资源环境科技发展态势分析平台

Climate models project tropical warming is amplified aloft relative to the surface in response to increased CO₂. Here we show moist adiabatic adjustment overpredicts the multi‐model mean 300 hPa temperature response by 16.6‐‐25.3% across the CMIP5 model hierarchy. We show three mechanisms influence overprediction: climatological large‐scale circulation, direct effect of increased CO₂, and convective entrainment. Accounting for the presence of a climatological large‐scale circulation and the direct effect of CO₂ reduces the CMIP5 multi‐model mean overprediction by 0.7‐‐7.2% and 2.8‐‐3.9% respectively, but does not eliminate it. To quantify the influence of entrainment, we vary the Tokioka parameter in aquaplanet simulations. When entrainment is decreased by decreasing the} Tokioka parameter from 0.1 to 0, overprediction decreases by 9.6% and 10.4% with and without a large‐scale circulation, respectively. The sensitivity of overprediction to climatological entrainment rate in the aquaplanet mostly follows the predictions of zero‐buoyancy bulk‐plume and spectral‐plume models.