Variações Temporais da Concentração de Ozônio de Superfície

Abstract

The first results of ozone concentration measurements are presented for the region of São José dos Campos. The results show for the first time some of the time variations of the ozone concentration sampled close to the surface. Ozone is a natural gas of the non polluted atmosphere but it has become increasingly difficult finding an ecosystem not affected by artificial elements added to the atmosphere that might interfere with the ozone chemistry. Its presence in the stratosphere is highly desirable for the absorption of UV radiation, but in the troposphere its concentration may become excessive owing to combustion processes, and since it is a toxic gas, may become harmful to life. Surface ozone measurements are presented for several ecosystems showing its diurnal variation. Seasonal and meteorological influences can be seen in a 13 month set of data from São José dos Campos. The concentrations are larger than results from the remote sites Cuiabá (MT), Belém (PA), and Manaus (AM), showing well pronounced diurnal variations, with maximum around noon and minimum close to dawn.