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Variabilidade espaço-temporal do material particulado fino (MP2,5) na Bacia Amazônica e sua relação com queimadas e El Niño Oscilação Sul (ENOS)
(Instituto Nacional de Pesquisas da Amazônia - INPA, 2026)
Simões, Samanta Lacerda
;
Souza, Rodrigo Augusto Ferreira de
;
Souza, Rita Valeria Andreoli de
;
Souza, Rodrigo Augusto Ferreira de
;
Medeiros, Adan Sady de
This study analyzed the spatiotemporal variability of fine particulate matter (PM2.5) concentrations in the Amazon Basin between 2003 and 2023, using modeled data from the SatPM2.5 product, fire hotspot data from the MODIS sensor, and the Niño 3.4 index as an indicator of climate variability associated with the El Niño–Southern Oscillation (ENSO). Spatial and temporal patterns of PM2.5 concentrations were eval-uated, as well as trends, change points, and the relative contribution of seasonality, fires, and ENSO to the variability of this pollutant. The results revealed a heteroge-neous spatial pattern, with higher concentrations in the southern and southwestern portions of the basin, especially in areas associated with the arc of deforestation, northern Bolivia, Rondônia, Mato Grosso, southern Amazonas, and southern Pará. The lowest concentrations occurred in the northern and northwestern portions of the basin, where there is less direct influence from the main fire source regions. From a seasonal perspective, a well-defined annual cycle was observed, with lower values between May and July and a marked increase from August onward, reaching maxi-mum concentrations in the ASO quarter, especially in September. The regional anal-ysis indicated that areas more strongly influenced by fires show higher concentra-tions and critical pollution episodes, while central areas, although less associated with local fire sources, may be affected by aerosol transport during years of extreme drought. The trends showed spatially distinct behavior, with increases in the western, southwestern, northwestern, and central sectors of the basin, and decreases in southeastern areas. Multiple linear regression indicated that seasonality and fires are the main explanatory factors of PM2.5 variability, while ENSO exerts a complementary and indirect influence, mainly on interannual anomalies. ENSO also showed a sea-sonally concentrated influence in ASO and NDJ, especially in the northern Amazon Basin, contributing complementarily to the interannual variability of PM2.5. The results reinforce the importance of continuous air quality monitoring and the integration of climate, fire, and environmental management information in the Amazon, to ade-quately protect the region’s vulnerable populations from this growing threat.
Simões, Samanta Lacerda
Fernandes, Karenn Silveira
Variabilidade interanual e tendências das características da estação chuvosa na Amazônia Brasileira: início, término, duração e intensidade
(Instituto Nacional de Pesquisas da Amazônia - INPA, 2026)
Macêdo, Tabata Lauhanda Bastos de
;
Souza, Rita Valeria Andreoli de
;
Souza, Itamara Parente de
;
Brito, Adriane Lima
;
Vergasta, Leonardo Alves
This study analyzed long-term trends and interannual variability in the onset (IEC), demise (FEC), duration, and intensity of the Rainy Season (EC) in the Amazon, relating them to the main modes of climate variability of the tropical oceans. Three regions were considered, Northwestern Amazon (AMNO), Central Amazon (AMC), and Southeastern Amazon (AMSE), from 1980 to 2022. The IEC and FEC were determined using the Antisymmetric Outgoing Longwave Radiation index (AROL), while duration was defined as the number of pentads between the onset and end of the season, and intensity as the accumulated precipitation within that interval. The analyses included trend tests, linear correlations, and box plots, allowing the assessment of the main modes of climate variability of the Pacific, Atlantic, and Indian oceans on the characteristics of the EC. The results showed a delayed IEC trend in AMSE and an earlier trend in AMNO, while AMC remained stable; the FEC, in turn, showed an earlier trend in all three regions. None of these trends showed statistical significance. The duration of the EC also showed no statistically significant trend in any of the regions, although AMSE exhibited the largest rate of reduction among them. Regarding intensity, a significant increase in accumulated precipitation was observed in AMC, while AMNO showed an increasing trend and AMSE a decreasing trend, both without statistical significance. Correlation analyses indicated associations between the EC characteristics and different Sea Surface Temperature (SST) modes of the tropical oceans, with distinct responses among the regions. The box plots showed that the influence of climate variability modes occurs in a combined and regionally differentiated manner. In AMC, greater influence of the Tropical South Atlantic (ATS) was observed on the onset and end of the season, while duration showed greater association with ENSO. In AMNO, interactions between the Pacific and Atlantic oceans stood out in modulating the EC characteristics. In AMSE, joint action of the Pacific, Atlantic, and Indian oceans was observed on the onset, end, duration, and intensity of the rainy season. Overall, the results show that EC variability in the Amazon results from the interaction between different modes of climate variability, producing distinct responses among the regions analyzed.
Vergasta, Leonardo Alves