Seasonal variability in the vertical distribution of ozone over a tropical station, Thumba (8.5°N, 76.9°E) is investigated using nine-years (2011–2019) of ECC ozonesonde data obtained as part of Tropical Tropopause Dynamics (TTD) campaigns. Ozone exhibits a clear annual variation in the lower troposphere (0–2 km) with winter maximum (49.2 ± 3.6 ppbv) and summer monsoon minimum (21.9 ± 0.7 ppbv). In the middle (2–10 km) and upper (11–17 km) troposphere, ozone is maximum in pre-monsoon and minimum in summer monsoon. Ozone in the lower stratosphere exhibits a clear annual variation with summer monsoon maximum and winter minimum in tandem with the temperature cycle. The relative standard deviation (RSD) of ozone computed at different altitudes exhibits large intra-seasonal variability in the troposphere (~20–30%) compared to the stratosphere (~5%) and is significantly high close to the surface and in the tropical tropopause layer (TTL) (≥30%). Maximum RSD is observed during summer monsoon (June–September) in the upper troposphere (~50%) close to cold point tropopause (CPT). RSD in ozone and temperature profiles show a sharp peak immediately above the CPT in all the seasons, coinciding with the altitude of maximum wind shear. Tropospheric ozone shows an in phase relationship with temperature and is opposite in phase with water vapour. A significant negative correlation is observed between ozone and water vapour in the 2–5 km altitude region. Long-range transport and local convection contribute substantially to the observed variability in tropospheric ozone. The tropospheric column ozone shows a semi-annual variation with maximum contribution to the total columnar ozone during pre-monsoon (~16%) and minimum during summer monsoon (~8%). Mid-tropospheric ozone contributes more to the tropospheric column ozone (40–60%) compared to lower and upper tropospheric ozone. Tropospheric column ozone exhibits a similar seasonality as that of its precursors like NO₂, CO and CH₄.

使用热带热带对流层动力学（TTD）活动中获得的ECC探空仪数据的九年（2011-2019），调查了热带雨季Thumba（8.5°N，76.9°E）的臭氧垂直分布的季节性变化。臭氧在对流层下部（0-2 km）呈现明显的年变化，冬季最高（49.2±3.6 ppbv），夏季季风最低（21.9±0.7 ppbv）。在对流层中部（2-10 km）和上部对流层（11-17 km），臭氧在季风前最大，而在夏季风中最小。平流层下层的臭氧表现出明显的年变化，其夏季季风最大值和冬季最小值随温度周期而变化。与平流层（〜5％）相比，在不同高度计算的臭氧的相对标准偏差（RSD）在对流层（〜5％）中表现出较大的季节内变化（〜5％），并且在地表附近和热带地区均显着较高对流层（TTL）（≥30％）。在夏季季风（6月至9月）对流层上层（约50％）接近冷对流层顶顶（CPT）时，观测到最大RSD。在所有季节中，臭氧和温度曲线的RSD都在CPT上方立即显示一个尖峰，这与最大风切变高度一致。对流层臭氧与温度呈同相关系，与水蒸气同相。在2–5 km高度区域中，臭氧与水蒸气之间存在显着的负相关关系。远距离迁移和局部对流对观测到的对流层臭氧的变化有很大影响。对流层臭氧显示半年度变化，在季风前对总柱状臭氧的贡献最大（约16％），而在夏季风期间最小（约8％）。与较低和较高的对流层臭氧相比，对流层中层臭氧对对流层臭氧的贡献更大（40-60％）。对流层臭氧的季节性与其前驱物（如NO）的季节性相似 与较低和较高的对流层臭氧相比，对流层中层臭氧对对流层臭氧的贡献更大（40-60％）。对流层臭氧的季节性与其前驱物（如NO）的季节性相似 与较低和较高的对流层臭氧相比，对流层中层臭氧对对流层臭氧的贡献更大（40-60％）。对流层臭氧的季节性与其前驱物（如NO）的季节性相似₂，CO和CH ₄。