Abstract Observations and climate models show a strong increase/decrease of tropical low clouds, and hence reflected solar radiation, in response to an increase/decrease of the west‐east sea surface temperature (SST) gradient in the tropical Pacific due to its impact on boundary layer inversion strength. Here, we discuss an accompanied increase/decrease of outgoing longwave radiation due to the contraction/expansion of the tropical deep convection area (decreasing/increasing the high cloud amount and relative humidity) when the SST gradient between regions with high and low SST increases/decreases. In targeted amip‐piForcing style GFDL‐AM4 model simulations, the negative longwave radiation response due to large‐scale convective aggregation resulting from the La‐Nina‐like warming pattern over the period 1980–2010 is comparable to the negative shortwave cloud feedback. CMIP6 models show that the multi‐model‐mean is similar to that in our simulations. However, the relative magnitude of shortwave and longwave effects differs substantially between models, revealing an underappreciated climate model uncertainty.
Observations from the Little Bunker
Last updated: October 16, 2025 02:57 AM
Atmospheric CO₂
424.4 ppm
+18.2
ppm/year
Atmospheric CH₄
1933.54 ppb
+12.29
ppb/year
Global Temperature
+1.48 °C
Peak: +1.73°C
World Population
8.1 billion
+67
million/year