On replenishing the depleted ozone by its photogeneration in the stratosphere

In view of the predictions that chtorofluorocarbons (CFCs) will continue to destroy stratospheric ozone for at least a century, we propose that active measures should be taken to replenish it. In particular, we propose to photolyze oxygen to ozone in the lower stratosphere by upgrading the solar light at these altitudes to short UVphotons, using solar-powered irradiation sources tethered to fixed-altitude balloons. It is estimated that the electricity produced by a 1 m² solar collector is sufficient to generate ozone at an overall yield of 3%, which in turn, is sufficient to elevate continuously the ozone level by 5% in an atmospheric column of cross-sectional area of 10,000 m². We show that it may be within reach to produce large amounts of ozone in the stratosphere by employing that conceptual approach. For instance, we provide an estimate that a total area of solar collectors of only several tens by several tens of kilometers should be sufficient to produce ozone at a rate that allows at least partial protection of the populated northern or southern afflicted latitudes. A possible configuration is that of a necklace of solar-powered lamps tethered to fixed-altitude balloons around afflicted latitudes that will illuminate the stratosphere stroboscopically. We propose to test this approach experimentally by building a stratospheric ozone station.