"A study published on January 25 in the journal Science shows how the presence in the atmosphere of ultrafine aerosol particles (less than 50 nanometers in diameter) can intensify the cloud formation process and rainfall in the Amazon region.
According to the authors of the article, these nanoparticles have always been thought too small to play a significant role in regulating the hydrologic cycle. While this is indeed the case in polluted areas such as European and US cities, or São Paulo in Southeast Brazil, their role in the Amazon is different.
"We never understood how these huge downpours could occur so frequently in the Amazon if the region has few cloud condensation nuclei - around 300-350 particles per cubic centimeter [São Paulo, for example, has as many as 10,000-20,000]. The reason is that we'd never considered the role of these ultrafine aerosol particles," said Paulo Artaxo, a professor at the University of São Paulo's Physics Institute (IF-USP) and co-author of the study.
According to another author of the study, Brazil's National Space Research Institute (INPE) researcher Luiz Augusto Toledo Machado, one of the work's main contributions is to enhance the accuracy of climate models and weather forecasting. "The discovery lets us understand better how urban pollution affects the processes relating to the formation of convective storms in the Amazon," he said.
The investigation began in 2014 and was conducted under the aegis of the Green Ocean Amazon scientific campaign (GOAmazon ).
The São Paulo Research Foundation (FAPESP) supported the study that has just been published through three projects - one led by Henrique de Melo Jorge Barbosa, also a professor at IF-USP, the other one by hPaulo Artaxo, and a third led by Machado.
According to Barbosa, the data used in the article was collected in March-April 2014, during the rainy season, when...(Continuar Lendo)Ultrafine aerosol particles intensify rainfall in Amazon region