Surface‐Atmosphere Decoupling Prolongs Cloud Lifetime Under Warm Advection Due To Reduced Entrainment Drying

An initially well-mixed stratocumulus deck can remain overcast for several tens of hours under warm-advection conditions, although moisture supply is cut off from the ocean due to surface-atmosphere decoupling (stabilization interface). In this study, a set idealized large-eddy simulations were performed investigate physical mechanism how warm-air advection impacts evolution pre-existing deck. To mimic advection, we decrease sea surface temperature linearly over time in doubly periodic domain. Given same initial more persistent when experiencing than cold-air advection. This persistence caused by reduced cloud-top entrainment drying decoupling, process influential decoupling-induced cutoff supply. notable free troposphere becomes humid. The relevance previous observations less low-level cloudiness conditions discussed.