The non-traditional Coriolis terms and tropical convective clouds

The full, three-dimensional Coriolis force includes the familiar sine-of-latitude terms as well as frequently dropped cosine-of-latitude terms (Nontraditional Coriolis Terms [NCT]).  The latter are often ignored because they couple the zonal and vertical momentum equations which in the large-scale limit of weak vertical velocity is considered insignificant almost everywhere.  Here, we ask whether equatorial mesoscale clouds which fall outside the large-scale limit are affected by the NCT.  A simple scaling indicates that a Lagrangian parcel convecting at 10m/s through the depth of the troposphere should be deflected over 2km to the west.  To understand the real impact of NCT, we develop a mathematical framework which describes an azimuthally symmetric convective circulation with an analytical expression for an incompressible poloidal flow.  Because the model incorporates the full 3-dimensional flow associated with convection, it uniquely predicts not only the westward tilt of clouds but...