Convectively generated gravity waves and their effect on the cloud environment

This study uses a two-dimensional cloud-resolving model to examine how conv ectively generated gravity waves modify the environment of an isolated conv ective cloud. The model is initialized with an idealized sounding, and the cloud is initiated by adding a locally buoyant perturbation. The modeled co nvection generates a spectrum of gravity waves with vertical wavelengths th at are harmonics of the depth of the troposphere. It is shown that the firs t three wave modes significantly modify the cloud environment. The modification of the cloud environment is quantified in terms of the con vective available potential energy (CAPE) and convective inhibition (CIN). The first two wave modes travel fastest away from the cloud and are respons ible for the changes in CAPE, whereas the third wave mode causes low-level lifting and hence a reduction in CIN. The maximum far-field perturbations i n CAPE and CIN are approximately 15% and 33% of the initial background valu es, respectively. These results agree with previous studies of more organiz ed convection, predicting the existence of a region surrounding the convect ive system that favors the development of new convection.