1,744 research outputs found
La mascarilla obligatoria en educación primaria no frenó el coronavirus de manera significativa
Document relacionat: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4046809Desde el principio de la pandemia de covid-19, la obligación del uso de mascarillas ha sido una de las
medidas impuestas para intentar reducir la transmisión que más controversia ha generado. El debate
se ha centrado principalmente en su uso en exteriores, si conllevan perjuicios para la salud y si son
efectivas.
Diversos estudios experimentales han mostrado que la eficacia de las mascarillas para impedir la
emisión o inhalación de partículas está entre el 20 y el 90 %. Estos porcentajes varían según el tipo de
mascarilla, el tiempo de uso y el nivel de ajuste. Reducciones similares se han encontrado al analizar
la transmisión entre animales de laboratorio y en entornos humanos muy controlados.Postprint (published version
Aircraft clouds: from chemtrail pseudoscience to the science of contrails
The most frequent statements and arguments found in pseudoscience websites and forums supporting the existence of so-called aircraft chemtrails can be refuted with a scientific explanation of the processes resulting in the formation of condensation or deposition trails, known as contrails. Thus, the hypothesis that chemtrails exist is disproven by the scientific literature that shows that they are the exact same entity as contrails: They are hydrological phenomena which result from a physical process referenced in the many studies carried out since the beginning of the age of aviation, in the early twentieth century. Hence, in this paper we conclude that pseudoscience’s chemtrails are nothing more than the contrails described by science.Peer ReviewedVersió final publicad
Simulació numèrica de fronts costaners nocturns a la conca de la Mediterrània
During the night, inland air cools faster than the air near the coast or above the water bodies (in our case the Mediterranean Sea). Due to this temperature difference, the colder air moves offshore driven by drainage wind following the river valleys, streams and down slope the mountain ranges.
A coastal front is formed when the colder air mass interacts with the warm and moist maritime air mass. This interaction enhances the vertical movement of the warm air mass that cools and may condensate forming clouds and in some cases producing precipitation.
This nocturnal coastal front formation has been analyzed and quantified by using observations and the results of the numerical experiments performed with the WRF-ARW mesoscale model. The role of, for instance, the shape of the coast and the sea surface temperature, is investigated.Peer ReviewedPostprint (published version
Meteodiversity: a new concept for quantifying meteorological diversity
This is the peer reviewed version of the following article: Mazon, J., Pino, D. Meteodiversity: a new concept for quantifying meteorological diversity. "Weather", 10 Maig 2017, vol. 72, núm. 5, p. 143-145., which has been published in final form at http://onlinelibrary.wiley.com/wol1/doi/10.1002/wea.2945/abstract. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.Inspired by the concept of biodiversity used by biologists and ecologists, the concept of meteodiversity is proposed as a method of characterising the variety of meteorological phenomena in a defined area within a specified period. Similarly to the term biodiversity, meteodiversity takes into account the proportion of individual meteorological phenomena belonging to the main weather that occur in a defined area. The benefits and importance of using this concept are discussed.
For quantification purposes, we propose a meteodiversity index, which, in addition to events and phenomena, should include a large number of atmospheric variables obtained from instrumental and observational records. This index itemises not only events ans phenomena, but also a large number of atmospheric variables obtained from instrumental and observational records.
We use climatic data obtained from the Met Office and European Climate Assessment and Dataset project to evaluate the meteodiversity index, first on a monthly scale for the period 1981–2014 at Llanfairpwllgwyngyll (UK), and then on an annual scale for 1962–2014 at Barcelona (Spain) and Helsinki (Finland). The weather diversity and the trends over these cities have been analyzed.Peer ReviewedPostprint (author's final draft
Trend of flash heat events in the Iberian Peninsula during the period 1900-2010
Peer ReviewedPostprint (published version
The influence of an increase of the Mediterranean Sea Surface Temperature on two nocturnal offshore rainbands: a numerical experiment
Using the Weather Research and Forecasting (WRF) – Advanced Research WRF (ARW)
mesoscale model (WRF–ARW), we investigate how two nocturnal offshore rainbands occurring in
the Mediterranean basin are modified in a warmer sea surface temperature (SST). After sunset, the
thermal difference between land and sea air increases. Driven by drainage winds or land breeze, the
inland cold air interacts with the relatively warmer and moister air over the sea. Vertical movement
of sea air over the boundary between the two air masses may induce cloud and rain bands offshore.
When an increase of SST is prescribed in the WRF simulations, a change in the precipitation pattern is
simulated. The numerical experiments show an increase both in the extension and location of the
rainbands and in the precipitation rate. These changes, induced by the modified SST, are analyzed by
estimating and comparing several parameters such as the location of level of free convection (LFC),
Convective Available Potential Energy (CAPE), or the triggering, deceleration and blockage terms of
simplified conceptual models.Peer ReviewedPostprint (published version
Cold outbreaks at the mesoscale in the Western Mediterranean basin: from Raincells to rainbands
This paper investigates cold outbreaks that form offshore density currents within the whole mesoscale over the Western
Mediterranean basin. Reflectivity radar and satellite images are used to detect clouds and precipitation that are associated with these
density currents in the meso-
훼
,meso-
훽
, and meso-
훾
over the Western Mediterranean basin (WMB). Version 3.3 of the WRF-ARW
model is used to describe the formation and evolution of these density currents and to estimate their lifetime as well as horizontal
and vertical scales. Based on the observations and simulations, this paper suggests that a new perspective could effectively be
adopted regarding the WMB region delineated by the Balearic Islands, the northeastern Iberian Peninsula, and the Gulf of Lion,
where inland cold outbreaks develop into density currents that move offshore and can produce precipitation ranging from raincells
to rainbands at the whole mesoscale.Peer ReviewedPostprint (published version
The role of large sea-land temperature, the coastline shape and the SST in
Peer ReviewedPostprint (published version
Frontogenesis in the meso-a and meso-ß scales in the Mediterranean basin: From cloud arch to cloud cells.
Postprint (published version
Nocturnal offshore precipitation near the coastline in the Mediterranean basin
Peer ReviewedPostprint (published version
- …