Discussing the effect of sampling error on the estimation of ozone variability and trend in UT/LS

One of the main focuses of the investigation of climate change is the ozone layer in the upper troposphere/lower stratosphere (UT/LS) and its relationship to temperature. Multiple studies have calculated trends at the regional and global scale in the UT/LS, using a variety of measurement methods including data from satellites and the ground. Nonetheless, the predicted trends could be greatly impacted by the coverage and quality of the measurements over time and space. Using a dataset that combines the ozonesoundings provided by SHADOZ, NDACC, and WOUDC, this work examines the effects of sampling error in the Northern Hemisphere mid-latitudes (NH, 30°N-60°N), and for different vertical layers in the UT/LS on the estimation of the ozone inter-annual variability and trends in the periods pre-2000 (1978–1999) and post-2000 (2000–2022). The vertical ozone concentration profiles are grouped into three categories, according to the temporal gaps of the historical time series, and assessed in terms of their usage for climate studies.