Tang et al. (2025) Radiative–Convective Equilibrium over an Idealized Land Surface with Fixed Soil Moisture

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

Identification

• Journal: Journal of Climate
• Year: 2025
• Date: 2025-09-18
• Authors: Lois I. Tang, Kaighin A. McColl
• DOI: 10.1175/jcli-d-24-0438.1

Research Groups

Not explicitly mentioned in the abstract.

Short Summary

This study uses theory and simulations to understand radiative-convective equilibrium (RCE) over idealized land surfaces with fixed soil moisture, a crucial step for land climate modeling. It finds that potential evapotranspiration primarily scales with surface net radiation, implying only modest increases in global mean aridity with warming, contrary to some prior predictions.

Objective

• To understand the behavior of radiative-convective equilibrium (RCE) over idealized land surfaces with fixed soil moisture, and to explore its implications for hydrological sensitivity, potential evapotranspiration (PET), and changes in aridity in a warming climate.

Study Configuration

• Spatial Scale: Idealized, column-based atmospheric model, with implications for continental and global climate.
• Temporal Scale: Steady-state (equilibrium) conditions, analyzed for long-term climate change scenarios.

Methodology and Data

• Models used: Parsimonious gray gas theory, cloud-permitting simulations of RCE.
• Data sources: Theoretical derivations and idealized numerical simulations.

Main Results

• Over fixed dry surfaces, hydrological sensitivity follows Clausius–Clapeyron scaling, which is considerably greater than the typical 2%–3% K⁻¹ observed over oceans.
• Over fixed saturated surfaces, the theory reconciles divergent explanations for hydrological sensitivity by highlighting the key role of changes in near-surface relative humidity.
• Potential evapotranspiration (PET) is shown to primarily scale with surface net radiation, rather than temperature or vapor pressure deficit, aligning with recent empirical findings.
• The predicted PET scaling suggests only modest changes in global mean aridity with global warming, contrasting with larger increases implied by some previous studies.
• Rainfall increases with warming at a faster rate over fixed dry land surfaces compared to Earth's average.

Contributions

• Extends the idealized radiative-convective equilibrium (RCE) framework to land surfaces with fixed soil moisture, representing a logical advancement in the land climate model hierarchy.
• Develops a parsimonious gray gas theory that accurately reproduces major aspects of cloud-permitting RCE simulations over idealized land surfaces and provides analytic solutions.
• Offers a unified explanation for hydrological sensitivity over saturated surfaces, emphasizing the role of near-surface relative humidity.
• Provides a new theoretical understanding of potential evapotranspiration (PET) scaling with surface net radiation, challenging existing paradigms and suggesting a less drastic increase in global aridity under warming.

Funding

Not explicitly mentioned in the abstract.

Citation

@article{Tang2025RadiativeConvective,
  author = {Tang, Lois I. and McColl, Kaighin A.},
  title = {Radiative–Convective Equilibrium over an Idealized Land Surface with Fixed Soil Moisture},
  journal = {Journal of Climate},
  year = {2025},
  doi = {10.1175/jcli-d-24-0438.1},
  url = {https://doi.org/10.1175/jcli-d-24-0438.1}
}