6.1　Temporal and spatial distribution

The factors that affect atmospheric ozone distribution are air power,chemistry,and radiation processes.Ozone distributions on the global scale have strong seasonal variations due to the variation of total atmospheric ozone and the physical and chemical properties of the distribution,which are closely related to the solar elevation angle.At the same time,the changes of ozone are closely related to the weather and climate change process.Because of the differences in sea-land distribution and circulation,the total amount of ozone in northern and southern hemisphere shows different characteristics in high latitudes and regions of polar.

As a result of the signing and implementation of the Montreal Protocol in 1987,human activities that lead to ozone reduction have been effectively curbed.Since the 1990s,the global trend of atmospheric ozone reduction has been eased.Prior to the 1980s,ozone destruction was severe.Analysis of time series requires that the original data have good integrity and continuity.Moreover,the accuracy and importance attached to ozone data has been gradually improved since 1979.