Impact of stratospheric ozone depletion on UV penetration into the ocean at high latitudes

The effect of ozone depletion on penetration of UVB radiation through the atmosphere and into an aquatic system is investigated with the use of a newly developed radiation model pertinent for the coupled atmosphere-ocean system. The atmosphere and underlying water are each divided into a sufficient number of horizontal layers to resolve the changes in optical properties with altitude in the air and depth in the water. The model accounts for all orders of multiple scattering and the change in index of refraction across the air-water interface. The penetration of UVB radiation into the aquatic system is examined by assuming "normal" ozone abundance, taken to be 350 DU, and about 30% reduction from normal (250 DU), at 70° N. The effect of ozone depletion on the UVB penetration into the water is more pronounced in early spring than in summer. The UVB enhancements are up to 36% at the earth surface and 33% 10 meters below the sea surface on April 1 at 70° N as a consequence of ozone depletion from normal level to 250 DU.