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Introduction

The sun has a 11-year sunspot cycle. Its related solar constant shows a small variation (0.1%) which is more significant in the ultraviolet spectrum than in the visible. Recently, the relationship between solar activity cycles observed summer changes of stratospheric temperature and ozone concentrations has been studied.
These observations reveal indeed that the difference between the ozone content at the solar minimum and the one at the solar maximum for an 11-year cycle differs by more or less 4%. Concerning the temperature in the stratosphere a difference of 2.0K is noticeable [Hirooka (1994)].
On the other hand, Kodera(1995) reported that in November, westerly anomalies due to the sunspot cycle appear in the midlatitudes of the upper stratosphere. These anomalies then shift poleward and downward in the following months until February.
During the same period, easterly anomalies develop first in the lower latitudes to finally intrude into the polar regions of the stratopause. As a result these easterly and westerly abnormal winds form a rotating dipole in the mid-high latitudes in winter.

The purpose of the present study is to investigate the causes of these phenomena by the use of a General Circulation Model with chemistry.