Temperatura da superfície na cidade de Manaus: uma abordagem usando análises de Funções Ortogonais Empíricas de Tendências

Abstract

This study investigated the spatiotemporal behavior of Land Surface Temperature (LST) in Manaus between 2003 and 2023 and its relationships with vegetation cover, represented by the Normalized Difference Vegetation Index (NDVI), and with precipitation variability induced by anomalies in Sea Surface Temperature (SST) in tropical oceans. Trend Empirical Orthogonal Functions (TEOF) were applied to LST anomalies, along with statistical tests (Mann-Kendall) and linear correlation analyses. Climatological results showed that urbanized areas exhibited higher LST, with maximums reaching up to 41°C in the September-October-November (SON) quarter, while vegetated areas andthose adjacent to water bodies recorded lower temperatures (26–31°C). The TEOF decomposition of monthly LST anomalies identified two main modes. The first mode reflected a widespread warming trend, related to increased tropical SST and reduced precipitation. The second mode displayed a contrasting spatial pattern, with warming in the central and northern regions of Manaus and relative cooling in peripheral zones, associated with the reduction of vegetated areas in the city. This pattern was statistically corroborated by the Mann-Kendall test. On a seasonal scale, the variability patterns identified by the first mode in the December-January-February (DJF), MarchApril-May (MAM), and SON quarters showed a strong association with SST anomalies in the equatorial Pacific Ocean, linked to the El Niño-Southern Oscillation (ENSO), as well as the Atlantic and Indian Oceans. Conversely, the trend patterns identified by the second mode were consistent across all quarters, indicating systematic warming in central areas and relative cooling in the eastern and southwestern parts of the city, primarily associated with reduced vegetation in response to increased urbanization.