Influência da queima de biomassa nos transportes de gases e chuva na Amazônia Central

Abstract

The objective of this thesis is to investigate how the mesoscale convective systems and fluvial breeze circulation act in the central Amazon region in a scenario of pollution caused by biomass burning in the dry period of 2014. This investigation was carried out through numerical modeling with the Weather Research and Forecast coupled with Atmosphere Chemistry (WRF-Chem). It was investigated, through a case study of a mesoscale convective system (MCS) that occurred in the central Amazon region on August 16th, 2014, how pollution from biomass burning can alter this MCS. For this, simulations with two scenarios was taken, one considering biomass burning (bb_on) and another without biomass burning (bb_off). The results showed that the bb_on scenario had important consequences on the formation of convective clouds and their downdrafts, being observed with less developed clouds and lower precipitation rates than for the bb_off simulation. It was also observed that the weakening of the convective system showed a lower ability to "clean" the environment, that is, to dilute vertically and horizontally the local concentrations of gases such as carbon monoxide. When analyzing the occurrence of the river breeze during the period from August 1st to 5th, 2014, it was found that the breeze occurred for two days in two different places: in an environment with a contrast between the river and the forest, and in an environment with contrast of the river with the urban region of the city of Manaus. The results showed that during the river breeze events, it was observed that the breeze was responsible for trapping gases such as ozone carbon monoxide on the bank where they occurred (east bank of the Negro River) in both regions. The more intense river breeze had its duration longer, in addition to keeping the gases in an area within the continent, when compared to a less intense breeze, it trapped these gases within the river area. Additionally, the region in which the river breeze was responsible for concentrating the largest amount of gases is a predominantly residential region (western portion of the city of Manaus), while the eastern portion (industrial region) was favored by the cleaning of the environment through the trade winds.