Mechanism of Formation of the Ozone Valley over the Tibetan Plateau in Summer Transport and Chemical Process of Ozone

With the 3D chemical transport model OSLO CTM2, the valley of total column ozone over the TibetanPlateau in summer is reproduced. The results show that when the ozone valley occurs and develops, thetransport process plays the main part in the ozone reduction, but the chemical process partly compensatesfor the transport process. In the dynamic transport process of ozone, the horizontal transport process playsthe main part in the ozone reduction in May, but brings about the ozone increase in June and July. Thevertical advective process gradually takes the main role in the ozone reduction in June and July. The effectof convective activities rises gradually so that this effect cannot be overlooked in July, as its magnitudeis comparable to that of the net changes. The effect of the gaseous chemical process brings about ozoneincreases which are more than the net changes sometimes, so the chemical effect is also important.