Where do winds come from? A new theory on how water vapor condensation influences atmospheric pressure and dynamics 1Theoretical Physics Division, Petersburg Nuclear Physics Institute, 188300, Gatchina, St. Petersburg, Russia
25 Jan 2013
2XIEG-UCR International Center for Arid Land Ecology, University of California, Riverside, CA 92521, USA
3School of Environment, Science and Engineering, Southern Cross University, P.O. Box 157, Lismore, NSW 2480, Australia
4Institute of Tropical Forest Conservation, Mbarara University of Science and Technology, Kabale, Uganda
5Center for International Forestry Research, P.O. Box 0113 BOCBD, Bogor 16000, Indonesia
6Centro de Ciência do Sistema Terrestre INPE, São José dos Campos SP 12227-010, Brazil
7Instituto Nacional de Pesquisas da Amazônia, Manaus AM 69060-001, Brazil
Received: 05 August 2010 – Published in Atmos. Chem. Phys. Discuss.: 15 October 2010 Abstract. Phase transitions of atmospheric water play a ubiquitous role in the
Earth's climate system, but their direct impact on atmospheric
dynamics has escaped wide attention. Here we examine and advance
a theory as to how condensation influences atmospheric pressure
through the mass removal of water from the gas phase with
a simultaneous account of the latent heat release. Building from fundamental physical principles
we show that condensation is associated with a decline in air pressure in the lower atmosphere.
This decline occurs up to a certain height, which ranges from 3 to
4 km for surface temperatures from 10 to 30 °C. We then
estimate the horizontal pressure differences associated with water
vapor condensation and find that these are comparable in magnitude
with the pressure differences driving observed circulation patterns.
The water vapor delivered to the atmosphere via evaporation represents
a store of potential energy available to accelerate air and thus drive
winds. Our estimates suggest that the global mean power at which this
potential energy is released by condensation is around one per cent of
the global solar power – this is similar to the known stationary
dissipative power of general atmospheric circulation. We conclude
that condensation and evaporation merit attention as major, if
previously overlooked, factors in driving atmospheric dynamics.
Revised: 29 April 2011 – Accepted: 03 December 2012 – Published: 25 January 2013
Citation: Makarieva, A. M., Gorshkov, V. G., Sheil, D., Nobre, A. D., and Li, B.-L.: Where do winds come from? A new theory on how water vapor condensation influences atmospheric pressure and dynamics, Atmos. Chem. Phys., 13, 1039-1056, doi:10.5194/acp-13-1039-2013, 2013.