Observation of secondary ozone peaks near the tropopause over the Korean peninsula associated with stratosphere‐troposphere exchange

Abstract

Vertical profiles of ozone partial pressure and temperature were obtained from ozonesonde measurements for 10 years from 1995 to 2004, over the midlatitude area at Pohang, Korea (36.02°N, 129.23°E), where stratosphere to troposphere exchange (STE) is very active. Secondary ozone peaks were observed in the upper troposphere/lower stratosphere at altitudes of about 14 km mostly in winter and spring. The 450 ozonesonde profiles were analyzed for this study together with satellite measurements from Halogen Occultation Experiment (HALOE) onboard the Upper Atmosphere Research Satellite (UARS). To compare with the satellite data sets, 188 HALOE data sets were archived over the period of 1993–2004 with extended locations for latitudes 32°N–40°N and longitudes of 120°E–135°E, which cover the Korean Peninsula region. The occurrence of secondary maxima in the upper troposphere is highly correlated with zonal wind speed and temperature enhancements. Most of these secondary peaks also were associated with stratosphere‐troposphere exchange processes. The backward trajectory model, Hybrid Single‐Particle Lagrangian Integrated Trajectory (HYSPLIT) from National Oceanic and Atmospheric Administration (NOAA) was used to examine these transport events further. The frequency of the secondary ozone peak appearance was found to increase at a rate of 1.4% yr−1 and 2.5% yr−1 for the past 10 years in this region on the basis of the ozonesonde and HALOE observations, respectively.