31 March 2010 [Publications]
The dissipative heat engine neither explains hurricanes nor exists

Makarieva A.M., Gorshkov V.G., Li B.-L., Nobre A.D. (2010) A critique of some modern applications of the Carnot heat engine concept: the dissipative heat engine cannot exist. Proceedings of the Royal Society Series A Mathematical, Physical and Engineering Sciences, doi:10.1098/rspa.2009.0581. Abstract. PDF (0.2 Mb).

The critique presented in this paper has a rich history, see here. Its major goal is to make space for a constructive consideration of the rich physics of the condensation-induced atmospheric dynamics the major physical principle of the biotic pump of atmospheric moisture. In the press release devoted to this paper we wrote:

In a quest to understand the nature of atmospheric motions, a thermodynamic view on the atmosphere as a heat engine of some kind has become quite wide-spread. In our work we show that the dissipative heat engine where mechanical work output is supposed to grow due to internal dissipation of work produced in the previous cycles, is thermodynamically inconsistent and cannot exist. Our results indicate that the models employing the dissipative heat engine, in particular, the hurricane model of K. Emanuel, are incorrect.

This paper belongs to the series of papers on a new physical mechanism of atmospheric dynamics developed by our group. The physical core of this mechanism consists in the fact that condensation of water vapor reduces air pressure via removal of vapor from the gas phase. This leads to formation of spatial pressure gradients and thus initiates atmospheric circulation on a variety of spatial and temporal scales. In another recent paper published in November 2009 in Physics Letters A, Condensation-induced kinematics and dynamics of cyclones, hurricanes and tornadoes, it was shown that this approach yields a unified quantitative description of hurricanes and tornadoes.

However, the most important implication of the new approach concerns the role of forests in sustaining the water cycle on land. Since condensation reduces air pressure, intense condensation of water vapor associated with evapotranspiration of natural forests creates regional areas of low pressure. In the result, moist air flows from the adjacent ocean to the continent, thus compensating for the loss of water to the ocean via the river runoff. Deforestation reverses the ocean-to-land atmospheric moisture flow thus locking the continent for ocean moisture and induces rapid desertification. Conversely, restoration of a contiguous, spatially significant forest cover protects the continent against extreme weather events like both floods and droughts.

These ideas are new to the meteorological community and have been met with some resistance. This prompted us to take a critical approach to the established meteorological lines of thought (like viewing the hurricanes as a heat engine) to show that they do not provide a satisfactory explanation of the atmospheric phenomena and that there are both space and need for developing new theories.

In connection to the recently hacked CRU e-mails, the community of climate scientists has been criticized for possible distortions of the peer-review process that would keep unorthodox ideas out of the mainstream literature. In our view, our critical paper in the Proceedings of the Royal Society Series A might be a good opportunity for external observers to follow how the mainstream climate science would respond to a critique of its physical fundamentals and to what degree it is receptive to new ideas in atmospheric physics.