Upper-bound general circulation of coupled ocean–atmosphere: Part 1. Atmosphere

Abstract

We consider the general atmospheric circulation within the deductive framework of our climate theory. The preceding three parts of this theory have reduced the troposphere to the tropical and polar air masses and determined their temperature and the surface latitude of their dividing boundary, which provide the prior thermal constraint for the present dynamical derivation. Drawing upon its similar material conservation as the thermal property, the (columnar) potential vorticity (PV) is assumed homogenized as well in air masses, which moreover has a zero tropical value owing to the hemispheric symmetry. Inverting this PV field produces an upperbound zonal wind that resembles the prevailing wind, suggesting that the latter may be explained as the maximum macroscopic motion extractable by random eddies-within the confine of the thermal differentiation. With the polar front determined in conjunction with the zonal wind, the approximate leveling of the isobars at the surface and high aloft specifies the tropopause, which is colder and higher in the tropics than in the polar region. The zonal wind drives the meridional circulation via the Ekman dynamics, and the preeminence of the Hadley cell stems from the singular Ekman convergence at the equator that allows it to supply the upward mass flux in the ITCZ demanded by the global energy balance.

Upper-Bound General Circulation of the Ocean: A Theoretical Exposition

“…This paper completes our five-part climate theory aiming to derive the generic climate state forced only by the solar insolation [6][7][8][9]. Subjected to the bulk thermal properties previously determined, we derive the upper-bound GOC above the main thermocline when PV is homogenized, the latter being supported on theoretical, computational, and observational grounds.…”

“…In a companion paper on the general atmosphere circulation [9], we have shown that its upper bound may replicate the observed prevailing wind as well. Together with the present paper, we posit that PV homogenization provides a unifying dynamical principle for the general planetary circulations, which may be interpreted as the maximum macroscopic motion extractable by microscopic stirring-within the confines of thermal differentiation.…”

“…As depicted in Figure 1, the model GOC is divided into its constituents of the interior flow (a), the frontal jet (b), the EUC (c), the meridional boundary currents (MBC, d), recirculation (e) and the MOC (f), as discussed below in successive subsections. Although one may carry out the following derivation in spherical coordinates as in [9], the presence of boundary currents would render the mathematics unwieldy, which we deem as unwarranted given the crudeness of our model. For simplicity, we thus assume a planetary vorticity linear in the latitudinal distance, so the columnar PV (P) is…”

“…In a companion paper [9], we applied the same principles to derive the upper-bound general atmosphere circulation (GAC), which is seen to resemble the observed prevailing wind, therefore forsaking previous discordant explanations of the easterly trade winds and the polar jet stream. In the present paper, we shall show that the upper-bound GOC may replicate the observed GOC as well, including a western-intensified subtropical gyre and a counter-rotating tropical gyre feeding the equatorial undercurrent (EUC).…”

Upper-Bound General Circulation of the Ocean: a Theoretical Exposition

“…In a companion paper [9], we have applied the same principles to derive the upperbound general atmospheric circulation (GAC), which is seen to resemble the prevailing wind, forsaking therefore previous discordant explanations of the easterly trade and the polar jet stream. In the present paper, we shall show that the upper-bound GOC may replicate the observed GOC as well, including a western-intensified subtropical gyre and a counter-rotating tropical gyre feeding the equatorial undercurrent (EUC).…”