AbstractGrimes (1937) made a first essay to treat the passage of air across the equator dynamically. His work has been extended by Crossley (1948). In the present paper a flow pattern is presented which proves not intractable in spherical polar co‐ordinates in the equatorial belt. Frictionless horizontal flow is considered and it is shown that clockwise and counter‐clockwise circulations can exist in equilibrium on the equator. The centre of the pressure field is displaced into the hemisphere for which the circulation is cyclonic and both circulations thus appear as cyclones. It is found that trajectories and contours pass freely across the equator but that the relation between winds and contours is varia