A New Theory on Thunderstorms

Could chemical reactions be the cause of thunder-cloud development? Investigators of the electric charges in the atmosphere have naturally tended to consider largely meteorological and physical factors but recently the problem has been approached from the chemical stand-point.

Following earlier work on the mechanisms of oxidation reactions, it has been suggested that under the influence of ultraviolet radiation, water may react with oxygen molecules to f form hydrogen peroxide, which decomposes to water and free oxygen atoms. These latter being reactive might then absorb free electrons from the atmosphere to form negative ions which descend from the atmosphere with the rain. This action may be responsible for the positive charge on the major part of the atmosphere.

If these negative ions act as water-collecting nuclei, the repulsive force due to their like charges may be overcome by the effect of hydrogn bond-formation between the water atoms. Though weak in water, these bonds are strong in ice. There have been earlier observations that cold and the formation of ice are necessary for the accumulation of atmospheric electricity; the theory provides a possible explanation for this and for the generation of lightning. As the snowflakes grow heavier and fall to the warmer parts of the atmosphere, the hydrogen bonds weaken and may release the charge as an explosion which affects the whole cloud simultaneously. If the bonds weaken more gradually In regions of Intermediate temperature, the discharge may occur as the well-known St. Elmo's fire.

Among meteorologists there tends to be a certain amount of scepticism about theories since it is possible to find apparent confirmation in laboratories later disproved by observations in the atmosphere. Yet this theory does seem one which could usefully have a first critical examination in an earth-bound laboratory.