Eastward indicates a vector component which is positive when directed eastward (negative westward). Downward indicates a vector component which is positive when directed downward (negative upward). Downward eastward indicates the ZX component of a tensor. Momentum flux is dimensionally equivalent to stress and pressure. It is a tensor quantity. In accordance with common usage in geophysical disciplines
downward eastward momentum flux in air
2019-01-14
2019-01-14