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Introduction

Recently, large ozone depletion has been observed during early spring over the Arctic. In particular, the ozone depletion during spring 1997 exhibits many similarities to the Antarctic ozone hole from the viewpoint of the ozone distribution as well as the stratospheric general circulation. Radiative and dynamical impacts of Antarctic ozone losses on the general circulation have been investigated by several authors [e.g., Mahlman et al., 1994]. Our recent study using an interactive ozone chemistry general circulation model (GCM) showed that Arctic ozone depletion also led to decreased solar ultraviolet (UV) heating and lower temperatures, resulting in a colder and stronger polar vortex, and brought about strengthening and continuation of ozone depletion itself [Hirooka et al., 1999a, b]. Interannual variability of ozone depletion was, however, much larger in the Arctic than in the Antarctic, because of larger variability of dynamical conditions, e.g., strength of the polar vortex and planetary wave activities. The main purpose of this study is to investigate relationship between interannual variation of ozone depletion and that of the general circulation, especially in the Northern Hemisphere winter-to-spring period.