Variabilidade do perfil vertical de monóxido de carbono sobre a região metropolitana de Manaus e sua relação com as queimadas

Abstract

The present study analyzes the temporal variability of carbon monoxide (CO) over Manaus metropolitan region (RMM) and its correlation with nearby fires based on data obtained by the environmental satellite AQUA, for the period between 2003 and 2020. The study also presents a comparison between CO remote estimates and the measurements performed during an airplane campaign over a forest area in central Amazon, between 2017 and 2021. The results show a well-defined seasonal behavior, with an increase and decrease in mean CO concentrations during dry and wet seasons, respectively. Semi-annual and annual scales represent around 95 % of CO temporal variability in lower troposphere (500 to 925 hPa) and are associated with rains and fires dynamics in the region. In terms of interannual variability, multiple variability scales were observed, with 1,2-2, 2,5-3 e 4,5-6 years periods, which explain around 10-15 % of concentration variability near surface.The results suggest that climatic variations, associated with tropical Pacific and Atlantic sea surface temperatures variations, on these different time scales, affect rain dynamics and, consequently, fires and CO concentration. Specifically, in 2015/16, the combined effect from different variability scales acted to prolong the dry period over the region, which contributed to increase fires and for the CO to reach higher values compared to previous years. These results show a new aspect about the importance of evaluating the combined effect of different climate variability scales on CO concentrations in atmosphere. Finally, comparisons between AIRS soundings and aircraft measurements reveals good harmony for carbon monoxide profiles, with the sounder being able to detect monthly and seasonal variations displaying a difference lower than 10 ppb in relation to in situ data.