Weather Tidbits: Marine Layer Fog

This Weather Tidbits will discuss the process of marine layer fog in Delmarva. While not the only variant of fog, it is one of the more common ways fog can develop in the region. A marine layer is essentially a cool & moist ocean influenced airmass at the surface below a pocket of warmer (and likely drier) airmass a few thousand feet aloft. This creates a temperature inversion at the surface, where temperature increases with height. Air density increases as temperature decreases, so a warmer layer aloft will prevent air to rise. This traps the condensed and cooler air at the surface, hence why the air temperature and dewpoint temperature are close with each other near the surface (fully saturated air). What results is a deck of low level clouds and fog trapped at the surface.