Observational study of stratospheric ozone intrusions into the lower troposphere

To clarify the dynamic behavior of stratospheric ozone intrusion processes into the lower troposphere intensive field observations were made during the middle ten days of May 1986 covering the northern Kyushu district. The data were evaluated in conjunction with spectrophotometic total ozone data. During the study the pattern of surface ozone concentration increase was similar to those for the increase in atmospheric pressure and the decrease in specific humidity. The vertical movement of locally observed ozone peaks was consistent with the movement of a northwesterly dry air zone. An ozone peak was often accompanied by a temperature inversion layer. These observational results showed two major stratospheric ozone intrusion mechanism. At first stratospheric ozone was transported into the upper troposphere due to the descending flow near the cold front and then subsided to the surface under the subsequent high pressure system.