The Impacts of Changes in Land Use/Land Cover and Increases in Greenhouse Gases on the Surface Energy Balance During the Rainy Season in the Metropolitan Region of Manaus

Impactos das Mudanças da Cobertura do Solo e Aumento dos Gases do Efeito Estufa no Clima da Região Metropolitana de Manaus

Abstract

This study analyzed the impact of land use and land cover (LULC) changes and increased in greenhouse gases (GHGs) on surface variables in the climate of the metropolitan region of Manaus (MRM). The numerical experiments were carried out using the BRAMS regional model for the MRM rainy season period and divided into four categories, namely: actual land cover, sensitivity to deforestation and urbanization expansions, sensitivity to increased GHGs, and a combined experiment driven by an extreme scenario. Changes in LULC produced local alterations in the energy and radiation balances and in surface temperature. In addition, the diurnal cycle of the precipitation showed an increase after peak hours over the urban area. In the scenario of increasing GHGs, significant changes in the components of the radiation and energy balances resulted in a positive surface temperature anomaly (∼10 °C) and a negative precipitation anomaly (∼50%). These changes were slightly intensified in the combined experiment. It was found that MRM's climate is more sensitive to an increase in GHGs than to a local change in LULC. Our results reinforce the urgent need to take measures to contain the global increase in GHGs because, in the face of such a scenario, the maintenance of the forest, its ecological processes, and its environmental services would be impossible.

Keywords
climate sensitivity; deforestation; urbanization; LULC; BRAMS; The Amazon