893 research outputs found
Arctic marine climate of the early nineteenth century
The climate of the early nineteenth century is likely to have been significantly cooler than that of today, as it was a period of low solar activity (the Dalton minimum) and followed a series of large volcanic eruptions. Proxy reconstructions of the temperature of the period do not agree well on the size of the temperature change, so other observational records from the period are particularly valuable. Weather observations have been extracted from the reports of the noted whaling captain William Scoresby Jr., and from the records of a series of Royal Navy expeditions to the Arctic, preserved in the UK National Archives. They demonstrate that marine climate in 1810 - 1825 was marked by consistently cold summers, with abundant sea-ice. But although the period was significantly colder than the modern average, there was considerable variability: in the Greenland Sea the summers following the Tambora eruption (1816 and 1817) were noticeably warmer, and had less sea-ice coverage, than the years immediately preceding them; and the sea-ice coverage in Lancaster Sound in 1819 and 1820 was low even by modern standards. © 2010 Author(s)
Dip-coated La2Ti2O7 as a buffer layer for growth of Bi3.25La0.75Ti3O12 films with enhanced (0 1 1) orientation
Thin-films of La2Ti2O7 were obtained by dip-coating process using a precursor salt in nitric acid solution. The effects of solution concentration, withdrawal speed, post-annealing duration and temperature were investigated both on grain size and orientation of the La2Ti2O7 thin layers. In addition, a target with the required stoichiometry for PVD deposition of La-substituted Bi4Ti3O12 (BLT) was successfully sintered by spark plasma sintering (SPS) at 750 ◦C. Finally (0 1 1)-oriented BLT ferroelectric films have been grown by RF sputtering on (1 1 0)-oriented La2Ti2O7 polycrystalline thin-film. A preferential orientation of BLT thin films has been obtained after annealing at a temperature lower than 650 ◦C
Global analysis of night marine air temperature and its uncertainty since 1880: the HadNMAT2 Dataset
An updated version of the Met Office Hadley Centre’s monthly night marine air temperature dataset is presented. It is available on a 5? latitude-longitude grid from 1880 as anomalies relative to 1961-1990 calendar-monthly climatological average night marine air temperature (NMAT). Adjustments are made for changes in observation height; these depend on estimates of the stability of the near surface atmospheric boundary layer. In previous versions of the dataset, ad hoc adjustments were also made for three periods and regions where poor observational practice was prevalent. These adjustments are re-examined. Estimates of uncertainty are calculated for every grid box and result from: measurement errors; uncertainty in adjustments applied to the observations; uncertainty in the measurement height and under-sampling. The new dataset is a clear improvement over previous versions in terms of coverage because of the recent digitization of historical observations from ships' logbooks. However, the periods prior to about 1890 and around World War 2 remain particularly uncertain and sampling is still sparse in some regions in other periods. A further improvement is the availability of uncertainty estimates for every grid box and every month. Previous versions required adjustments that were dependent on contemporary measurements of sea surface temperature (SST); to avoid these, the new dataset starts in 1880 rather than 1856. Overall agreement with variations of SST is better for the updated dataset than for previous versions, maintaining existing estimates of global warming and increasing confidence in the global record of temperature variability and change
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Time of emergence of climate signals
The time at which the signal of climate change emerges from the noise of natural climate variability (Time of Emergence, ToE) is a key variable for climate predictions and risk assessments. Here we present a methodology for estimating ToE for individual climate models, and use it to make maps of ToE for surface air temperature (SAT) based on the CMIP3 global climate models. Consistent with previous studies we show that the median ToE occurs several decades sooner in low latitudes, particularly in boreal summer, than in mid-latitudes. We also show that the median ToE in the Arctic occurs sooner in boreal winter than in boreal summer. A key new aspect of our study is that we quantify the uncertainty in ToE that arises not only from inter-model differences in the magnitude of the climate change signal, but also from large differences in the simulation of natural climate variability. The uncertainty in ToE is at least 30 years in the regions examined, and as much as 60 years in some regions. Alternative emissions scenarios lead to changes in both the median ToE (by a decade or more) and its uncertainty. The SRES B1 scenario is associated with a very large uncertainty in ToE in some regions. Our findings have important implications for climate modelling and climate policy which we discuss
Fidel Gabriel Castillo. La Amazonía boliviana indígena. Estudio etnohistórico de la economía, la sociedad y la civilización de los pueblos de las selvas bolivianas
Todo aquel que tenga interés por los grupos amazónicos del piedemonte andino boliviano y por su historia, conoce muy bien a Fidel Castillo. Es autor de varias publicaciones sobre los Chimane y sobre los diversos componentes del conjunto etnolingüístico takana así como de una tesis de doctorado en etnología, sustentada en París en 1985, sobre la historia de estas mismas sociedades en los siglos XVI y XVII (Castillo, 1988; 1995; 1985). La presente obra constituye su traducción al castellano. Su..
Combès Isabelle, Etno-historias del Isoso. Chané y chiriguanos en el Chaco boliviano (siglos xvi a xx), Fundación PIEB / Institut français d’études andines, La Paz, 2005, 396 p., bibl., index, ill., tabl., cartes
Avec Etno-historias del Isoso d’Isabelle Combès, les spécialistes des basses terres et des sociétés de l’Orient bolivien en général disposent désormais d’une nouvelle référence d’ethnohistoire incontournable. À notre avis, cet ouvrage ne constitue pas seulement « l’œuvre définitive pour longtemps [sur les Isoseño] », comme l’annonce Erick Langer dans son prologue, ni même une précieuse contribution chaqueña à l’étude de thèmes d’actualité sur l’américanisme tropical tels que la nature du pouv..
José Luis Roca. Economía y Sociedad en el Oriente Boliviano (siglos XVI-XX)
Son muy pocas las obras de historia sobre el Oriente boliviano por lo que la publicación de esta suma de más de 650 páginas que propone, a partir del análisis de fuentes de época y de estudios más recientes, un examen global de la región que cubre los cuatro últimos siglos y medio (desde la fundación de la ciudad de Santa Cruz de la Sierra hasta nuestros días) no debería pasar desapercibida. Con mayor razón porque el autor, especialista del regionalismo en Bolivia (Cf. Roca, 1999 [1980]; 2001..
Luisa Elvira Belaunde. Viviendo Bien. Género y Fertilidad entre los Airo-Pai de la Amazonía peruana
Cet ouvrage attachant constitue la version espagnole, revue et corrigée, de la thèse doctorale (Belaunde, 1992) que l’auteur consacra au début des années 1990 aux Airo- Pai d’Amazonie péruvienne. Plus généralement désigné par l’exonyme Secoya, ce groupe de faible démographie et appartenant à la famille linguistique tukano occidentale occupe, à la limite de la Colombie, la zone comprise entre les fleuves Napo et Putumayo, de part et d’autre de la frontière péruano-équatorienne. Outre cette sit..
Myers Rodica, Cuando el sol caminaba por la tierra. Orígenes de la intermediación kallawaya, Ediciones Plural, La Paz, 2002, 156 p., bibl., ill., carte, tabl.
Les Kallawaya de Bolivie sont aujourd’hui bien connus d’un point de vue ethnographique, même si l’attention des chercheurs s’est très largement polarisée sur leur système rituel et sur l’activité thérapeutique à l’origine de leur renommée dans tout le continent sud-américain. Cependant, ils continuent à être une « énigme ethnohistorique », pour reprendre l’expression du regretté Thierry Saignes, précurseur en matière d’historiographie kallawaya. C’est cette énigme que ce court ouvrage s’emplo..
L’Odyssée pascuane. Mission Métraux-Lavachery, île de Pâques (1934-1935),
Christine Laurière, L’Odyssée pascuane. Mission Métraux-Lavachery, île de Pâques (1934-1935), Paris, Lahic-Ministère de la Culture et de la Communication, 2014, 198 p., bibl., ill., (« Les Carnets de Bérose » 3) [http://www.berose.fr/IMG/pdf/cl_27_10_web.pdf] Six ans après la publication remarquée de sa biographie intellectuelle et institutionnelle de Paul Rivet, Christine Laurière nous livre une étude brève mais dense sur l’histoire insolite de la mission Métraux-Lavachery à l’île de Pâques ..
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