Abstract's details
SWOT Validation over the Amazon Basin
Event: 2025 SWOT Science Team Meeting
Session: Hydrology: River Science Working Group
Presentation type: Poster
The Amazon Basin experiences extreme hydrological variability, with annual water level fluctuations often exceeding 16 meters. These seasonal changes shape not only the lives and economy of millions across the region but also the local ecology. When more severe than expected, such events can isolate communities, disrupt wildlife habitats, cause economic losses, and lead to shortages of essential supplies. To mitigate these risks, institutions like the Geological Survey of Brazil (SGB) continuously monitor the basin, forecasting the magnitude of annual flood and drought peaks. However, the existing in-situ network lacks the spatial density needed to cover this vast area of approximately 7 million km².
To expand monitoring capacity, SGB, IRD, and partners—with support from CNES—have been leveraging satellite-based observations. In this context, SWOT represents a major opportunity. Recent results (Moreira et al., 2025) have demonstrated SWOT’s strong potential for capturing extreme events, such as the severe 2023 Amazon drought. Recognizing SWOT’s importance for operational hydrological monitoring, SGB, IRD, and collaborators have conducted an extensive validation program. Since May 2023, during SWOT’s Cal/Val phase, field campaigns using GNSS have been collecting water surface elevation (WSE) data. These efforts include evaluations at both pixel cloud and river product levels, focusing on accuracy, uncertainty, and product limitations.
This work presents key validation results, including direct comparisons between SWOT-derived WSE and GNSS measurements, as well as cross-comparisons with continuous in-situ monitoring and other satellite altimetry missions (e.g., hydrologyfromspace.org/hfs-app). The goal is to assess SWOT’s integration potential with both conventional and satellite-based hydrological networks, offering insights into data quality, uncertainties, known issues, and possible solutions to improve future SWOT products.
references:
Moreira, D., Papa, F., Fassoni‐Andrade,A., Fleischmann, A., Wongchuig, S.,Paiva, R., et al. (2025). Widespread and exceptional reduction in river water levels across the Amazon Basin during the 2023extreme drought revealed by satellite altimetry and SWOT. Geophysical Research Letters, 52, e2025GL116180.https://doi.org/10.1029/2025GL116180
Back to the list of abstractTo expand monitoring capacity, SGB, IRD, and partners—with support from CNES—have been leveraging satellite-based observations. In this context, SWOT represents a major opportunity. Recent results (Moreira et al., 2025) have demonstrated SWOT’s strong potential for capturing extreme events, such as the severe 2023 Amazon drought. Recognizing SWOT’s importance for operational hydrological monitoring, SGB, IRD, and collaborators have conducted an extensive validation program. Since May 2023, during SWOT’s Cal/Val phase, field campaigns using GNSS have been collecting water surface elevation (WSE) data. These efforts include evaluations at both pixel cloud and river product levels, focusing on accuracy, uncertainty, and product limitations.
This work presents key validation results, including direct comparisons between SWOT-derived WSE and GNSS measurements, as well as cross-comparisons with continuous in-situ monitoring and other satellite altimetry missions (e.g., hydrologyfromspace.org/hfs-app). The goal is to assess SWOT’s integration potential with both conventional and satellite-based hydrological networks, offering insights into data quality, uncertainties, known issues, and possible solutions to improve future SWOT products.
references:
Moreira, D., Papa, F., Fassoni‐Andrade,A., Fleischmann, A., Wongchuig, S.,Paiva, R., et al. (2025). Widespread and exceptional reduction in river water levels across the Amazon Basin during the 2023extreme drought revealed by satellite altimetry and SWOT. Geophysical Research Letters, 52, e2025GL116180.https://doi.org/10.1029/2025GL116180