Impact of wildfires and other sources of greenhouse gases and aerosols in the Metropolitan Region of São Paulo

Abstract

Megacities are key elements in the problem of global warming and climate change. Nevertheless, the impact that these urban agglomerations have on the concentration of atmospheric aerosols and long-lived or short-lived greenhouse gases remains an open question. While densely urbanized regions are sources of pollutants capable of altering the local and even global climate, they are also the most vulnerable places to extreme weather events resulting from such changes. The impact of climate change is even more intense in urban environments and has the potential to affect an extraordinary amount of lives, as cities are home to most of the global human population. In Brazil, the Metropolitan Area of São Paulo (MASP) distinguishes both in terms of population density and importance to national income. Despite the contribution of local human activities in the region being the most analyzed, such as the emission of pollutants by motor vehicles and industries, the impact of external sources of pollutants must also be analyzed. The arrival of these gases with the transport of smoke plumes from wildfires originated from the most diverse places in South America, for example, has not yet been studied, despite the annual occurrence of these events. On that account, the present project proposes to evaluate the concentration of gases such as carbon monoxide, carbon dioxide, methane and nitrous oxide in the MASP originated from fires outside the region using, for this, products from the satellites OCO-2, OCO-3, GOSAT, Sentinel-5P and Terra. In addition, the presence and impact of pyrocumulonimbus clouds in transport episodes will also be evaluated from remote sensing data, since this cloud is capable of injecting smoke at extreme altitudes and its occurrence in South America is still not properly understood. Finally, just as importantly, it is also the objective of this project to understand the consequence of human activities in the MASP for changes in the radiative balance and in the local climate. To achieve this objective, inventories of concentration of gases and aerosols will be examined, including the participation of smoke from fires estimated in this work, and simulations with radiative transfer codes will be performed. (AU)