Work

Estimating Tropical Upper‐Level Cloud Feedback Based on Radiative‐Convective Equilibrium Framework

Year: 2025

Type: article

Abstract: Tropical upper‐level cloud (TUC) feedback remains highly uncertain because TUC fraction and its radiative effect respond in complex ways to sea surface temperature (SST) warming. Using a radiative–convective equilibrium (RCE) model, we isolate the radiative impact of TUC changes by adjusting the relative occurrence of clouds and water vapor across the tropics. The resulting TUC feedback parameter, estimated from RCE experiments with observationally constrained versus CMIP6‐derived TUC fractions, is more negative for observational inputs (−1.66 to −1.24 W m −2 K −1 ) and spans a much broader range for CMIP6 inputs (−1.34 to +1.78 W m −2 K −1 ). The stronger negative feedback with observational inputs likely reflects a larger reduction in TUCs with SST warming. In contrast, CMIP6‐based parameters indicate weaker radiative effects of SST‐driven TUC reductions, suggesting that climate models may underestimate this negative feedback.

Source: Geophysical Research Letters

DOI: 10.1029/2025gl118688

Authors: Hyoji Kang, Yong‐Sang Choi

Institution: Ewha Womans University

Language: English

Topic: Climate variability and models

Subfield: Global and Planetary Change

Field: Environmental Science

Domain: Physical Sciences

SDG: Climate action

Open Access status: gold

Estimated APC paid: $3,190