William Ferrel (1817 – 1891), an American meteorologist, developed theories which explained the mid-latitude atmospheric circulation cell in detail, and it is after him that the Ferrel cell is named. Year 1817 ( MDCCCXVII) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common Year 1891 ( MDCCCXCI) was a Common year starting on Thursday (link will display the full calendar of the Gregorian calendar (or a Common The United States of America —commonly referred to as the Meteorology (from Greek grc μετέωρος metéōros, "high in the sky" and grc -λογία -logia) is the Interdisciplinary Atmospheric circulation is the large-scale movement of air and the means (together with the smaller Ocean circulation) by which Heat is distributed on the surface Atmospheric circulation is the large-scale movement of air and the means (together with the smaller Ocean circulation) by which Heat is distributed on the surface
Ferrel demonstrated that it is the tendency of rising warm air, as it rotates due to the Coriolis effect, to pull in air from more southerly, warmer regions and transport it poleward. In physics the Coriolis effect is an apparent deflection of moving objects when they are viewed from a Rotating frame of reference. It is this rotation which creates the complex curvatures in the frontal systems separating the cooler Arctic air to the north from the warmer continental tropical air to the south. A weather front is a boundary separating two masses of air of different densities, and is the principal cause of meteorological phenomena.
Ferrel improved upon Hadley's theory by recognizing an until then overlooked mechanism. This is a quote from his first paper:
The fourth and last force arises from the combination of a relative east or west motion of the atmosphere with the rotatory motion of the earth. In consequence of the atmosphere's revolving on a common axis with that of the earth, each particle is impressed with a centrifugal force, which, being resolved into a vertical and a horizontal force, the latter causes it to assume a spheroidal form conforming to the figure of the earth. But, if the rotatory motion of any part of the atmosphere is greater than that of the surface of the earth, or, in other words, if any part of the atmosphere has a relative eastern motion with regard to the earth's surface, this force is increased, and if it has a relative western motion, it is diminished, and this difference gives rise to a disturbing force which prevents the atmosphere being in a state of equilibrium, with a figure conforming to that of the earth's surface, but causes an accumulation of the atmosphere at certain latitudes and a depression at others, and the consequent difference in the pressure of the atmosphere at these latitudes very materially influences its motions. 
Hadley's erroneous reasoning had been in terms of a tendency to conserve linear momentum, as air mass travels from north to south or from south to north. Ferrel recognized that in meteorology and oceanography what needs to be taken into account is a tendency of an air mass that is in motion relative to the earth to conserve the angular momentum (of its angular velocity with respect to the earth's axis).