Atmosphere chemical characteristics determination of different environments in the São Paulo State: a reactive nitrogen species deposition study

Abstract

Variations in the quantity of reactive nitrogen present in various terrestrial environments are closely linked to environmental changes, aquatic and terrestrial ecosystems contamination and biodiversity loss. The knowledge concerning the reactive nitrogen accumulation in the environment presents major gaps and issues such as "how much the increase in reactive nitrogen deposition can interfere on ecosystems functioning" or "how nitrogen cycle interactions and coupling with other cycles such as the C, S and P occurs" emerges. In this way the scientific question that is raised and that we intend to answer with this project is concerned to the concentration and deposition determination of reactive nitrogen chemical species in its inorganic and organic forms, into the atmosphere of some regions of the State of São Paulo. In this research we will seek the determination of atmospheric deposition acquired from diverse chemical species concentration measurements in various sites with different environment characteristics in the State of São Paulo entitling the use of a low-cost sampling system and opening the possibility of replicate the established model for other regions and therefore, to extend the observation area. The chemicals of interest for this research are NH_3, HNO_3, SO_2, HCl measured on the aqueous extract of atmospheric gaseous phase and NH_4^+, NO_3^-, SO_4^(2-), Cl^-, Na^+, Ca^(2+), Mg^(2+) measured on the aqueous extract of the atmospheric particulate phase. We expect to contribute with information that allowed to evaluate the regional vulnerability to changes and possible alteration in the reactive nitrogen species deposition as a consequence of its accumulation and deposition; identify the possible deposition patterns changes (if any) on ecosystem services as well as to provide information that may contribute to the understanding of the atmospheric component of the nitrogen cycle and C and S cycles connection as these changes may affect the climate. (AU)