1 Subsidence Required to Replace Heat Loss by Radiation with Work of Compression

The temperature of the troposphere is constant over the long run because energy lost by radiation is compensated for by subsidence warming. Compensating for radiative cooling requires that the troposphere subside at a velocity of approximately 500 m d-1, corresponding to subsidence mass fluxes of 5 kPa d-1 near the bottom and 1 kPa d-1 near the top of the troposphere. The mass flux decreasing in the upward direction results from surface air rising to a range of levels. The warming occurs where the air subsides and not where the latent heat of water vapour is released. The subsidence tends to occur where the atmosphere is coldest and easiest to compress. The warming produced by intense updrafts is not limited to the local area and can be distributed over the whole globe. The warming can occurs in areas remote from the updraft such as the rainless sub-tropical regions and the polar regions. The subsidence velocity is limited by warming because subsidence velocities greater than 500 m d-1 increase local temperature causing the subsidence to take place elsewhere. A subsidence velocity of 500 m d-1 (0.006 m s-1) is much lower than the typical updrafts velocity of 1 m s-1. Mass balance limits the fractional area of the updrafts to about 1 % thereby restricting possible flow regimes. There can be no classic Hadley direct or and Ferrel indirect circulation cells with upflow and downflow of approximately equal areas. A general circulation scheme consisting of fast penetrative drafts and slowly subsiding layers is proposed. The paper analyses how energy is transferred from the updrafts to the subsiding layers. The convection process transfers energy for rising air to descending air, from wherever the energy is received to wherever it radiated to space. Heat of compression is shown to be effective at transferring energy both upward and poleward