Evaluación integral de la precipitación en la Sierra de Guadarrama mediante observación y modelización

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Física de la Tierra, Astronomía y Astrofísica I (Geofísica y Meteorología) (Astronomía y Geodesia), leída el 23-10-2015Depto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEunpu

Characterising large-scale meteorological patterns associated with winter precipitation and snow accumulation in a mountain range in the Iberian Peninsula (Sierra de Guadarrama)

Snow precipitation in mountains surrounded by semi-arid regions represents an important reservoir of fresh water during the melting season. The snow cover helps to compensate for the scarce precipitation that occurs during their long summer droughts. Knowing the phenomenology that leads to winter precipitation and snow at these areas becomes even more relevant in a context of climate change. Precipitation in Sierra de Guadarrama, a medium size mountain range in the middle of the Iberian Plateau, is the main source of fresh water for millions of inhabitants living under its area of influence, for an active industry and for agriculture and farming. In addition, scarce but heavy snow events affect logistics, transport and security in an area with abundant ground and air traffic. This work analyses the links between large scale atmospheric patterns and the complex winter precipitation and snow cover dynamics observed at local scale. Applying principal component analysis and K-means clustering on geopotential height field, a set of circulation weather types are obtained. The contribution of each circulation weather type to precipitation, snow and heavy snow events is analysed, and favouring conditions leading to snowfalls are identified. Results from this work can be useful as a framework for future modelling exercises, statistical downscaling of climate change scenarios, or even for the development of early warning systems

SmartFIS: utilizando los teléfonos móviles en el aprendizaje de la Física

El Objetivo General del Proyecto de Innovación “SmartFis” se centraba en facilitar el aprendizaje de los contenidos propios de las múltiples asignaturas impartidas en el Laboratorio de Física General de la Facultad de Ciencias Físicas, en varias titulaciones, mediante la utilización de nuevos recursos didácticos, desarrollando nuevas prácticas de laboratorio basadas en el uso de smartphones, nuevos métodos docentes de laboratorio, y nuevos recursos en el Campus Virtual UCM

Multi-scale evaluation of a linear model of orographic precipitation over Sierra de Guadarrama (Iberian Central System)

El texto completo de este trabajo no se encuentra disponible por no haber sido facilitado aún por su autor, por restricciones de copyright, o por no existir una versión digitalA linear model of orographic precipitation is validated at Sierra de Guadarrama (Iberian Central System) using ERA-Interim as input and a historical set of precipitation data. It is the first time that a linear precipitation model is tested in a semi-arid region like this. The historical precipitation data come from three high-quality observatories located at the south, north and top of the mountain range. Different timescales ranging from daily, monthly and annual precipitation are analysed. Phenomena not generally taken into account in linear models like a sub-saturated air condition and topographic mesoscale flow blocking are included in the modelling. Model results show a good agreement with observations at annual and monthly scales. The model reproduces well the high inter-annual variability and the annual cycle, including the pronounced summer drought. Bigger differences between observed and modelled precipitations are found for some winter months and for May. Winter overestimation is attributed to measurement undersampling during snowy conditions. The underestimation in May is likely related to thermally driven convective precipitation, which is not modelled. Results also show how orographic precipitation is an important contributor to total precipitation in this area. The high-resolution precipitation fields obtained can be used in the future for precipitation assessment and other hydrological applications. Modelled time series can also be very helpful for completing and validating the precipitation observations for the winter months.NILS Science and Sustainability ProgramResearch Council of Norway (SNOWPACE project)Depto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEpu

The Peñalara Mountain Meteorological Network (1999–2014): description, preliminary results and lessons learned

This work describes a mountain meteorological network that was in operation from 1999 to 2014 in a mountain range with elevations ranging from 1104 to 2428 m in Central Spain. Additionally, some technical details of the network are described, as well as variables measured and some meta information presented, which is expected to be useful for future users of the observational database. A strong emphasis is made on showing the observational methods and protocols evolution, as it will help researchers to understand the sources of errors, data gaps and the final stage of the network. This paper summarizes mostly the common sources of errors when designing and operating a small network of this kind, so it can be useful for individual researchers and small size groups that undertake a similar task on their own. Strengths and weaknesses of some of the variables measured are discussed and some basic calculations are made in order to show the potential of the database and to anticipate future deeper climatological analyses over the area. Finally, the configuration of an automatic mountain meteorology station is suggested as a result of the lessons learned and the the common state of the art automatic measuring techniques.Parque Natural de PeñalaraDepto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEpu

New approaches and error assessment to snow cover thickness and density using air temperature data at different heights

Snow poles are inexpensive systems composed of a wooden mast with temperature sensors affixed at varying heights with the purpose of estimating the snow depth. They are frequently utilised in cold, remote regions where the maintenance of complex monitoring instruments becomes impractical. In this study, snow cover thickness is determined using different methods, based on the thermal behaviour of air temperature measured by a snow pole on Deception Island, Antarctica. The methods are compared to high-resolution measurements of snow depth obtained using an ultrasonic sensor at the same site. A new modified method is proposed and shown to give the best results. Errors and sensitivity to chosen thresholds of the various methods have been compared. Sensitivity tests have been also conducted to evaluate the impact of missing data from some of the sensors. Finally, the insulating effect on the thermal signal produced by the snow is used to obtain information on the snowpack density. Promising results have been found from this effort, opening new possibilities for the usage of snow poles and may lead to future studies.Government of Spain, Ministry of Economy and CompetitivitySpanish Polar Committee by contracts PERMATHERMALProyectos de Generación de Conocimiento 2022, Ministry of Science and Innovation, SpainDepto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEpu

Climate change and outbreaks of amphibian chytridiomycosis in a montane area of Central Spain; is there a link?

El texto completo de este trabajo no se encuentra disponible por no haber sido facilitado aún por su autor, por restricciones de copyright, o por no existir una versión digitalAmphibian species are declining at an alarming rate on a global scale in large part owing to an infectious disease caused by the chytridiomycete fungus, Batrachochytrium dendrobatidis. This disease of amphibians has recently emerged within Europe, but knowledge of its effects on amphibian assemblages remains poor. Importantly, little is known about the environmental envelope that is associated with chytridiomycosis in Europe and the potential for climate change to drive future disease dynamics. Here, we use long-term observations on amphibian population dynamics in the Penalara Natural Park, Spain, to investigate the link between climate change and chytridiomycosis. Our analysis shows a significant association between change in local climatic variables and the occurrence of chytridiomycosis within this region. Specifically, we show that rising temperature is linked to the occurrence of chytrid-related disease, consistent with the chytrid-thermal-optimum hypothesis. We show that these local variables are driven by general circulation patterns, principally the North Atlantic Oscillation. Given that B. dendrobatidis is known to be broadly distributed across Europe, there is now an urgent need to assess the generality of our finding and determine whether climate-driven epidemics may be expected to impact on amphibian species across the wider region.Fundación BBVANatural Environment Research Council (NERC)Depto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEpu

Seasonal behavior of aerosol vertical concentration in dakar and role played by the sea-breeze

The Westward transport of mineral dust from the North Africa continent to Atlantic Ocean can produce poor air quality, low visibilities, and negatively impacting respiratory and cardiac health due to the optical and physical properties of aerosols. The dynamical impact of the sea-breeze on the dust vertical distribution in West Africa remains unknown. To investigate this issue, we have used in-situ measurements from lidar. We have focused on the attenuated backscatter of aerosols to study the effect of the local circulation on the vertical profile of mineral dust at land-sea transition. The results highlight a strong diurnal cycle of mineral dust associated with the nocturnal low-level jet (NLLJ). The jet is located between 500 m and 1000 m and crucially affected by the dynamic of the sea-breeze circulation.Depto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEpu

Water vapour flux patterns and precipitation at Sierra de Guadarrama mountain range (Spain)

It is well known how mountains play a crucial role in the climate system and have very particular climate features compared to other regions. Sierra de Guadarrama is a part of the Iberian Peninsula Central System (Spain), a mountain range located in the center of an extensive plateau, dominated by a continental Mediterranean climate but under a strong Atlantic influence. This range provides fresh water to the different settlements in its vicinity, providing enough water resources to several millions of inhabitants, crop fields, industries and the city of Madrid, the capital of Spain. Nevertheless, there is no work studying the role of the synoptic scale in relation to the precipitation in this mountain range. To tackle this problem, this work calculates water vapour flux patterns (WVFPs) using total column water vapour flux as a predictor field due to the close relation between this parameter and the precipitation in mountainous areas. A clustering analysis on the first three principal components of the predictor field was performed and seven differentiated WVFPs were found using a cost function considering local precipitation data for optimum number of cluster determination. Then, an analysis is made for each component in terms of synoptic relation with other fields and well-known broader teleconnection patterns. Finally, an analysis in terms of their contribution to total precipitation, mean rain intensity and probability of precipitation is made. This work is expected to bring new light on the knowledge of precipitation climatology over this crucial and still not very well-known area, and it is a solid step for future precipitation modelling tools validation that combined with reliable measurements will allow to produce realistic precipitation assessments and forecasts in order to improve the hydrological management of this complex area.Depto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEpu