Surface warming-driven changes in stratiform heating structure weaken and accelerate convectively coupled Kelvin waves: the role of melting-level rise

not-yet-known not-yet-known not-yet-known unknown Although stratiform heating plays a crucial role in tropical convective systems, it remains unclear (1) how stratiform heating changes with surface warming and (2) how those changes affect convectively coupled equatorial waves. This study analyzes changes in the stratiform heating structure and convectively coupled Kelvin waves (CCKWs) associated with surface warming using a set of aquaplanet simulations (-4K, CTL, +4K). Results show that the melting level rises with warming, causing ice particles falling from the stratiform clouds to melt at lower pressure levels (higher altitudes). The upward shift of melting-induced cooling results in a decrease in temperature and vertical motion variability associated with stratiform clouds in the lower free-troposphere and upper boundary layer. These changes lower the degree to which stratiform (i.e., the second baroclinic mode) and deep convective clouds (i.e., the first baroclinic mode) are coupled within CCKWs, causing CCKWs to weaken and accelerate with warming.