| Work Detail |
In a new weekly update for pv magazine , Solcast, a DNV company, reports that solar irradiance levels across the Amazon basin were 10% above the long-term average during April and May, reflecting a decade-long trend toward drier conditions in the region. Above-average irradiance in the Amazon Basin during April and May 2025 has highlighted long-term changes in local climate and land use that are altering cloudiness patterns and increasing solar potential. In contrast, much of the rest of the continent experienced marked monthly fluctuations in irradiance due to a sequence of low- and high-pressure systems, which caused flooding in different regions in April and May. These findings come from analyses conducted using the Solcast API . Across the Amazon basin, irradiance levels were 10% above the long-term average during April and May, months that typically mark the end of the tropical wet season. This reflects a decade-long trend toward drier conditions in the region, a phenomenon that has been linked to both deforestation and climate change in general. A detailed analysis of Solcast data for Manaus, in the state of Amazonas, Brazil, shows a weak positive trend in irradiance despite elevated aerosol levels, including haze and smoke from recent fires in the region. Long-term signals also suggest a shift in the pattern of daytime cloudiness. The average duration of cloudy conditions in Manaus has shifted, now occurring after peak solar hours (i.e., fewer clouds during the midday irradiance maximum). This contrasts with Buenos Aires, where no comparable trend is observed, illustrating that the changes we are seeing in the Amazon basin are not evident elsewhere in South America. These findings are not conclusive, but they show that there are multiple ways climate change can modify irradiance profiles. Meanwhile, central South America experienced pronounced variability in irradiance due to intense weather events. In April, southern Brazil, Paraguay, and Bolivia suffered severe flooding, triggered by low-pressure systems extending from the South Atlantic. These systems channeled moist southeasterly winds into the region, causing widespread rainfall, landslides, and a 20% drop in irradiance relative to the monthly average. In May, a strong ridge of high pressure moved into southern Brazil, reversing conditions. Irradiance jumped to 20% above normal as skies cleared and flooding subsided. At the same time, moisture-laden systems moved south, bringing intense rain to northern Argentina. There, the situation was the opposite: torrential rains reduced irradiance by 15%, capping a turbulent two-month period in the region. |
