Abstract
Thin layers with high ozone concentration and low relative humidity (less than 20%) are frequently observed around the 500-mb level from spring to summer over Tateno. One of such cases was studied by employing the isentropic trajectory analysis.
This layer is found to be a part of the jet stream front and originates from the stratosphere. Intrusion of stratospheric air into the troposphere is associated with a high level cyclone and takes place in the rear of the cyclone. The sinking motion is most intense in the southern edge of the cyclone under the jet axis and flows from the cyclonic to the anticyclonic side of the jet axis.
