Determination of ²¹⁰Pb and ⁷Be in Amazon Rainfall - site ATTO

The Amazon region is one of the largest direct sources of organic aerosols into the atmosphere. The size and elementary composition of aerosols particle are important variables that influence its role as Cloud Condensation Nuclei. Although, aerosols are efficiently, removed by precipitation, the long distance transport of just small fraction of Amazonian aerosols may contribute greatly to the global balance of the free troposphere. The research of atmospheric aerosol transport process can be, carried out using natural radionuclides. These radioactivity isotopes can be introduced into the atmospheric as emission from earth's surface, natural radioactivity produced by cosmic radiation; artificial radioactivity introduced by nuclear weapons test, nuclear incident or humanity activity. As radioactivity tracers, radionuclides quickly bind to the surface of aerosols and nuclei. The removal rate of radionuclides from the atmosphere can be determined using aerosols deposition rate. Considering that, the radioactive isotopes are, recognized as a good atmospheric transport tracers and deposition processes, among them stands out the ⁷Be and the ²¹⁰Pb. The long term monitoring of radionuclides ⁷Be and ²¹⁰Pb in atmospheric depositions, provides useful information of their sources, temporal and seasonal variation, deposition rates, atmospheric distributions and mechanism involved in their removal from the atmosphere. Although these radionuclides have distinctly different origins, they are, removed from the atmosphere by similar mechanisms mainly involving wet precipitation, dry precipitation, cosmic ray intensity, vertical and horizontal atmospheric transport, and radioactivity decay. (author)