Effects of atmospheric systems operating in the Northeast of Brazil on the volumes of artificial reservoirs
Abstract This study aims to quantify the impact of rainfall patterns influenced by the seasonal movement of the Intertropical Convergence Zone (ITCZ), Frontal Systems (FS), and South Atlantic Convergence Zone (SACZ) during El Niño, La Niña, and neutral years on reservoirs water volumes across the No...
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| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-07-01
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| Series: | Scientific Reports |
| Subjects: | |
| Online Access: | https://doi.org/10.1038/s41598-024-82858-x |
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| Summary: | Abstract This study aims to quantify the impact of rainfall patterns influenced by the seasonal movement of the Intertropical Convergence Zone (ITCZ), Frontal Systems (FS), and South Atlantic Convergence Zone (SACZ) during El Niño, La Niña, and neutral years on reservoirs water volumes across the Northeast of Brazil (NEB) from 1998 to 2018. Data sources include meridional and zonal components of the winds, outgoing longwave radiation, monthly rainfall, oceanic sea surface temperature, and reservoir volume from the Brazilian National Agency for Water and Basic Sanitation and state departments were used. ITCZ identification employed semi-objective techniques, while CPTEC/INPE reports aided in identifying FS and SACZ. The study calculated reservoir water volume percentages and applied correspondence analysis between volume changes and atmospheric systems during El Niño, La Niña, and neutral years. The results show that when the ITCZ central position during February-May is near (far) equator positive (negative) rainfall anomalies occurred, correlating with increase (decrease) reservoir volumes. El Niño (La Niña) years consistently exhibited negative (positive) rainfall anomalies, with reservoirs volume decreasing (increasing) its water storage. Approximately 17% of FS in Brazil reaches the southern NEB during November-February, with an average of three FS and SACZ cases per season in this region. Increase (decrease) in the reservoirs volume was observed when the FS and SACZ was above average. Overall, although the statistical tests indicates that there was no statistical significance, the correspondence analysis indicated a potential visual connection between the meteorological systems, reservoir volumes and ENSO phases. Furthermore, we highlighted the importance of analyzing other hydrological variables such as evapotranspiration and surface runoff to better comprehend the NEB reservoir recharge dynamics in ENSO phases. |
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| ISSN: | 2045-2322 |