用周期性对流解释表面变暖向双胞模拟沃克环流的转变
Transition to double-cell mock Walker circulations with surface warming explained by periodic convection
AI总结：
研究用周期性对流解释表面变暖时模拟沃克环流从单胞到双胞的转变，冷模拟中暖池由稳定深对流主导形成单胞，热模拟中暖池交替受深对流和层状模式主导形成双胞，揭示变暖时沃克环流强度减弱外还有结构变化及对流对翻转环流的影响。
AI中文摘要：
理想化的模拟沃克环流广泛用于研究热带地区翻转环流与对流之间的相互作用。以往研究表明，当平均海表温度超过300K时，单胞模拟沃克环流会转变为双胞模拟沃克环流。本文将这种转变归因于更强的对流耦合波导致的周期性对流的出现。在冷模拟中，暖池由稳定的深对流主导，形成单翻转胞；在热模拟中，暖池交替由深对流和层状模式主导，分别形成下胞和上胞。研究表明，气候变暖时沃克环流可能不仅强度减弱，还会有复杂的结构变化，凸显了对流对翻转环流的深远影响。
英文摘要：
Idealized mock Walker simulations are widely used to study the interactions between overturning circulation and convection in the tropics. Previous studies documented a transition from a single-cell to a double-cell mock Walker circulation when the average sea surface temperature exceeds 300 K. Here, we ascribe the transition to the emergence of periodic convection with warming due to stronger convectively-coupled waves. In cold simulations, the warm pool is dominated by steady deep convection, which results in a single overturning cell. In hot simulations, the warm pool is alternately dominated by deep convection and a stratiform mode, resulting in lower and upper cells respectively. This study suggests that the Walker circulation in a warmer climate may feature complex structural changes in addition to a weakening in strength, and highlights the profound impacts of convection on overturning circulation.
