"Climate and Forecast (CF)" . "atmosphere northward stress due to gravity wave drag" . . . . "The specification of a physical process by the phrase due_to_process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. \"Northward\" indicates a vector component which is positive when directed northward (negative southward). Atmosphere_Xward_stress is a stress which tends to accelerate the atmosphere in direction X." . .