Analysis of Radiation, Precipitation and Temperature Considering the Aerosols Simulated by the BAM Model

Atmospheric aerosol is defined as a collection of solid or liquid particles suspended in the atmosphere, which influences the planet's climate through its effect on the radiative balance. Its effects can be direct or indirect. However, the effect of the aerosol is still uncertain, which makes it the center of much scientific research. The direct and indirect effects of the aerosol result in negative forcing, on average, causing the atmosphere to cool, as opposed to greenhouse gases. The aerosol direct effect is observed in the interaction with radiation, absorbing or reflecting radiation. The absorption of radiation by the aerosol causes changes in the thermodynamic balance of the atmosphere, due to its effect on adiabatic heating. It causes a cooling of the atmosphere near the surface, and heating above, which establishes a stable layer, reduces the exchange of sensible, and latent heat, and it may contribute to the reduction of cloud formation (effect semi-direct). The indirect effect of aerosols on weather occurs through the interaction of aerosols with clouds, and causes cooling, in general. The aerosol acts as a basis for condensation and formation of droplets called Cloud Condensation Nuclei (CCN). The CCNs alter the formation of droplets, and ice crystals, interact with radiation, and influence the optical properties of clouds, alter cloud cover, and precipitation. Thus, this work aims to analyze the average monthly temperature, radiation, and precipitation taking into account the effect of atmospheric aerosols. The analyses will be carried out for different cities in Brazil, located in different regions through simulations of the Brazilian Atmospheric Model, the BAM, for the period from 2017 to 2021. This study used the new version of the Brazilian Global Atmospheric Model (BAM) version 2.2.1, the BAM-2.2.1 developed in the CPTEC. BAM is a hybrid model with a horizontal resolution of approximately 1.0 ° x 1.0 ° and 42 vertical sigma levels, 32 levels in the troposphere and 10 in the stratosphere. The BAM simulations will be analyzed in three stages: 1) Constant aerosol (fixed); 2) Aerosol changing monthly (climatological); 3) Zero aerosol. The BAM model simulation will be compared with the MERRA2 (Modern-Era Retrospective Analysis for Research and Applications) reanalysis from NASA.