Eddy diffusion in the upper atmosphere by global deposition of meteoroids

A theory for the production of eddy diffusion in the upper atmosphere by the global deposition of meteoroids is presented. It is based on the assumption that meteoroids falling on the Earth carry, on the average, a greater amount of orbital angular momentum per unit mass than that corresponding to the Earth's orbit. This excess of orbital angular momentum of the meteoroids is deposited in some or the other form during their interaction with the Earth's atmosphere. The softer material deposits the excess of its orbital angular momentum in a region slightly higher than the harder material and is held responsible for the superrotation observed in the atmosphere. It is shown that the other population of meteoroids which is metallic in nature deposits the excess orbital angular momentum below 100 km altitude and produces eddies. The size and velocity of the eddies so formed give the value of the vertical eddy diffusion coefficient in agreement with the upper limit set by Johnson and Wilkins (1965) from the study of downward heat transport in the atmosphere.