<p>The Earth true gravity (<strong>g</strong>) has been simplified in oceanography and meteorology into the standard gravity <strong>g</strong><sub>s</sub> (= -g<sub>0</sub><strong>k</strong>, g<sub>0</sub> = 9.81 m s<sup>-2</sup>) with <strong>k</strong> the unit vector perpendicular to the spherical surface or the normal <strong>g</strong><sub><em>n</em></sub> [= -g(φ)<strong>K</strong>] with <strong>K</strong> the unit vector perpendicular to the ellipsoidal surface. The gravity disturbance (δ<strong>g</strong> = <strong>g</strong> – <strong>g</strong><sub>n</sub>) due to nonuniform Earth mass density is totally neglected. After including the gravity disturbance into the combined Sverdrup-Stommel-Munk equation for ocean circulation, the volume transport stream-function (<strong>Ψ</strong>) is driven by both gravity disturbance forcing (GDF) and surface wind forcing (i.e., curl <strong>τ</strong>) with <strong>τ</strong> the surface wind stress. The non-dimensional <em>F</em> number (i.e., ratio of global |GDF| versus global |curl <strong>τ</strong>|) is estimated as 0.6918 using three publicly available datasets in climatological, geodetic, and oceanographic communities. Such an <em>F</em>-value (0.6918) clearly shows the comparable GDF and surface wind stress curl in driving ocean circulation, and the urgency to include the gravity disturbance in ocean dynamics. Besides, this study also cleared up some misconceptions in gravity related valuables such as vertical, geopotential, marine geoid, and dynamic ocean topography.</p>