Apresentação das publicações geradas pela Divisão de Pesquisa relacionadas a Meteorologia Aeronáutica
Severe weather events can affect airport activities and air traffic management, as well as other socioeconomic activities. In this work, for 3 severe weather cases that occurred in the International Airport of São Paulo – Guarulhos between 2016 and 2017, the performance of high resolution simulations with the Weather Research and Forecasting Model (WRF) using multiphysics ensemble was evaluated. In the 3 cases, there was a common synoptic condition: the presence of a frontal system over the region. The number of members in the ensemble was 9. The simulations were performed in two nested domains with 9 km and 3 km horizontal spacing approximately centered at the airport. Initial and boundary conditions were provided by Global Forecast System (GFS) forecasts. The forecast range was 24 h. The analysis of results focused on two variables: precipitation and wind at 10 m. To compare simulations with observations, for precipitation, statistics computed from information contained in a 100 km x 100 km box centered at the airport were used; for wind, values at the grid point closest to the airport were used. The time series for observations were compared with that for simulations by using ensemble metrics (median, dispersion and outlier) represented in boxplot. The results showed that the time of occurrence and the duration of heavy precipitation can be predicted in both domains by outliers. For the maximum precipitation intensity, the value and the time of occurrence can be predicted by outliers in the 9 km domain and the median in the 3 km domain. The time of occurrence and duration of wind gusts can be predicted by the dispersion in both domains. All these results, being valid for all 3 cases, can be regarded as robust. The methodology used in the work, due to its simplicity, can be adapted and implemented in operational centers, such as the Centro Integrado de Meteorologia Aeronáutica (CIMAER), to assist the weather forecasting activities for the International Airport of São Paulo.
In aviation, short-term weather forecast is very important for the planning of air navigation. Recent studies show that data assimilation improves the efficiency of weather forecast models, however it is not properly quantified the impacts of radar data assimilation related to the physical model parameterizations, especially the microphysics. The goal of this study is to perform experiments using 9 different parameterization of microphysics using the Weather Research and Forcasting (WRF) model and its data assimilation system (WRFDA-3DVAR) in a grid with 2 km horizontal resolution. The study area covers the South-western Brazil and Southeastern Paraguay. The simulations were done for October 30th, November 7th and December 13th of 2014, due to the intensity of precipitation, as well as the quality and availability of observational data, i.e., surface, radiosonde and radar data. The comparison is performed through the statistical metrics Fractional Skill Score (FSS) and Local Root Mean Square Error (LRMSE). Different microphysics parametrizations were tested when assimilating conventional and radar data for three events, totalling 81 run of the model. Thus, it is expected to determine the best microphysical parameterization that provides the more realistic short-term forecasts of meteorological fields over the radars area, as well as the relative impact of different microphysical parameterization and the assimilation of conventional and radar data. The positive impact of the radar data assimilation was in the average up to 20% in the FSS, while the positive impact among the microphysics options reached 70% in FSS.
The G3DVAR assimilation system, based in the Gridpoint Statistical Interpolation (GSI), coupled to Atmospheric General Circulation Model (AGCM), is an initiative of CPTEC/INPE (Center for Weather Forecast and Climate Studies) in generate an initial condition that takes into account the model balances and, consequently, be one that also fosters the obtainment of the best forecasts with emphasis on the South America. To obtain the analysis, G3DVAR looks for a great condition that takes into account the observations and short-term forecasts of the model, beyond their errors. The analysis of the humidity fields presents in some cases negative values and humidity values above the saturation value. These solutions are purely numerical and mostly generated in the process of data assimilation and model integration, that is, they don´t correspond at the physical reality and need to be treated during the process of minimizing of the cost function so that they doesn’t be amplified. G3DVAR uses an additional term in the cost function, called moisture constraint. This term has the function of regulate the process of minimizing, taking the solution to humidity values closer to the physical reality. However, this regulation process depends of parameters that control the acting of this additional term. Aiming to identify the values of the moisture constraint parameters used in the process of minimizing of the G3DVAR cost function, that improve the analysis quality and, consequently, the generated forecasts, were realized experiments that varied the value of these parameters, in the month June 2014. The data analysis showed that the grid points with negative humidity values are distributed throughout the atmosphere simulated in the model over the high latitudes of the Southern Hemisphere and tend to spread toward the low latitudes where the value of moisture constraint parameters increases.
Data assimilation combines the information from numerical models and meteorological observations through a physical-statistical process generating the best representation of atmospheric state in a moment of time. The goal of this work is to tune the background error covariance matrix while assimilating Doppler radar data in order to improve the analysis and then the short-term precipitation forecast. The atmospheric model and the assimilation system used are the Weather Research and Forecasting (WRF) and the WRF Data Assimilation (WRFDA) 3D-Var. The domain covers the west of Southern Brazil, including the state of Parana, Santa Catarina and Rio Grande do Sul and part of Paraguay with horizontal resolution of 2-km and 45 levels. The period of study is from October 15 to November 15, 2014, and the evaluation of the precipitation was made by comparing the results from modeling against the Tropical Rainfall Measuring Mission (TRMM) 3B42 data, using statistical index such the Root Mean Square Error (RMSE). The other meteorological fields were also evaluated using the same statistical indice comparing them to the surface observations. Observations of the surface weather stations were used for comparison with the model results with and without radar data assimilation. The selected stations were Curitiba, Bacacheri, Londrina and Foz do Iguaçu. During the assimilation process, the conventional data from Global Telecommunication System was also assimilated. The background error covariance matrix was generated using utility WRFDA applying the NMC method with 03 months of simulations of 24-h starting at 00UTC and 12UTC. The process of generating the matrix B horizontally spreads the information from a specific observation using a recursive filter, and then setting the error covariance matrix background was applied by adjusting the parameters variance scaling related to the intensity at each observation will influence the state variables in the model grid points , and the length scaling, related to the influence of the error in distance scale the values of the grid points of the model state variables, in order to adjust them to the region study, the assimilated data and the weather system studied. Different values of the two parameters were tested and the results based on statistical indicator showed improvements in predicting the location and intensity of precipitation when applied adjustments to the covariance matrix of background error.
This work presents an observational and modeling study of the Intertropical Convergence Zone (ITCZ) features on the central portion of the Tropical Atlantic Ocean. The variabilities of the position, width and mean precipitation (intensity) of ITCZ for 10 years (1999-2008) are obtained objectively from pentad precipitation data. The influence of the ITCZ over three areas with distinct pluviometric behavior in Northeast of Brazil (NEB), for March and April (1999-2008), when ITCZ is located in its southernmost position, is also studied. The sensitivity of the simulated precipitation from the MM5 regional model to different explicit convection schemes, activation of the Grell shallow convection scheme and adjustments in the Kain-Fritsch convective parameterization scheme (KF2) is tested. The adjustments in KF2 comprise changes in the minimum cloud depth necessary to activate deep convection, in the convective trigger function parameters and in the advective and convective time scales. The observational study confirmed previous works on the variability of ITCZ position and showed new aspects on the variability of ITCZ width and intensity. In the monthly scale, the ITCZ width and intensity tend to decrease when ITCZ reaches its southernmost positions (February, March and April). The amplitude of the annual variation is about 7° for the ITCZ position (1°N in April to 8°N in August), 3° for the width (3° in March to 6° in October) and 3 mm.dia-1 for the intensity (10 mm.day-1 in March to 13 mm.day-1 in July). For the interannual variability of March and April, the largest correlation coefficients were found for the relation between the position and width of ITCZ and the precipitation in the northwestern coast of NEB. The modeling study showed that the use of warm rain scheme and Grell shallow convection scheme (together with KF2 shallow convection scheme) led to marked reduction of the simulated precipitation for the central portion of ITCZ. There were also improvements in the simulated precipitation under the following adjustments in the KF2: convective time increase (5400 s) and minimum cloud depth necessary to activate the convection increase (now ranging from 3500 to 7000 m). The inclusion of all the proposed changes not only removed the bias, but also reduced the root mean square error with a gain of 69%, when compared to the control simulation.
DIAS, Marcos Vinicius da Silva. Análise sinótica de um evento extremo ocorrido na cidade do Rio de Janeiro. Artigo técnico MET001. São José dos Campos: Instituto de Controle do Espaço Aéreo (ICEA), 2018.
The study was developed with the objective of making a synoptic analysis for an event extreme event occurred in the area of the Terminal of Rio de Janeiro between February 14 and 15, 2018. In some surface stations 148 mm of rain were registered in 24 hours and surface winds of approximately 100 km / h. The storm's highest severity moment showed a cloud top temperature of -70° C and indicated a reflectivity of the weather radar near 50 dBZ. Top air analysis was carried out to the top (top down) and it was verified that the severe storm was caused by the presence of a surface dug that expanded to the level of 850hpa, near the coast of Rio de Janeiro, associated to a cold front on the surface. A confluence of winds at the 500hpa level contributed to the instability in the middle atmosphere. Finally, the level of 250hpa showed a dug and a subtropical jet giving support to the cold front, in addition to the diffluence of high level winds in southeastern Brazil. This all favored instability in the atmosphere. Rising currents, high relative humidity, confluence of winds and other factors gave rise to cumulonimbus clouds that remained active for a period of more than 6 hours. The radiosonding, on the day of the storm, confirmed through the instability indexes the synoptic characteristics presented above. The results of these forcants and ingredients were the closures of the main airports of the city, besides.
SOUZA, Filipe Menegardo de. Avaliação dos resultados do Ábaco de Harrison no diagnóstico de turbulência no cruzamento da Cordilheira dos Andes. Artigo técnico MET001. São José dos Campos: Instituto de Controle do Espaço Aéreo (ICEA), 2018.
This study was developed with the objective of evaluating the results of Harrison´s Abacus in the identification of the Andes Mountains turbulence between 2016 and 2017. The data on the occurrences of the phenomena were obtained by means of the SIGMET code issued to the SAMF FIR, calculating the total duration and descriptive statistics, with hourly and monthly frequencies. Using the observational data from the METAR code of the airports of Santiago e Mendonza and the wind of the FL180 of the Santo Domingo radiosondes, an hourly analysis of the cases identified in the Harrison´s Abacus was performed. The results pointed out that the method is important tool and can assit the Meteorologist in his evaluation of the weather conditions and weather forecast.
BUENO, Humberto de Campos. Estudo das características do vento associado a nevoeiro na Academia da Força Aérea. Artigo técnico MET001. São José dos Campos: Instituto de Controle do Espaço Aéreo (ICEA), 2016.
This study investigated the relationship between the direction of the wind observed with the occurrence of fog in the Air Force Academy Airport - AFA. Was made a statistical analysis of 81 fog events in 2008, 116 in 2009, 35 in 2010, 61 in 2011 and 76 in 2012. It was also analyzed the 2008-2012 period as a single to find what kind of fog is prevalent, and the wind characteristics associated with the occurrence of this phenomenon. We came to the conclusion that predominates in the region, the radiation fog, especially in calm wind. However, it also observed that, according to the data of the last two years, collected the newly installed weather station, there is a significant contribution of weak wind with component of this (E) associated with advection fog formation in the area of AFA , which can serve as future research object.
ROBERTO, Carlos Eduardo Pacheco. Análise da frequência de ocorrência de teto baixo no Aeroporto de Campina Grande, Paraíba, no período de 2006 a 2015. Artigo técnico MET001. São José dos Campos: Instituto de Controle do Espaço Aéreo (ICEA), 2016.
Issued by the weather stations surface, the height of the estimated information of the cloud base and quantity are very important for air operations. Knowledge of cloudiness at aerodromes is indispensable for the realization of a safe flight as well as for operational planning of airlines. Thus, this study aimed to determine the frequency of occurrence of cloudiness less than 45 dekameters (dam) at the airport in Campina Grande, Paraíba. For this, we used data of Surface Weather Station clouds (EMS) of Campina Grande Airport in the period 2006-2015, registered in proper forms, filed in the Bank of Climatological Data (BDC) of the Institute of Airspace Control (ICEA). The analysis of these data, it was observed that the month of July is the most low ceilings occur in the town, and the slot of 00h00min to 03h00min (local time) the period of highest frequency. During the period, also could see that 30-38 dam is the height range of the cloud base that is more in the airport area and the stratocumulus cloud is the predominant cloud in the ceiling instances less than 45 dam. Thus, the purpose of the study is to serve as an additional tool to assist in decision making for the airport Campina Grande when dealing with operational ceiling.
ROSSETE, Alessandra Carrijo. Avaliação do modelo WRF ICEA para um caso de tempestade severa no Aeroporto Internacional do Galeão. Artigo técnico MET001. São José dos Campos: Instituto de Controle do Espaço Aéreo (ICEA), 2015.
A case of severe storm that occurred entire december 11 and december 12 of 2013 in Galeão International Airport (GLIA) was simulated by the model Weather Research and Forecasting (WRF) installed at the Institute of Airspace Control (ICEA) with the objective of to assess the model's ability to represent precipitation associated with the event. The results indicated that the model underestimated the amount of precipitation in a point, but could well simulate the dynamic and thermodynamic aspects of system and represent, with little differences, the spatial distribution of precipitation.
SIMÕES, Isabelle Delgado da Silva et al.
Ondas de calor (2023) – o ano mais quente da série histórica do Brasil.
In: XXIII Congresso Brasileiro de Meteorologia, 2024, Campinas – SP.
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BECK, Amanda et al.
Acesso a produtos e dados meteorológicos disponibilizados pelo Instituto de Controle do Espaço Aéreo (ICEA).
In: XXIII Congresso Brasileiro de Meteorologia, 2024, Campinas – SP.
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SIMÕES, Isabelle Delgado da Silva et al.
Análise de índices de extremos climáticos para São Paulo.
In: X Simpósio Internacional de Climatologia, 2023, João Pessoa – PB.
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