DISTRIBUTION OF BERYLLIUM-7 WITHIN HIGH-PRESSURE SYSTEMS IN THE EASTERN-UNITED-STATES

During a 1976 rural ozone field study conducted in McKee, Kentucky, and Busick, North Carolina, simultaneous measurements of ozone and beryllium‐7, a tracer of stratospheric air, were obtained. The purpose of this study was to assess the importance of naturally produced stratospheric ozone on ground‐level ozone concentrations observed in rural areas in the Eastern United States. It is currently accepted that the stratospheric contribution to the surface ozone is about 30‐50 ppb, and that the occurrence of this is confined to the front part of high‐pressure systems immediately behind a cold front. Furthermore, it is thought that the stratospheric contribution is negligible on the back side of the high‐pressure system where higher levels of ozone occur. This study seriously questions both of these hypotheses because the highest levels of beryllium‐7 were observed on the back side and not on the front side of high‐pressure systems. Copyright 1979 by the American Geophysical Union.