Convective Couplings With Equatorial Rossby Waves and Equatorial Kelvin Waves: 3. Variations of Clouds and Their Radiative Effects

Utilizing spaceborne cloud radar and lidar (CloudSat/CALIPSO) observation products, we examine vertical distributions of clouds and quantify their radiative effects associated with equatorial Rossby and Kelvin waves. The most important result is that the radiative heating substantially increased the generation of the eddy available potential energy by 19% and 40%, in Rossby and Kelvin waves, respectively, adding to the convective latent heating. Composite analyses indicate a simultaneous development between deep‐convective anvil clouds and stratiform clouds of mesoscale convective systems in the Rossby waves, and a transition from low‐level clouds, anvil clouds to stratiform clouds in the Kelvin waves. These are consistent to precipitation characteristics provided by precipitation radar observation, and thus the apparent heat source can be estimated by combining convective heating and radiative heating. Plain Language Summary Radiative forcing is a key issue in coupling mechanisms between equatorial waves and convective activity in the tropical meteorology. While many previous idealized studies suggested some instability mechanisms, cloud distributions and radiative heating effects associated with convectively coupled equatorial waves are not enough investigated. We utilize spaceborne cloud radar and lidar observation to quantify cloud and radiation statistically and compare them in equatorial Rossby and in equatorial Kelvin waves. We found the stacked clouds from middle‐ to upper‐level in the Rossby waves and the cloud transition from low‐, middle‐, to upper‐level in the Kelvin waves. These are consistent to the precipitation characteristics, and thus these enable us to estimate apparent heat source more realistically. Consideration of the radiative heating is essential because it enhances the energy generation of the waves with 19% and 40%, for Rossby and Kelvin waves, respectively. Key Points Clouds associated with equatorial Rossby waves indicate simultaneous development from low‐ to upper‐level Clouds associated with equatorial Kelvin waves indicate gradual development from shallow, deep convection to mature mesoscale convective systems Radiative heating increase eddy available potential energy generation by 19% and 40% in Rossby and Kelvin waves respectively