Gravity Wave Interactions in the Stratocumulus-Topped Boundary Layer

Stratocumulus clouds are low-level clouds that greatly influence climate. Their extensive coverage over the subtropical oceans provide a net-cooling effect via reflecting solar insolation and allowing terrestrial radiation to reemit. Previous studies across a range of scales have suggested a causal link between uncertainties in climate projections to poor prediction of low-clouds as well as positing greenhouse gas induced breakup. It is important to understand the regimes that can cause the cloud deck to dissipate which may have implications for warming under a climate change framework.



A hypothesized breakup regime is the effect of buoyancy currents, or internal gravity waves, on the stratocumulus-topped boundary layer (STBL), which are ubiquitous throughout the atmosphere. We study the effect of a gravity wave model forcing the STBL with choices of realistic wave parameters using large-eddy simulation (Cloud Model 1) in an idealized setup over a sea surface of constant temperature and present turbulent statistics and mechanisms by which the cloud layer either decouples from the surface or breaks up entirely.