The characteristics and driving mechanisms of Elevated Stratopause Events (ESEs) are examined in simulations of the ECHAM/MESSy Atmospheric Chemistry (EMAC) chemistry-climate model under present and projected climate conditions. ESEs develop after sudden stratospheric warmings (SSWs) in boreal winter. While the stratopause descends during SSWs, it is reformed at higher altitudes after the SSWs, leading to ESEs in years with a particularly high new stratopause. EMAC reproduces well the frequency and main characteristics of observed ESEs. ESEs occur in 24% of the winters, mostly after major SSWs. They develop in stable polar vortices due to a persistent tropospheric wave forcing leading to a prolonged zonal wind reversal in the lower stratosphere. By wave filtering, this enables a faster re-establishment of the mesospheric westerly jet, polar downwelling and a higher stratopause. We find the presence of a westward-propagating wavenumber-1 planetary wave in the mesosphere following the onset, consistent with in-situ generation by large-scale instability. By the end of the 21st century, the number of ESEs is projected to increase, mainly due to a sinking of the original stratopause after strong tropospheric wave forcing and planetary wave dissipation at lower levels. Future ESEs develop preferably in more intense and cold polar vortices, and tend to be shorter. While in the current climate, planetary wavenumber-2 contributes to the forcing of ESEs, future wave forcing is dominated by wavenumber-1 activity as a result of climate change. Hence, a persistent wave forcing seems to be more relevant for the development of an ESE than the wavenumber decomposition of the forcing

Intraseasonal effects of El Niño-Southern Oscillation on North Atlantic climate

This is the final version. Available from American Meteorological Society via the DOI in this record.It is well established that El Niño-Southern Oscillation (ENSO) impacts the North Atlantic-European (NAE) climate, with the strongest influence in winter. In late winter, the ENSO signal travels via both tropospheric and stratospheric pathways to the NAE sector and often projects onto the North Atlantic Oscillation. However, this signal does not strengthen gradually during winter, and some studies have suggested that the ENSO signal is different between early and late winter and that the teleconnections involved in the early winter subperiod are not well understood. In this study, we investigate the ENSO teleconnection to NAE in early winter (November-December) and characterize the possible mechanisms involved in that teleconnection. To do so, observations, reanalysis data and the output of different types of model simulations have been used. We show that the intraseasonal winter shift of the NAE response to ENSO is detected for both El Niño and La Niña and is significant in both observations and initialized predictions, but it is not reproduced by free-running Coupled Model Intercomparison Project phase 5 (CMIP5) models. The teleconnection is established through the troposphere in early winter and is related to ENSO effects over the Gulf of Mexico and Caribbean Sea that appear in rainfall and reach the NAE region. CMIP5 model biases in equatorial Pacific ENSO sea surface temperature patterns and strength appear to explain the lack of signal in the Gulf of Mexico and Caribbean Sea and, hence, their inability to reproduce the intraseasonal shift of the ENSO signal over Europe.European CommissionEuropean CommissionNatural Environment Research Council (NERC

Jet stream position explains regional anomalies in European beech forest productivity and tree growth

The mechanistic pathways connecting ocean-atmosphere variability and terrestrial productivity are well-established theoretically, but remain challenging to quantify empirically. Such quantification will greatly improve the assessment and prediction of changes in terrestrial carbon sequestration in response to dynamically induced climatic extremes. The jet stream latitude (JSL) over the North Atlantic-European domain provides a synthetic and robust physical framework that integrates climate variability not accounted for by atmospheric circulation patterns alone. Surface climate impacts of north-south summer JSL displacements are not uniform across Europe, but rather create a northwestern-southeastern dipole in forest productivity and radial-growth anomalies. Summer JSL variability over the eastern North Atlantic-European domain (5-40E) exerts the strongest impact on European beech, inducing anomalies of up to 30% in modelled gross primary productivity and 50% in radial tree growth. The net effects of JSL movements on terrestrial carbon fluxes depend on forest density, carbon stocks, and productivity imbalances across biogeographic regions. Here the authors show that extremes in the summer jet stream position over Europe create a beech forest productivity dipole between northwestern and southeastern Europe and can result in regional anomalies in forest carbon uptake and growth