New view of atmospheric circulation

Mid-latitude storms play a major role in the global atmospheric circulation by lifting warm, moist tropical air into the upper troposphere, researchers report in the Aug. 21 issue of Science. This previously unappreciated component of atmospheric circulation may play an even more important role in a warmer and moister world, say authors Olivier Pauluis and colleagues. The conventional picture of how the atmosphere transports heat from the equator up to the poles is that air rises predominantly in the tropics, within a structure known as a Hadley Cell, and begins its movement toward the poles at high altitudes. That view, however, is based on calculations that ignore the energy content of the water vapor in the air. By including the effects of atmospheric moisture, Pauluis and colleagues now show that considerably more air rises in the mid-latitudes than was previously realized. In this new picture, nearly twice as much mass is circulated through Earth's atmosphere, and as much as half of the air ascending into the upper troposphere does so in the mid-latitudes.

ARTICLE #12: "The Global Atmospheric Circulation on Moist Isentropes," by O. Pauluis at New York University in New York, NY ; A. Czaja at Imperial College in London, UK; R. Korty at Texas A&M University in College Station, TX.