A Study of the Vertical Distribution and Sub-Peaks of Ozone below 12 km over Wuyishan Region Based on Ozone Sounding in Winter

Abstract

An understanding of the vertical distribution of ozone is critical to assessing the ozone variabilities both in the stratosphere and the troposphere. We collected the profiles of atmospheric ozone partial pressure and ozone volume mixing ratio (VMR) by a sounding system at the Wuyi Mountain National Meteorological Observation Station (Shaowu sounding station 58725) from November 2021 to February 2022. In this study, the vertical distribution and sub-peak phenomenon of tropospheric ozone below 12 km are investigated using mathematical statistics and synthetic analysis. The results show that the ozone partial pressure decreased from the ground to the tropopause, which is consistent with the temperature profile. However, 66.7% of cases first showed an increasing trend from the ground to about 3 km, while there were one or more temperature inversions in the corresponding temperature profiles and the atmosphere was stable and the relative humidity was high; then, in the stratosphere, the ozone partial pressure began to increase significantly, The ozone partial pressure reaches its maximum at an average height of 24.9 km, and the maximum value was 14 mPa. The ozone VMR in troposphere is the fluctuating increase from the ground to the tropopause, and 83.3% of the cases begin to rise rapidly at about 2–5 km away from the tropopause, and the ozone surge height is 2.9 km lower than the tropopause on average. Some of these tropopause ozone VMR have shown the characteristics of stratospheric ozone. The sub-peaks of tropospheric ozone below 12 km has four cases. All the sub-peaks occur between 6.7 km and 11.5 km vertically, and peak ozone VMR is 1.6–1.9 times larger than that of the average state at the same height. The maximum stratospheric ozone VMR is 8649 ppb on average, occurring at an average height of 31.3 km, and this average height of the maximum stratospheric ozone VMR is 6.4 km higher than that for the ozone partial pressure. The total ozone in the boundary layer (0–1.5 km) is 4.3 DU on average, accounting for 1.5% in total ozone column. The total ozone in the troposphere is 39.5 DU, accounting for 13.1% in total ozone column, and the total ozone in the stratosphere is 262.4 DU, accounting for 86.9% in total ozone column.