ON REPLENISHING THE DEPLETED OZONE BY ITS PHOTOGENERATION IN THE STRATOSPHERE

In view of the predictions that chlorqflurorocarbons (CFCs) will conti nue to destroy stratospheric ozone for at least a century, we propose that active measures should be taken to replenish it. In particular, w e propose to photolyze oxygen to ozone in the lower stratosphere by up grading the solar light at these altitudes to short UV photons, using solar-powered irradiation sources tethered to fixed-altitude balloons. It is estimated that the electricity produced by a I m(2) solar colle ctor is sufficient to generate ozone at an overall yield of 3%, which in turn, is sufficient to elevate continuously the ozone level by 5% i n an atmospheric column of cross-sectional area of 10,000 m(2). We sho w 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 seve ral tens by several tens of kilometers should be sufficient to produce ozone at a rate that allows at least partial protection of the popula ted northern or southern afflicted latitudes. A possible configuration is that of a necklace of solar-powered lamps tethered to fixed-altitu de balloons around afflicted latitudes that will illuminate the strato sphere stroboscopically. We propose to test this approach experimental ly by building a stratospheric ozone station.