But convection currents are ultimately at the mercy of temperature differences because these are what create pressure differences in the first place. The pressure difference between two locations is called a pressure gradient, and the force that actually moves air as wind is called the pressure gradient force.
oÂ·nus. n. 1. A difficult or disagreeable responsibility or necessity; a burden or obligation. 2. Responsibility for an error or fault; blame: Each side wants to avoid the onus of having started the disagreement. 3.
callus. n, pl-luses. 1. (Pathology) Also called: callosity an area of skin that is hard or thick, esp on the palm of the hand or sole of the foot, as from continual friction or pressure. 2. (Pathology) an area of bony tissue formed during the healing of a fractured bone.