Lopes et al. (2025) Dynamically Downscaled European Water Budget Quantities in the Presence of Sea Surface Temperature Uncertainty

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Hydrometeorology
• Year: 2025
• Date: 2025-12-15
• Authors: Francis da Silva Lopes, Michael Schindelegger, Benjamin D. Gutknecht, Jürgen Kusche
• DOI: 10.1175/jhm-d-25-0018.1

Research Groups

Researchers participating in the European branch of the Coordinated Regional Climate Downscaling Experiment (EURO-CORDEX).

Short Summary

This study investigates how the choice of sea surface temperature (SST) products influences land-based water budget quantities in EURO-CORDEX regional climate simulations. It finds that different SST products lead to notable differences in precipitation and freshwater flux, particularly in heavy precipitation events, and generally improve terrestrial water budget statistics compared to reanalysis-based fluxes.

Objective

• To quantify the influence of different sea surface temperature (SST) products, used as lower boundary conditions, on water budget quantities over land in limited-area atmospheric simulations within the EURO-CORDEX framework.

Study Configuration

• Spatial Scale: European domain, 12 km horizontal resolution.
• Temporal Scale: June 2002 to May 2011 (9 years).

Methodology and Data

• Models used: A reanalysis-forced regional climate model (RCM) configured for the EURO-CORDEX domain.
• Data sources: Three different Sea Surface Temperature (SST) products (including foundation and skin temperatures) as lower boundary conditions; reanalysis data for forcing; observed river discharge; terrestrial water storage changes.

Main Results

• Using foundation temperatures instead of slightly cooler (~-0.2 °C) skin SST increases land-domain-averaged mean annual precipitation ($P_L$) by approximately 2.4%.
• The associated annual freshwater flux ($PL - EL$) increases by approximately 3.9% when using foundation temperatures.
• The spatial spread in simulated precipitation varies, with largest intermodel differences observed in summer over central and eastern Europe and in winter along parts of the Mediterranean coast.
• Differences in $P_L$ are primarily reflected in the intensity of heavy precipitation events, suggesting a significant role for model internal variability triggered by macroscopic SST differences.
• Terrestrial water budgets for 12 river basins show the three SST solutions are generally indiscriminate, except for several eastern European basins (e.g., Dniester, Pripyat).
• Overall, the SST-driven solutions reveal improved budget statistics compared to a solution using reanalysis-based surface freshwater fluxes.

Contributions

• Quantifies the impact of different SST product choices (specifically foundation vs. skin temperatures) on land-based water budget components ($PL$, $PL - E_L$) within EURO-CORDEX simulations.
• Highlights the spatial and seasonal variability of these impacts, particularly on heavy precipitation events.
• Demonstrates that SST differences can trigger significant model internal variability.
• Evaluates the sensitivity of terrestrial water budgets in river basins to driving SST products, showing general improvements over reanalysis-based fluxes.

Funding

Not specified in the abstract.

Citation

@article{Lopes2025Dynamically,
  author = {Lopes, Francis da Silva and Schindelegger, Michael and Gutknecht, Benjamin D. and Kusche, Jürgen},
  title = {Dynamically Downscaled European Water Budget Quantities in the Presence of Sea Surface Temperature Uncertainty},
  journal = {Journal of Hydrometeorology},
  year = {2025},
  doi = {10.1175/jhm-d-25-0018.1},
  url = {https://doi.org/10.1175/jhm-d-25-0018.1}
}