Land breezes are produced by cooling near the ground, which produces strong stratification and inhibits vertical motion. Nighttime cooling produces a shallower change in temperature, so the flow is not as deep. In a land breeze, the cooling produces a shallow layer of cold air, so the pressure gradient is felt only by a thin layer of air. In a sea breeze, a deep layer is heated, so the pressure gradient is felt by more air. Thus, the circulation is stronger in a sea breeze.
Friction has more of a retarding effect for the land breeze.
Both the shallow flow and stable stratification cause friction to retard land breezes much more than sea breezes. In summary, with a sea breeze the air is less stably stratified, the affected air is deeper, and friction is not as strong. All rights Reserved.