A Lagrangian analysis of the variation in moisture sources related to drier and wetter conditions in regions around the Mediterranean Basin

Here, we describe our use of the Lagrangian 3-D FLEXPART model to investigate the variation in sources of moisture related to the drier and wetter conditions of the different regions that surround the Mediterranean Basin. We carried out seasonal analyses for the period from March 2000 to February 2005, and identified those years with the highest and lowest rates of precipitation by season, averaged over eight different continental regions. The variation in specific humidity along the 10-day backward trajectories of the particles identified over the target areas was tracked for the selected period, and the characteristics of the moisture sources were then compared between wetter and drier conditions by season. Although they only represented a relatively short period, the results suggest that in most of the years chosen, the moisture sources were more extensive and/or more intense during wetter periods. The contribution of the north Atlantic as a source of moisture is apparent for the Iberian Peninsula, for France and for Central North Africa. Otherwise, the Mediterranean Sea is the predominant source for Eastern North Africa, and for the Italian and Balkan Peninsulas. Local sources provide moisture for the Eastern Mediterranean and Western North Africa

Impact of missing sounding reports on mandatory levels and tropopause statistics: a case study

This paper describes the effect of missing sounding reports on temperature and pressure mean values for mandatory levels using the aerological information from the Camagüey Meteorological Centre. Also it is described the effect of missing data on mean temperature and pressure values at the multiple tropopause levels. The case study belongs to one station for a time lag of eight years. Up to the present these types of studies have been conducted using simulated datasets. The present one uses a real inhomogeneous radiosonde dataset. The main reason for missing reports were transmission problems and possible encoding-decoding difficulties. It has been found that profiles of the mean temperature and altitude show little differences between the complete and incomplete datasets. Moreover, no statistical significant differences were found for the mean values of the variables for the complete and incomplete datasets. The most probable reason for those results is that the cause of the missing reports has a random behaviour. Finally we have found that the only two effects noticed on the statistics were slightly higher values of the mean temperatures in the complete dataset and the decrease in the percent of multiple tropopause reports for the incomplete dataset

CLIWOC multilingual meteorological dictionary

This dictionary is the first attempt to express the wealth of archaic logbook wind force terms in a form that is comprehensible to the modern-day reader. Oliver and Kington (1970) and Lamb (1982) have drawn attention to the importance of logbooks in climatic studies, and Lamb (1991) offered a conversion scale for early eighteenth century English wind force terms, but no studies have thus far pursued the matter to any greater depth. This text attempts to make good this deficiency, and is derived from the research undertaken by the CLIWOC project1 in which British, Dutch, French and Spanish naval and merchant logbooks from the period 1750 to 1850 were used to derive a global database of climatic information. At an early stage in the project it was apparent that many of the logbook weather terms, whilst conforming to a conventional vocabulary, possessed meanings that were unclear to twenty-first century readers or had changed over time. This was particularly the case for the important element of wind force; but no special plea is entered for the evolution in nautical vocabulary, which often reflected more wide-ranging changes in the respective native languages.The key objective was to translate the archaic vocabulary of the late eighteenth and early nineteenth century mariner into expressions directly comparable with the Beaufort Scale (see Appendix I). Only then could the projects scientific programme be embarked upon. This dictionary is the result of the largest undertaking into logbook studies that has yet been carried out. Several thousand logbooks from British, Dutch, French and Spanish archives were examined, and the exercise offered a unique opportunity to explore the vocabulary of the one hundred year period beginning in 1750. The logbooks from which the raw data have been abstracted range widely across the North and South Atlantic and the Indian Oceans. Only the Pacific, largely in consequence of the paucity of regular naval activity in that area, is not well represented. The range of climates encountered in this otherwise wide geographic domain gives ample opportunity for the full range of the mariners nautical weather vocabulary to be assessed, from the calms of the Equatorial regions, through the gales of the mid-latitude systems to the fearsome storms of the tropical latitudes. The Trade Winds belts, the Doldrums, the unsettled mid-latitudes, even the icy wastes of the high latitudes, are all embraced in this study. It is not here intended to pass any judgements on the climatological record of the logbooks, and this text seeks only to provide a means of understanding archaic wind force terms and, other than to indicate those items that were not commonly used, no information is given on the frequency with which different terms appeared in the logbooks. Attention is, furthermore, confined to Dutch, English, French and Spanish because these once great imperial powers were the only nations able to support wide-ranging ocean-going fleets with their attendant collections of logbooks and documents over this long period of time. The work is offered to the wider academic community in the hope that they will prove to be of as much value as it has been to the CLIWOC team

Drought effects on specific-cause mortality in Lisbon from 1983 to 2016: risks assessment by gender and age groups

Portugal (Southwestern Europe) experiences a high incidence of dry hazards such as drought, a phenomenon that entails a notable burden of morbidity and mortality worldwide. For the first time in the Lisbon district, a time-series study was conducted to evaluate the impact of drought measured by the Standardised Precipitation Index (SPI) and Standardised Precipitation-Evapotranspiration Index (SPEI) on the daily natural, circulatory, and respiratory mortality from 1983 to 2016. An assessment by gender and adult age population groups (45-64, 65-74, ≥75 years old) was included. To estimate the relative risks and attributable risks, generalised linear models with a Poisson link were used. Additionally, the influence of heatwaves and atmospheric pollution for the period from 2007 to 2016 (available period for pollution data) was considered. The main findings indicate statistically significant associations between drought conditions and all analysed causes of mortality. Moreover, SPEI shows an improved capability to reflect the different risks. People in the 45-64 year-old group did not indicate any significant influence in any of the cases, whereas the oldest groups had the highest risk. The drought effects on mortality among the population varied across the different study periods, and in general, the men population was affected more than the women population (except for the SPEI and circulatory mortality during the long study period). The short-term influence of droughts on mortality could be explained primarily by the effect of heatwaves and pollution; however, when both gender and age were considered in the Poisson models, the effect of drought also remained statistically significant when all climatic phenomena were included for specific groups of the total population and men. This type of study facilitates a better understanding of the population at risk and allows the development of more effective measures to mitigate the drought effects on the population.publishe

An explanation for the isotopic offset between soil and stem water in a temperate tree species

A growing number of field studies report isotopic offsets between stem water and its potential sources that prevent the unambiguous identification of plant water origin using water isotopes. We explored the causes of this isotopic offset by conducting a controlled experiment on the temperate tree species Fagus sylvatica. We measured d2H and d18O of soil and stem water from potted saplings growing on three soil substrates and subjected to two watering regimes. Regardless of substrate, soil and stem water d2H were similar only near permanent wilting point. Under moister conditions, stem water d2H was 11 ± 3 more negative than soil water d2H, coherent with field studies. Under drier conditions, stem water d2H became progressively more enriched than soil water d2H. Although stem water d18O broadly reflected that of soil water, soil stem d2H and d18O differences were correlated (r = 0.76) and increased with transpiration rates indicated by proxies. Soil stem isotopic offsets are more likely to be caused by water isotope heterogeneities within the soil pore and stem tissues, which would be masked under drier conditions as a result of evaporative enrichment, than by fractionation under root water uptake. Our results challenge our current understanding of isotopic signals in the soil plant continuum. © 2020 The Authors. New Phytologist © 2020 New Phytologist TrustThis work was supported by the French national programme EC2CO-Biohefect (RootWater), the French national research agency (projects Hydrobeech, Climbeech and Micromic within the Cluster of Excellence COTE with grant agreement ANR-10-LABX-45; project ORCA with grant agreement ANR-13-BS06-0005-01), the European Research Council (ERC) under the EU Seventh Framework Program (FP7/2007-2013, with grant agreement no. 338264, awarded to LW) and the Aquitaine Region (project Athene with grant agreement 2016-1R20301-00007218). AB also acknowledges an IdEx Bordeaux postdoctoral fellowship from the Universite de Bordeaux (contract no. 22001162)

Classification of Marek's disease viruses according to pathotype: Philosophy and methodology

El concepto de patotipo en la enfermedad de Marek (MD) data probablemente de finales de los 1950s cuando se reconoció una forma más virulenta de enfermedad Benton y Cover, 1957). Las distinciones entre las diferentes cepas de virus de MD (MDV) fueron aún mayores al describirse el patotipo vv a principios de los ochenta y el vv+ en los noventa. La designación de patotipo refleja propiedades biológicas importantes que se correlacionan con la capacidad de romper la inmunidad maternal en el campo. A pesar de ello, los métodos de clasificación de los diferentes patotipos en varios laboratorios no han sido uniformes, lo cual ha impedido una comparación crítica de los resultados. El método utilizado en el Avian Disease and Oncology Laboratory (ADOL) se basa en la inducción de lesiones linfoproliferativas en pollos vacunados. Este método ha sido utilizado para clasificar más de 45 aislados y es la base para la clasificación actual de los patotipos de cepas de MDV. Las limitaciones de este método son varias: necesidad de un tipo específico de pollos (15x7 ab+), uso de un gran número de animales y de un método estadístico para comparar las respuestas lesionales con las de las cepas control JM/102W y Md5. Debido a estas limitaciones no ha sido y no es probablemente usado en otros laboratorios. La comparación en el patotipado puede ser mejorada mediante la comparación de aislados de campo con cepas prototipo como las JM/102W, Md5 y 648A (American Type Culture Collection) o sus equivalentes. Los datos pueden ser generados mediante diferentes procedimientos in vivo que miden la inducción de tumores, enfermedad neurològica (por lesiones neoplásicas o no neoplásicas), o únicamente por criterios no neoplásicos (como el peso de los órganos linfoides o la replicación vírica). Los métodos basados en criterios neoplásicos, especialmente cuando son generados en pollos inmunizados de MD, probablemente se correlacionarán mejor con el método del ADOL y serán más relevantes en cuanto a la evolución de los virus de MD en el campo. En base a los datos de diferentes experimentos, se propone una modificación del método ADOL que utiliza menos animales y puede ser llevado a cabo en pollos SPF comerciales. El método modificado se basa en una comparación con el que mejor clasifica las cepas prototipo, y se espera que de resultados en general comparables con el método original. Otros criterios alternativos (ver abajo) también se evalúan como métodos primarios de patotipificación o como adjuntos a otros métodos de patotipificación. Se presentan las ventajas y desventajas de estos métodos alternativos.The concept of pathotype in Marek's disease (MD) probably dates from the recognition of a more virulent form of the disease in the late 1950s (Benton & Cover, 1957). Distinctions between MD virus strains were further expanded with the description of the vv pathotype in the early 1980s and of the vv + pathotype in the 1990s. Pathotype designations reflect important biological properties that correlate with the break-through of vaccinal immunity in the field. However, pathotyping methods applied by various laboratories have not been uniform, preventing critical comparison of results. Better uniformity of pathotyping procedures is desirable. The Avian Disease and Oncology Laboratory (ADOL) method is based on induction of lymphoproliferative lesions in vaccinated chickens. This method has been used to pathotype more than 45 isolates and is the basis for the current pathotype classification of MD virus strains. Its limitations include requirements for a specific type of chickens (15 x 7 ab+), large numbers of animals, and a statistical method to compare lesion responses to those of JM/102W and Md5 control strains. Because of these limitations, it has not been and is not likely to be used in other laboratories. Comparability in pathotyping can be improved by the comparison of field isolates with standard prototype strains such as JM/102W, Md5 and 648A (American Type Culture Collection) or their equivalents. Data may be generated by different in vivo procedures that measure tumour induction, neurological disease (both neoplastic and non-neoplastic lesions), or solely non-neoplastic criteria (such as lymphoid organ weights or virus replication). Methods based on neoplastic criteria, especially when generated in MD-immunized chickens, will probably correlate most closely with that of the ADOL method and be most relevant to evolution of MD virus in the field. Based on data from several trials, a modification of the ADOL method that utilizes fewer chickens and can be conducted with commercial specific pathogen free strains is proposed. The modified method is based on "best fit" comparisons with prototype strains, and is expected to provide results generally comparable with the original method. A variety of other alternative criteria (see earlier) are also evaluated both for primary pathotyping and as adjuncts to other pathotyping methods. Advantages and disadvantages of alternative methods are presented.Facultad de Ciencias Veterinaria

Corrigendum to "Increase of upper troposphere/lower stratosphere wave baroclinicity during the second half of the 20th century" published in Atmos. Chem. Phys., 9, 9143–9153, 2009

No abstract available