Cisalhamento do Vento no Aeroporto Internacional de São Paulo: Aspectos Observacionais e de Modelagem

Resumo Este trabalho visa abordar conceitos e efeitos do cisalhamento do vento, também conhecido como cortante do vento, tesoura de vento ou, em inglês, windshear (WS) e verificar a eficiência do modelo atmosférico WRF para simulação deste fenômeno. O estudo é dividido em duas partes, sendo uma observacional e outra de simulação computacional. A primeira consiste em identificar, através de estudos quantitativos, a ocorrência de tais eventos nas proximidades do Aeroporto Internacional de São Paulo em Guarulhos, utilizando-se de dados de perfil de vento obtidos pelo SODAR (SOnic Detection And Ranging), durante o período de 01 de janeiro de 2016 a 09 de junho de 2017. Foram utilizados dados de velocidade e direção do vento obtidos da superfície até 520 m (aproximadamente 1700 ft) acima do solo e, com isso, foi feita uma análise estatística destas informações. A segunda parte consistiu em reproduzir as ocorrências de cisalhamento do vento no aeroporto em questão, através de 4 experimentos computacionais pelo modelo WRF. Obteve-se resultados próximos das observações em 2 deles, que se mostraram eficientes para prever a ocorrência da cortante do vento para os níveis de altura mais baixos, com antecipação aproximada de 11 a 13 h.

Operational concept and validation of a new airport low-level wind information system

Pilots are sometimes not provided with sufficient information to avoid go-arounds or other operational disruptions that result from low-level wind disturbances. We identified issues with existing windshear alerting systems and developed three types of airport low-level wind information systems to enhance pilot situational awareness of wind conditions by providing landing aircraft with quantitative and visualised wind information for ultimately mitigating air service disruptions due to low-level wind disturbances. The three systems, Airport Low-level Wind Information (ALWIN) and Low-level Turbulence Advisory System (LOTAS), both of which use Doppler radar/lidar, and Sodar-based Low-level Wind Information (SOLWIN), which uses Doppler SOnic Detection And Ranging (SODAR), have different costs and capabilities that allow the most cost-effective system to be selected for an airport according to its scale and local weather characteristics. This paper presents the operational concepts of our newly developed airport low-level wind information systems and describes their validation.

Configuration of Statistical Postprocessing Techniques for Improved Low-Level Wind Speed Forecasts in West Texas

The wind energy industry needs accurate forecasts of wind speeds at turbine hub height and in the rotor layer to accurately predict power output from a wind farm. Current numerical weather prediction (NWP) models struggle to accurately predict low-level winds, partially due to systematic errors within the models due to deficiencies in physics parameterization schemes. These types of errors are addressed in this study with two statistical postprocessing techniques—model output statistics (MOS) and the analog ensemble (AnEn)—to understand the value of each technique in improving rotor-layer wind forecasts. This study is unique in that it compares the techniques using a sonic detection and ranging (SODAR) wind speed dataset that spans the entire turbine rotor layer. This study uses reforecasts from the Weather Research and Forecasting (WRF) Model and observations in west Texas over periods of up to two years to examine the skill added to forecasts when applying both MOS and the AnEn. Different aspects of the techniques are tested, including model horizontal and vertical resolution, number of predictors, and training set length. Both MOS and the AnEn are applied to several levels representing heights in the turbine rotor layer (40, 60, 80, 100, and 120 m). This study demonstrates the degree of improvement that different configurations of each technique provides to raw WRF forecasts, to help guide their use for low-level wind speed forecasts. It was found that both AnEn and MOS show significant improvement over the raw WRF forecasts, but the two methods do not differ significantly from each other.

Estimating the Wind-Generated Wave Erosivity Potential: The Case of the Itumbiara Dam Reservoir

The impact of wind waves is a process that affect reservoir shorelines, causing economic and environmental damage. The objective of this paper is to analyze the erosive potential of waves generated by winds at the shoreline of a large tropical reservoir of the Itumbiara Dam that stands along the Paranaiba River in the Midwest of Brazil. A GIS-based analysis was carried out using a wave fetch model tool (WAVE) developed by the US Geological Survey with wind data from a Doppler sensor (SODAR—SOnic Detection and Ranging) and an ultrasonic anemometer. A wave erosivity potential map was generated combining 16 fetch rasters from every 22.5° wind directions and was weighted according to its corresponding wind frequency over the rainy season. This result showed the critical areas which may have a high wave potential to increase sediment detachment along the reservoir shoreline. Finally, some of these high erosivity potential areas coincide with large erosions sites, which are detected by satellite imagery. This technique was capable of identifying the wave potential which can cause shoreline erosions and also contribute to reservoir management and support future works, including field experimental programs and shoreline erosion treatments.

Conceptual model for runway change procedure in Guarulhos International Airport based on SODAR data

ABSTRACTIn this work, we qualify and quantify the advantages of using SODAR (sonic detection and ranging) from current scenarios of Aeronautical Meteorology, with the goal of establishing a conceptual model for runway change procedures at Guarulhos International Airport (São Paulo, Brazil). The methods consist of analysing data from the Department of Airspace Control (DECEA) and Brazilian Airport Infrastructure (Infraero) about the reports of runway changes in Guarulhos in addition to SODAR data from September 2011 and December 2013. It is noted that in 234 analysed cases of runway change, there were significant periods of weak-intensity wind on the surface as well as the anticipated modification wind direction at altitude detected by sonic detection and ranging (SODAR), indicating future changes in levels closer to the surface. By examining the intersection of both scenarios, it is possible to observe that there is enough time for the air traffic controller to anticipate the needed runway change while minimising the impact on the aircraft flow, and this period has an average duration of 1 hour and 24 minutes. This confirms that the preliminary analysis of the information provided by SODAR can help predict alterations in wind direction, requiring redirection and bringing advantages in economic and security terms.