Corbetta et al. (2026) Modeling Spatio-Temporal Surface Elevation Changes in Argentino and Viedma Lakes, Patagonia, Employing ICESat-2

Identification

• Journal: Remote Sensing
• Year: 2026
• Date: 2026-03-25
• Authors: Federico Suad Corbetta, María Eugenia Gómez, Andreas Richter
• DOI: 10.3390/rs18070993

Research Groups

• Centro de Meteorología Espacial, Atmósfera Terrestre, Geodesia, Geodinámica, Diseño de Instrumental y Astrometría (MAGGIA), Universidad Nacional de La Plata, Argentina
• Centro Científico Tecnológico La Plata, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Argentina
• Institut für Planetare Geodäsie, Technische Universität Dresden, Germany

Short Summary

This study develops and validates operational models for spatio-temporal surface elevation changes in Argentino and Viedma Lakes, Patagonia, using ICESat-2 laser altimetry data. The models accurately separate water volume changes, atmospheric forcing effects (wind and air pressure), and geoid contributions, significantly reducing elevation variability and demonstrating ICESat-2's capability for high-precision water resource monitoring in data-sparse regions.

Objective

• To develop operational models of spatio-temporal lake-level variations in Lago Argentino and Lago Viedma, Patagonia, using ICESat-2 satellite laser altimetry as an observational basis.
• To provide precise corrections for hydrological loading effects for geodetic and gravimetric applications.

Study Configuration

• Spatial Scale: Lago Argentino (surface area: 1330 km²) and Lago Viedma (surface area: 1200 km²) in Southern Patagonia, Argentina.
• Temporal Scale:
  • ICESat-2 ATL13 data: November 2018 to December 2023.
  • ICESat GLAH06 data (for validation): March 2003 to October 2008.
  • SWOT Level 2 Water Mask Raster Image Data Product (for preliminary validation): July 2023 to February 2024.
  • ERA5 reanalysis data: Hourly fields for the ICESat-2 observation period.

Methodology and Data

• Models used:
  • Operational lake-level variation model: Superposition of (i) time-averaged lake-level topography (refined geoid model + mean atmospheric effects), (ii) temporally varying water-volume changes, and (iii) static hydrodynamic response to instantaneous wind stress and air-pressure forcing.
  • Preliminary geoid model: Based on SGG-UGM-2 (up to degree and order 300) combined with Residual Terrain Modeling (RTM).
  • Inverse-barometer (IB) effect model: Hydrostatic response to air-pressure changes, conserving water volume.
  • Wind-driven tilt model: Empirically derived transfer functions relating lake-level change to ERA5 wind fields, with an efficiency coefficient and build-up period.
  • Iterative refinement procedure: Lake-level residuals from ICESat-2 are spatially averaged, smoothed, and added to the preliminary geoid model to yield a refined geoid model, which then improves wind corrections.
• Data sources:
  • Satellite altimetry: ICESat-2 ATL13 (along-track water surface heights, 0.7 m spacing, 35 m/130 m segment length for strong/weak beams), ICESat GLAH06 (70 m footprint, 170 m spacing), SWOT Level 2 Water Mask Raster Image Data Product (250 m nominal ground resolution).
  • In situ observations: Daily tide gauge records from El Calafate (Lago Argentino) and Bahía Túnel (Lago Viedma), resolution 1 cm.
  • Atmospheric reanalysis: ERA5-Land (hourly wind speed/direction at 10 m, 0.1° × 0.1° resolution), ERA5 (hourly atmospheric pressure at sea level, 0.25° × 0.25° resolution).
  • Topographic data: SRTM90 Digital Elevation Model (DEM), Southern Patagonian Icefield ice thickness model, bathymetric models (Lago Argentino seismic survey, Lago Viedma sonar/seismic).

Main Results

• ICESat-2 ATL13 elevation measurements show a standard deviation of 106 cm for Lago Argentino and 70 cm for Lago Viedma before corrections.
• The standard deviation of ICESat-2 ATL13 elevations on calm days (wind speeds below 2 m/s) is below 2 cm, demonstrating high precision.
• Application of the full spatio-temporal lake-level variation model reduces the standard deviation of ICESat-2 elevations to 8 cm for Lago Argentino and 14 cm for Lago Viedma.
• Wind efficiency coefficients were determined as 7.93 × 10⁻⁴ s/km for Lago Argentino (optimal build-up period: 4 hours) and 4.43 × 10⁻⁴ s/km for Lago Viedma (optimal build-up period: 7 hours).
• The refined geoid models reveal a concave curvature across the principal lake axis and an intense, localized slope rising towards the Southern Andes, located further west than current geoid models predict.
• Validation with independent SWOT data showed a reduction in residual elevation variability from 18 cm to 3 cm for Lago Argentino and from 16 cm to 6 cm for Lago Viedma, outperforming static geoid models.
• The models provide ellipsoidal reference elevations for the tide gauges: El Calafate (Lago Argentino) at 188.78 m and Bahía Túnel (Lago Viedma) at 265.44 m above WGS84 ellipsoid.
• Correction for wind tilt and crustal deformation significantly impacts water mass estimates from tide gauges, e.g., Lago Argentino water mass decreases by -5.1 × 10⁻³ Gt/a relative to the tide-gauge record, while Lago Viedma water mass increases by +8.6 × 10⁻³ Gt/a.
• Residual variability after all corrections is primarily attributed to unmodeled short-wavelength variations, mainly surface waves, which are more pronounced in Lago Viedma due to stronger winds and longer fetch.

Contributions

• Development of the first operational, spatio-temporal lake-level variation models for Lago Argentino and Lago Viedma, moving beyond static mean lake-surface topography models.
• Demonstrated the unprecedented capability of ICESat-2 for high-accuracy (sub-2 cm on calm days) water resource monitoring in a challenging, data-sparse region of Southern Patagonia.
• Provided a robust methodology for separating temporal (water volume, atmospheric forcing) and spatial (geoid) contributions to lake-level variability, crucial for geodetic and gravimetric applications.
• Refined local geoid models for the lakes, revealing detailed features like concave curvature and localized slopes, improving upon existing global and regional geoid models.
• Quantified the impact of wind-driven tilt and inverse-barometer effects on lake levels and enabled the correction of tide gauge records for local atmospheric and crustal deformation effects, improving water mass balance estimates.
• Established a foundation for multi-mission altimetry calibration and future hydrodynamic modeling refinements, particularly regarding surface waves.

Funding

• Argentine Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación (project no. 01-PICT-2023-02-00007)
• CONICET (project no. 11220200102919CO)
• CONICET doctoral scholarship (for F.S.C.)

Citation

@article{Corbetta2026Modeling,
  author = {Corbetta, Federico Suad and Gómez, María Eugenia and Richter, Andreas},
  title = {Modeling Spatio-Temporal Surface Elevation Changes in Argentino and Viedma Lakes, Patagonia, Employing ICESat-2},
  journal = {Remote Sensing},
  year = {2026},
  doi = {10.3390/rs18070993},
  url = {https://doi.org/10.3390/rs18070993}
}