Feldl et al. (2025) Explaining the Transient and Equilibrium Longwave Feedback with Moist Adiabatic Theory and Its Deviations

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

Identification

• Journal: Journal of Climate
• Year: 2025
• Date: 2025-12-16
• Authors: Nicole Feldl, Jing Feng, David Paynter
• DOI: 10.1175/jcli-d-25-0228.1

Research Groups

Not available from the abstract.

Short Summary

This study develops a theoretical framework to understand how patterns of surface temperature change influence the global longwave clear-sky radiative feedback, revealing that the pattern effect is driven by distinct regional physical processes, primarily involving surface temperature and relative humidity feedbacks.

Objective

• To develop a theoretical basis for the pattern effect as it relates to the longwave clear-sky feedback and to understand how patterns of surface temperature change influence the global radiative feedback.

Study Configuration

• Spatial Scale: Global, with specific focus on geographic regions including the subtropics, Southern Ocean, high latitudes, and low latitudes.
• Temporal Scale: Transient climate change and equilibrium climate states.

Methodology and Data

• Models used: Climate model simulations forced by transient and equilibrium patterns of sea surface temperature change (specific model names not provided). A moist adiabatic feedback framework was developed and applied.
• Data sources: Model simulations.

Main Results

• The pattern effect on longwave clear-sky feedback is driven by different physical processes in different geographic regions.
• In the subtropics, a more stabilizing feedback under transient climate change is attributed to a more negative relative humidity feedback.
• Over the Southern Ocean, a less stabilizing feedback under transient climate change results from muted surface warming, leading to a weak surface temperature feedback.
• For an idealized forcing where transient sea surface temperature change is uniformly increased while retaining its structure, the pattern effect essentially disappears.
• The moist adiabatic feedback framework demonstrates that the evolving zonal-mean longwave clear-sky feedback (stabilization at high latitudes, destabilization at low latitudes as climate approaches equilibrium) is controlled by surface temperature and relative humidity feedbacks, which are not isolated by conventional feedback analysis.
• Globally, the destabilization effect is larger, with additional contributions from small but geographically extensive differences in the fixed relative humidity atmospheric temperature feedback.

Contributions

• Presents a novel theoretical basis for the pattern effect specifically concerning the longwave clear-sky feedback.
• Introduces a new moist adiabatic feedback framework that partitions feedback components, offering a more detailed understanding than conventional analyses.
• Identifies that surface temperature and relative humidity feedbacks are critical, previously unisolated processes controlling the evolving zonal-mean longwave clear-sky feedback.

Funding

Not available from the abstract.

Citation

@article{Feldl2025Explaining,
  author = {Feldl, Nicole and Feng, Jing and Paynter, David},
  title = {Explaining the Transient and Equilibrium Longwave Feedback with Moist Adiabatic Theory and Its Deviations},
  journal = {Journal of Climate},
  year = {2025},
  doi = {10.1175/jcli-d-25-0228.1},
  url = {https://doi.org/10.1175/jcli-d-25-0228.1}
}