Velocity as measured in an absolute coordinate system; hence, in meteorology, the ( vector) sum of the velocity of a fluid parcel relative to the earth and the velocity of the parcel due to the earth's rotation. The east–west component is the only one affected: where and are the relative and absolute eastward speeds, Ω the angular speed of the earth's rotation, the radial distance of the parcel from the center of the earth, and φ the latitude of the parcel.