Abstract. Forest fire danger rating based on sparse meteorological stations is known to be potentially misleading when assigned to larger areas of complex topography. This case study examines several fire danger indices based on data from two meteorological stations at different elevations during a major drought period. This drought was caused by a persistent high pressure system, inducing a pronounced temperature inversion and its associated thermal belt with much warmer, dryer conditions in intermediate elevations. Thus, a massive drying of fuels, leading to higher fire danger levels, and multiple fire occurrences at mid-slope positions were contrasted by moderate fire danger especially in the valleys. The ability of fire danger indices to resolve this situation was studied based on a comparison with the actual fire danger as determined from expert observations, fire occurrences and fuel moisture measurements. The results revealed that, during temperature inversion, differences in daily cycles of meteorological parameters influence fire danger and that these are not resolved by standard meteorological stations and fire danger indices (calculated on a once-a-day basis). Additional stations in higher locations or high-resolution meteorological models combined with fire danger indices accepting at least hourly input data may allow reasonable fire danger calculations under these circumstances.

Abstract. Forest fire danger rating based on sparse meteorological stations is known to be potentially misleading when assigned to larger areas with a complex topography. This case study examines outputs of several fire danger rating systems based on data from two meteorological stations in different elevations during a major drought period. This drought was caused by a persistent high pressure system, inducing a pronounced temperature inversion with cool, humid conditions in the lower and warmer, dryer conditions in the upper layer. Thus, a massive drying of fuels, leading to a high fire danger level and multiple fire occurrences at higher elevations were contrasted by moderate fire danger in the valleys. The relative accuracy of fire danger rating indices was studied based on a comparison with the actual fire danger as determined from expert observations, fire occurrences and fuel moisture measurements. The results revealed that, during temperature inversion, differences in daily cycles of meteorological parameters influence fire danger and that these are not resolved by standard meteorological stations and fire danger indices. Additional stations in higher locations or high-resolution meteorological models in combination with fire danger indices that accept hourly input data may allow reasonable fire danger calculations under these circumstances.

A energia eólica é, atualmente, uma das fontes de eletricidade que mais crescem em todo o mundo. Porém, especialmente no Brasil, ainda é muito difícil a localização de regiões com ventos confiáveis para a implantação de um parque eólico pois não existe uma densidade de dados válidos que sirvam de garantia de eficiência do parque. Assim, o desenvolvimento de modelos que simulam as condições de vento são extremamente importantes para estudos e pesquisas na área. Neste sentido, dados de reanálises

Aplicação do diagrama de Mudge e QFD utilizando como exemplo a hierarquização dos requisitos para um carro voador

Identification and estimation of the period of non turbulent oscillatory processes in the stable boundary layer through autocorrelation functions