1,050 research outputs found
Estimativa da Evaporação em Albufeiras do Sul de Portugal pelo Modelo FLAKE
The aim of this work is to be able to simulate the evaporation from reservoirs in southern Portugal(a drought prone area) by applying the FLAKE lake model. The model was forced with over-lake atmospheric measurements from the Water Institute monitoring network over the period from 2002 to 2006. Simulation results were compared against observational water temperature profiles and a statistic analysis was used to set optimal model parameters for each reservoir studied. Comparison shows that the model is able to simulate the annual cycle of water temperatures, and to predict realistic patterns of evaporation rates
Coupling of the FLake model to the Surfex externalized surface model
Acoplamento Flake - SURFE
Comparison of cloud height and depth from atmospheric modelling and ceilometer measurements
In the current study, the cloud base height obtained from the ceilometer measurements, in Evora (south of Portugal), are compared with the results obtained from atmospheric modelling. The atmospheric model adopted is the nonhydrostatic MesoNH model, initiated and forced by ECMWF (European Centre for Medium-Range weather Forecasts) analyses. Also the simulated cloud depth results are presented. The availability of mesoscale modelling for the region, as well as the cloud local vertical distributions obtained from the ceilometer, provide a good opportunity to compare cloud base height and estimate the errors associated. From the obtained results it is possible to observe that the simulated cloud base height values are in good agreement with the correspondent values obtained from the ceilometer measurements
ONLINE WORKSHOP ON EARTH AND SPACE SCIENCES - ATMOSPHERIC PHYSICS AND CLIMATE Proceedings Book 2020
This book was produced in the scope of the Curricular Unit Seminar I (Physics
of Atmosphere and Climate) of the PhD program in Earth and Space Sciences,
which included the organization of the 2020 edition of the Online Workshop
on Earth and Space Sciences - Atmospheric Physics and Climate of the
University of Évora. This volume brings together the research articles
produced by students who attended the course. Since its first edition in 2013,
the Workshop has been a space for sharing knowledge and training in science
communication. In this sense, it seeks to provide students who attend Seminar
Units with an effective experience not only in the preparation and presentation
of oral communications and research articles, but also in the organization of
the event itself. In the 2020 edition, which took place on June 4, 11 abstracts
were submitted and presented, covering the various themes of the PhD
program, in addition to two invited lectures
Radiação solar: estudo e criação de plataforma de apoio à conceção de um sensor de radiação solar
Este trabalho apresenta os resultados de uma plataforma de simulação da radiação solar. A plataforma de simulação apresentada permite simular radiação solar através de dados medidos ou dados históricos. Para utilização dos dados históricos, apresenta-se o instrumento Environment Simulator que juntamente com a base de dados meteorológicos permite obter variáveis meteorológicas para qualquer posição e tempo. Os resultados da utilização da plataforma de simulação de radiação solar foram comparados com os valores medidos durante na campanha ALEX2014
Wiinteraction: a study on smart spaces interaction using the Wiimote
This paper describes a study on the use of the Wiimote as a generic interaction
device for smart spaces. We have identified the range of interaction possibilities that can be
explored when creating Wii-based interfaces for smart spaces and we have explored the
application of those interactive features in the context of a typical museum guide. While there
are many features that can be explored creatively to sustain the use of the Wiimote as a generic
interaction device, we also found that there is at least one critical requirement that is not
supported. More specifically, we have identified the need to include access to rich information,
such as the one provided by digital displays. We thus propose a shared control mechanism for
public displays that enables a user equipped with a Wiimote to first gain control and then
browse information in a public display. The results of our study show no major limitation in the
proposed approach, but identify device discovery as one major technical flaw that still needs to
be overcome before the wiimotemay realistically become a generic interaction alternative for
smart spaces
Spatial and temporal downscaling of solar global radiation and mean air temperature from weather forecast data - an introductory numerical study and validation
This short paper presents a numerical method for spatial and temporal downscaling of solar global radiation and mean air temperature data from global weather forecast models and its validation. The final objective is to develop a prediction algorithm to be integrated in energy management models and forecast of energy harvesting in solar thermal systems of medium/low temperature. Initially, hourly prediction and measurement data of solar global radiation and mean air temperature were obtained, being then numerically downscaled to half-hourly prediction values for the location where measurements were taken. The differences between predictions and measurements were analyzed for more than one year of data of mean air temperature and solar global radiation on clear sky days, resulting in relative daily deviations of around -0.9±3.8% and 0.02±3.92%, respectively
Flash Flood in Madeira Island in autumn 2012
Madeira (32º75'N and 17º 00'W) is a Portuguese mountainous island with the highest peaks above 1800 m, where after the catastrophe of 20 February 2010, which has shown to be vulnerable to the flood occurrences from significant socio-economical losses. Using ground observations and the MESO-NH model, this study investigates the main atmospheric aspects related to the flash flood and landslides occurrences on 05 November 2012 in the island. The period between 25 October and 06 November 2012 have been considered in the analysis. The numerical simulations are performed using different configurations, with a single domain of 25 km horizontal resolution and using grid nesting technique with 9, 3 and 1 km resolution. During this period, two main events were chosen based on rain gauge data analysis, to be simulated at high resolution (1km): 30 October and 05 November, when the highest amounts of precipitation in Madeira's highlands and landslides were observed, respectively. Previous studies show that the heavy rainfall events in Madeira depend on both synoptic and mesoscale features, justifying the simulations in different resolutions. The accumulated precipitation simulation pointed out the prominent role of orography in the intensification of precipitation over the island. The possibility of severe weather development was confirmed from some instability indices obtained from radiosonde observations, despite the CAPE index, which indicated a weak instability environment. On the other hand, large-scale environment was characterized by the development of extratropical cyclones near the island, where the frontal structure acting over Madeira's archipelago is evident. A remarkable feature is the fact that on 30 October, coupled to a frontal system, the main moisture source in low-levels was related to an atmospheric river structure passing over the island
NUMERICAL SIMULATIONS OF INTENSE PRECIPITATION IN MADEIRA ISLAND USING THE MESO-NH MODEL
Extreme orographic precipitation events are a common
cause of natural hazards such as flash floods, landslides, and
avalanches in mountainous regions (Roe, 2005), and may be
caused by different mechanisms. Situated in the Subtropical
Atlantic Ocean (32º 45' N and 17º 00'W), Figure 1, the
Madeira Island is the largest island of the Madeira
Archipelago, with surface area of 737 km2, a length of 58
km, a 23 km width and a maximum altitude of 1861m (Pico
Ruivo), consisting of a barrier elongated in the east-west
direction (Prada et al., 2009) and presenting favorable
conditions for generation or intensification of orographic
precipitation, sometimes responsible by high records and
several social-economical damages. During the winter
2009/2010, some events of heavy precipitation were
observed in Madeira Island, mainly in high regions, as
occurred on 22 December 2009, when intense rainfall was
responsible for economic damages in isolated points of the
island. On the other hand, in the last years, the use of highresolution
simulations are becoming a common tool for
diagnosis and prognosis of intense precipitation events
around the world. Therefore, this study aims at analyzing the
main aspects associated to the generation/enhancement of
precipitation in Madeira Island, verifying the model's ability
for the diagnostic of intense precipitation in a region where
the orographic effects are predominant
IMPACTO DA INTRODUÇÃO DA ALBUFEIRA DE ALQUEVA NO MODELO DE PREVISÃO AROME
Although the floodgates of the Alqueva dam were closed in 2002, giving rise to the largest artificial lake in Western
Europe, its possible effects on the weather in Portugal are not being taken into account by the operational models
of weather forecasting used in IPMA. Thus, it is necessary to introduce the physiography of the lake in the model
under study (AROME), and to validate it by analysing statistically as well as meteorologically the differences
between the model simulations with and without Alqueva and to compare these results with observations
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