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.
Definition of usus. plural. -es. 1 Roman law : the act of making use of something : use. 2 Roman law : the personal and inalienable servitude of the usuary of making the bare use of real or personal property without enjoying its income, profit, or produce.