This study uses climate modeling (RegCM4 Climate Model) to provide a wind forecast average behavior at low levels, close to the surface. The model was used to generate an estimate of the average vertical wind profile lasting 5 months, from August to December 2015, attempting to observe intra-seasonal variations, with the presence of persistence in the wind field. The results of climate modeling of the wind profile near the surface have the great potential for great operational significance during launch campaigns at the Centro de Lançamento de Alcântara. Three average results were generated for the month of November 2015, while operating in São Lourenço. A dynamical downscaling nested with global models with RCP4.5 and RCP8.5, using 3 different global conditions initialization datasets. It used subsets with the models from the Met Office Hadley Centre (HadGEM2-ES), the Centre National de Recherches Météorologiques (CNRM-CM5), and the Commonwealth Scientific and Industrial Research Organization (CSIRO-Mk3.6), making a downscaling with the RegCM4 Climate Model for the Centro de Lançamento de Alcântara region. The results are preliminary but show great potential. Since the RegCM4 Climate Model can show variations of high and low intensity, its temporal frequency in the average vertical wind profile and the duration of temporal variation are of the order of 3-5 days. The RegCM4 Climate Model had better results with the one from the Met Office Hadley Centre, HadGEM2-ES, when it was qualitatively compared with observational data (ERA Interim Model) of the campaign period and reanalysis data.

Neste estudo busca-se entender as relações dos Jatos de Nível Baixo (JNB) e dos fluxos no perfil vertical do vento na geração de convecção em escala sinótica e a sua associação com a precipitação, observa-se o perfil vertical do vento através de radiossondagens realizadas no Aeroporto Internacional Salgado Filho em Porto Alegre, Estado do Rio Grande do Sul, Brasil. Estimam-se características predominantes da dinâmica dos fluxos dentro da baixa atmosfera, descrevendo a interação dos JNB e fluxos na geração da precipitação. Os JNB associados neste intenso transporte apresentam uma tendência de estarem ligados a eventos convectivos noturnos e na geração de Sistemas Convectivos de Mesoescala (SCM), que geram elevados índices pluviométricos que podem causar importante influência econômica. Utiliza-se a técnica da Análise das Componentes Principais para realização deste estudo, comparando suas componentes com a precipitação de sessenta e quatro estações pluviométricas sobre Estado do Rio Grande do Sul. O emprego desta metodologia facilita o entendimento da complexidade das interações das diferentes escalas meteorológicas envolvidas nos processos sinóticos de macro e mesoescala, mostrando neste método uma melhor representação das características dinâmicas dos processos baroclínicos na convecção. Em tal complexidade, o trabalho realizado pelos JNB e os fluxos nesta interação são o de serem uma escala efetiva de transporte de vapor de água na baixa atmosfera ao nível de mesoescala e de escala continental.

A ocorrência de Jatos de Nível Baixo (JNB) promove o transporte de propriedades escalares e vetoriais dentro da Camada Limite Planetária (CLP). Neste estudo foi realizada uma investigação da presença desses JNB sobre a região metropolitana de Porto Alegre (RS/Brasil) durante o período de três anos (1995 a 1997) através de dados de vento na vertical registrados por radiossondagens no Aeroporto Internacional Salgado Filho. Os dados coletados possibilitaram caracterizar os valores máximos do vento e suas respectivas alturas definindo a ocorrência e freqüência dos jatos. Para tanto, utilizou-se a metodologia de classificação proposta por Bonner (1968) e modificada por Whiteman et al. (1997) à qual foi agregada uma nova categoria (JNB Fraco). As análises dos resultados obtidos permitiram conhecer-se o comportamento dos JNB e as suas características microclimatológicas sobre a região metropolitana de Porto Alegre.

Global NCEP climate forecast system (CFSv2) was used as initial and boundary conditions for the Regional Climate Model (RegCM4.6) in order to produce intraseasonal forecasts (one month) for Alcântara Launch Center (ALC) in Maranhão State. The forecasts were carried out from June to October 2017 and the wind and air temperature at lower atmosphere were evaluated. For this reason, we used ERA-Interim reanalysis. In the ALC, the RegCM4.6 presented a good performance in representing the monthly means of the variables under study, but in some oceanic regions of the domain, it presented greater deviations.

The objective of this study is to perform a vertical wind profile analysis using radiosonde data at the Alcântara Launch Center (ALC), using the multivariate statistical technique of the Principal Components Analysis (PCA), to verify if there is a presence of flows in the vertical wind profile. These flows may characterize local circulations and be associated with sea breeze-type circulations, and may also be associated with synoptic mesoscale level circulations, such as Low-Level Jets (LLJ). The results showed that in the first three components in the nocturnal period there is a presence of LLJ, with 85% of the variance explained. The occurrence of LLJ presented typical heights in the components, the first one with a height of 800 meters (average direction 60 to 70 degrees), the second with a height of 400 meters (mean direction 40 to 50 degrees) and the third with 200 meters average 50 to 60 degrees). These LLJs may be associated with processes related to the Planetary Boundary Layer (PBL) at night, such as maximum wind inversion and breezes.

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The sensitivity of the planetary boundary layer (PBL) parameterizations is investigated using the hybrid Fifth Generation Penn State University/National Center for Atmospheric Research (NCAR) Mesoscale Model (MM5) and its results were compared with observations from two field campaigns held during the dry and wet seasons at the Centro de Lançamento de Alcântara (CLA). The comparisons were made using the integrated zonal and meridional components of observed and forecasted winds. Initially, three boundary layer parameterizations, in addition to the current parameterization, were selected for evaluation: Blackadar (BLK), Medium Range Forecast (MRF), Janjic (ETA) and Burk-Thompson (BT). The MRF and BLK schemes produced better results than the ETA and BT schemes. Nevertheless, MRF and BLK underestimate the zonal and meridional wind components by around 16% in the rainy season and overestimate them by on average 18% in the dry season.