Risk-Adaptable Access Control (RAdAC) This paper considers the impediments of traditional access control approaches to sharing of. information. It describes a concept for an access control model that emulates real world decision-. making, considering operational need and security risk as part of each access control decision, and.
Turbulence can occur in the lowest part of the troposphere during the daytime when heating of the sun causes convective mixing of the air. Once the airplane rises above this turbulent boundary layer, the air becomes smoother. But other processes can also cause these up- and down-drafts.
While wind shears in the upper atmosphere are usually vertical, they tend to be horizontal closer to the runway. Horizontal wind shears can create eddies or swirls, of air that cause turbulence. A microburst is a type of wind shear associated with a thunderstorm and caused by a current of sinking air.